TH€SC€NeRYOF SWITZeRLAND SIR JOHN LUBBOCK ;:;? CORNELL UNIVERSITY LIEEASY. : « THl^bcok is not j^l5e taken ? ; fi'om tlHf^j^^cdmg Room. I ':■ y' SH£LF l^^^2^--/^/ ^0,(;,j,_:,>vo.(V) V^)^ 4f^ ^nuW Urnvmitg piht^tg BOUGHT WITH THE INCOME FROM THE SAGE ENDOWMENT FUND THE GIFT OF itenriS IB. Sage 1891 inAx3 '"''^T^ '''.7M r Cornell University Library QE 285.A94 The scenery of Switzerland and the cause 3 1924 004 022 137 Cornell University Library The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924004022137 THE SCENEEY OF SWITZERLAND .^^ THE SCENERY OF SWITZERLAND THE CAUSES TO WHICH IT IS. DUE BT THE EIGHT HON. SIR JOHN LUBBOCK, BART., M.P. F.R.S., D.C.L., LL.D. THE MACMILLAN COMPANY LONDON: MACMILLAN & CO., Ltd. 1896 s All rights reserved A-n^^"^ CorYEIQHT, 1896, By the MACMILLA-N COMPANY. Norfajooti ^ress J. S. Cufihing & Co. — Berwick & Smith Norwood -Mass. U.S.A. PREFACE In the summer of 1861 I had the pleasure of spend- ing a short holiday in Switzerland with Huxley and Tyndall. Tyndall and I ascended the Galenstock, and started with Benen, who afterwards lost his life on the Haut de Cry, up the Jungfrau, but were stopped by an accident to one of our porters, who fell into a deep, crevasse from which we had some difficulty in extricat- ing him, as Tyndall has graphically described in his Hours of Exercise on the Alps. From that day to this many of my holidays have been spent in the Alps. On them - 1 have enjoyed many and many delightful days ; to them I owe much health and happiness, nor must I omit to express my gratitude to the Swiss people for their kindness and courtesy. My attention was from the first directed to the in- teresting problems presented by the physical geogra- phy of the country. I longed to know what forces had raised the mountains, had hollowed out the lakes, and directed the rivers. During all my holidays these questions have occupied my thoughts, and I have read viii PREFACE much of what has been written about them. Our knowledge is indeed very incomplete : many problems still baffle the greatest Geographers ; as to others there is still much difference of opinion. Nevertheless an immense fund of information has been gathered to- gether, on many points there is a fair consensus of opinion amongst those best qualified to judge, and even where great authorities differ a short statement of their views, in a form which might be useful to those travel- ling in Switzerland, could hardly fail to be interesting and instructive. No such book is, however, in exist- ence. I urged Tyndall and several others far better qualified than I am myself, to give us such a volume, feeling sure that it would be welcome to our country- men, and add both to the pleasure and to the interest of their Swiss trips. They were all, however, other- wise occupied, but they encouraged me to attempt it, promising me their valuable assistance, and this must be my excuse for undertaking the task, perhaps pre- maturely. Tyndall we have unfortunately lost, but Professor Heim and Sir John Evans have been kind enough to take the trouble of looking through the proofs, and I am indebted to them for many valuable suggestions. The Swiss Government have published a series of excellent maps which has been prepared at the cost of the state, under the general direction of General Dufour. There is also a geological map by Studer and PREFACE IX Escher, which was admirable at the time it appeared, and has in the main stood the test of more recent researches. Studer was in fact the father of Swiss Geology ; he accumulated an immense amount of in- formation which has been most useful to subsequent authors, and if I have not quoted his researches more often, it is because I have been anxious to give the latest authorities. In 1858 he suggested that the Du- four map should be taken as the basis of a geological survey on a larger scale. To this the Swiss Govern- ment assented ; they voted the modest sum of £120, since increased to £400 a year, and appointed a com- mission consisting of Messrs. B. Studer, P. Mirian, A. Escher von der Linth, A. Favre, and E. Desor. Under their supervision the present geological map, in twenty- five sheets, has gradually appeared : the last being pub- lished in 1888, on the very day of Studer's death. In addition to the geological maps themselves, the Commission have published a splendid series of descrip- tive volumes, over thirty in number, by A. Miiller, Jac- card, Greppin, Moesch, Kaufmann, Escher, Theobald, Gillieron, Baltzer, Fritsch, Du Pasquier, Burckhardt, Quereau, Heim, Schmidt, Favre, Renevier, Gerlach, Schardt, FeUenberg, RoUe, Taramelli, and others. This is not the place to catalogue the separate Vol- umes and Memoirs on Swiss Geology and Physical Geography. Jaccard^ in his work on the Jura and 1 L. vii. , Sup. 2. X PREFACE Central Switzerland enumerates no less than 959, but among the most important I may mention Heini's mag- nificent work, Mechanismus der Gehirgshildung, Studer's Cieologie der Sohweiz, Agassiz's Etudes sur les Grlaciers, Suess's Bas Antlitz der JSrde, Favre's Recherches G-eolo- giques; for the fossils, that of Heer ; and among shorter publications, in addition to those by the geologists al- ready referred to, especially those of Bonney, Morlot, Penck, Ramsay, Riitimeyer, and Tyndall. I have dwelt specially on the valleys of the Arve, Rhone, and Rhine, the Reuss, Aar, Limmat, and Ticino as types of longitudinal and cross valleys ; and because they are among the districts most frequently visited. They have, moreover, been admirably described, espe- cially by Favre, Heim, Renevier, and Riitimeyer. I am fully conscious of the imperfections of this book : no doubt by waiting longer it might have been made better ; but I should have felt the same then also, and in the words of Favre, " il n'y a que ceux qui ne font rien qui ne se trompent pas." ^ 1 Beck. Qeul., iii. 76. CONTENTS CHAPTEE I The Geology of Switzerland The influence of geology on scenery — Difficulty of subject— Geologi- cal history of Switzerland — Igneous rooks — Gneiss — Origin of Gneiss — Granite — Porphyry — Protogine — Serpentine — Crystal- line Schists — Carboniferous period — Ancient mountain chain — Permian period — Triassic— Jurassic ; Lias, Dogger, Malm — Cre- taceous — Tertiary ; Eocene, Flysch, Nummulitic beds ; Miocene — Summary . . . . . Pages 1-18 CHAPTER II The Oeigin op Mountains Continents the true mountain ranges — Two classes of mountain ranges : table mountains and folded mountains — Peaks, two classes of: volcanoes, mountains of denudation — Origin of moun- tain ranges, cooling and consequent contraction of the earth — Crust consequently either broken up or folded — Hence table moun- tains and folded mountains — Table mountains — Cape of Good Hope — Horsts — Alps due, not to upheaval, but to folds — Amount of compression — The Jura — Amount of denudation — Dip and strike — Faults — Anticlinals and synclinals — Folding of solid rock — Proof of — Fractured fossils — Cleavage . . Pages 19-42 CHAPTEE III The Mountains op Switzerland General direction of pressure — The range due to folding, the separate summits being parts which have suffered least from denudation — The Rhone — Rhine Valley — Geotectonic valleys, and valleys of Xll CONTENTS erosion — Transverse ranges — Enormous amount of denudation — The Secondary strata formerly extended over the summits — 12,000 feet of strata probably removed from Mont Blanc — General section of Switzerland — Folds, inversion, and overthrusts — Earth- quakes — The Plain of Lombardy an area of sinking Pages 43-55 CHAPTEE IV Ice and Snow Snow-fields — The snow-line — Firn or N6v6 — Red snow — Depth of snow — Beauty of snow-fields — Avalanches — Glaciers — Structure of glacier ice — Glacier grains — Movement of glaciers — Rate of movement — Cause of movement — Regelation — Crevasses — Veined structure — Dirtbands — Moulins — Moraines — Ice tables — The glacier of the Rhone — Beauty of glaciers , Pages 56-77 GHAPTEE V The Eobmee Extension of Glaoiebs Evidence of the former extension of glaciers — Moraines and fluvio- glacial deposits — Ancient moraines, distribution of — Erratic blocks — Polished and striated surfaces — Scratched pebbles — Upper limit .of ancient glaciers — Flora and fauna — Evidence of milder interglacial periods — Limits of the ancient glaciers — Prob- able temperature of the Ice age — Table of glacial deposits Pages 78-104 CHAPTEE VI Vaileys Valleys not all due to rivers — Geotectonic valleys — Valleys of sub- sidence — Plain of Lombardy — Valley of the Rhine near Basle — Classes of valleys — Longitudinal valleys — Synclinal valleys — Anticlinal valleys — Combes — Transverse valleys — The river sys- tem of Switzerland — Two main directions — Cirques — Weather terraces — Age of the Swiss valleys . . . Pages 105-119 CONTENTS XIU CHAPTER VII Action of Rivers Three stages in river action : deepening and widening ; widening and levelling; deposition — River gorges — River cones — Cones in the Valais — Cone of the Borgne — Cones and villages — Slope of a river — River terraces — Valley of the Ticino — The Rhine — Val Camadra — Effects of floods — Giants' caldrons Pages 120-136 CHAPTER VIII Directions op Rivers Lake district — Plateau of Lannemazan — Main directions of Swiss rivers — The rivers of the Swiss Lowlands — Rivers and mountains — The Rhone and its tributaries — Changes in river courses — The tributaries of the Rhine — Former course of the Rhone — The Danube — Age of the Swiss rivers . . . Pages 137-152 CHAPTER IX Lakes Height and depth of Swiss lakes — Classes of lakes — Lakes of em- bankment, of excavation, and of subsidence — Crater lakes — Corrie lakes — Lakes due to rockf alls — The great lakes — Theories of Ramsay, Tyndall, and Gastaldi — Lakes in synclinal valleys — Lakes due to moraines — Lakes due to changes of level of the land — The Italian lakes — Color of the Swiss lakes — The Beine or Blancfond Pages 153-169 CHAPTER X The Influence of the Strata upon Scenery Character of scenery dependent on weathering, the climate, the char- acter and inclination of the rocks — Siliceous rocks — Calcareous rocks — Argillaceous rocks — Gneiss — Granite — Crystalline Schists Porphyry — Dolomite — Karrenf elder — Glaciated scenery — Moraine scenery — Rockfalls — Earth pyramids Pages 170-185 XIV CONTENTS CHAPTEE XI The Juba Jura falls into two districts : Tabular Jura and Folded Jura — Tahmlar Jura — Line of contact — Overthrust — Environs of Basle — Folded Jura — Chiaracter of tlie folds — The Vuache — The Sal6 ve — Valley of the Rhine due to subsidence — Eiver system of the Jura — The Lake of NeuchStel, Bienne, and Morat . . Pages 186-198 CHAPTER XII The Central Plain Geology — The Miocene period — Mollasse and NageMue — Coal — Oeningen — Origin of the NageMue — The pebbles of the Nagelflue — Glacial deposits — Erratics: distribution of — The river system — Changes in river courses — Excavation of the valleys Pages 199-211 CHAPTER XIII The Outer Alps General direction and character — Folds of — Compression — The Sen- tis and the Churflrsten — The Waleu See — The Rigi and Rossberg — History of the Rigi -^ Mount Pilatus — The Glarus mountains — Klippen — The My then — Stanzerhorn — Buochserhorn Pages 212-227 CHAPTER XIV The Central Massives The Alps not a single chain, but a succession of massives — Complex structure of the massives— The St. Gotthard — The tunnel — The Aar massif — Complex folding of the strata — The fan-structure — Enormous amount of denudation . . Pages 228-235 CONTENTS XV CHAPTEE XV The Lake of Geneva SizBj, height, depth, and form of the lake — The shores — The cone of the Tinifere — The surrounding heights — Conformation of the lake — The Haut Lao — The Grand Lac — The Petit Lac — The outflow — The Col between Lausanne and Neuchatel — The present out- flow— The Perte du Rhone .... Pages 236-246 CHAPTEE XVI The Massif of Mont Blanc The form of the massif — The Aiguilles Rouges — The valley of Chamouni — The Val Ferret — Protogine — The Crystalline Schists — The carboniferous Puddingstone — The glaciers — Extension of the Secondary strata over the central chain — Removal of from 10 to 12,000 feet of strata — Moraines . . . Pages 247-257 CHAPTEE XVII The Valais From Martigny to Villeneuve, a transverse valley — Rockfall of De- roohiaz — Saltmines of Bex — The cone of Bois Noir — The Dents du Midi — The Gorge of the Trient and Waterfall of Sallanohes — The change of direction at Martigny — The Haut de Cry — Sion — Sierre — The great rockfall — Leuk — The Illgraben — Moraines — Zermatt — The end of the Valais — The Rhone glacier — The Furka Pages 258-278 CHAPTEE XVIII The Beenese Oberland The Aar massif — The Bernese Oberland wall — The Aletsch glacier — The Marjelen See — The Lotschenthal — The Ferden Rothhorn and Faldum Rothhorn — The Jungfrau — The Monch — The Eiger — Meiringen — The gorge of the Aar — The valley of TJrweid — The scenery of the Oberland .... Pages 279-290 XVI CONTENTS CHAPTER XIX The Uppek Aar The Oberaar and Unteraar glaciers — Agassiz's researches — The Fall of Handeck — The Kirchet — The gorge of the Aar — The Lake of Brienz — Interlaken — The Lake of Thun — Grindelwald — Lauter- brunnen — The Staubbach — Murren — The Habkern Valley — Habkem granite — The dislocation between the lakes of Brienz and Thun Pages 291-297 CHAPTER XX ZtJEICH AND GlABUS The Lake of Ziirioh — • The view from Ziirich — The Albis and Uetli- berg — The ancient glacier — Origin of the lake — Lake terraces — The history of the Limmat : of the Sihl — The "Walen See — The Glarus mountains — The great double fold — The Glarnisch — The Windgalle Pages 298-311 CHAPTER XXI The Rhine The valley of the Rhine — The Tavetsch — Sources of the Rhine — Drainage Area of the Rhine formerly more extensive — • River ter- races — The rookfall of Films — The Averser Rhine — Churr-The gorge of the Tamina — The bifurcation of Sargans — Ancient course of the Rhine through the Lake of Zurich — Ancient moraines — The Lake of Constance — The volcanic district of Hohgau — The falls of Schaffhausen — The quarries of Oeningen — The sub- sidence of the Rhine Valley at Basle . . Pages 312-322 CHAPTER XXII The Reuss The Lake of Lucerne — Ancient course of the Reuss — The Bays of Alpnach and Kussnach — The Waggis- Vitznau basin — The Buochs- Brunnen basin — The Bay of Lucerne — The Lake of Zug The CONTEKTS Xvii rockfall of Zug — The Bay of Uri — The Upper Reuss — The Bris- tenstock — River terraces — Time required for excavation of valley — The Urnerloch — The Urserenthal — The St. Gotthard Pages 323-340 CHAPTER XXIII The Ticino The south side of the St. Gotthard —The source of the Ticino — The V. Bedretto and V. Piora — River terraces — Scenery of the Ticino — Vegetation — Use of Gneiss — Lake Cadagno and Tremorgla — Lago Maggiore — Plain of Lombardy — Immense depth of alluvial deposit — Lake of Lugano — Lago d'Orta . Pages 341-349 CHAPTEE XXIV The Engadinb The valley of the Inn — Gneiss — Granite — Crystalline Schists — Val Bevers — The Bernina — The Inn a river without ahead — Diver- sion of tributary streams — Origin of the lakes — The ancient glaciers — Monte Baselgia — Tarasp — Finstermiinz — The mineral waters — The Lower Inn Pages 350-358 CHAPTER XXY General Summary Geological history of Switzerland — Former chain of Alps — Subsi- dence — Elevation at close of Secondary period — Folding — Com- pression of 70 miles — Succession of folds — Alps comparatively recent — Denudation, probably 10 to 12,000 feet of strata removed — Excavation of valleys — The Glacial period — Former extension of glaciers — River system, causes of and changes in — Lakes, classes of, origin of — Mountains — Direction of mountain chains — Relation of north-south and east-west chains — Southward trend- ing of peninsula — General arrangement of continents and oceans Pages 359-366 Appendix . . . « . . , ' , Pages 367-371 LIST OF ILLUSTRATIONS PAGE The glacier of the Rhone .... Frontispiece 1. Cascade of Arpenaz . 24 2. Diagram in illustration of folded mountains. (After Ball) . 26 3. Hall's experiment illustrating contortion. (After Geikie) . 27 4. Diagram showing the artificial folds produced in a series of layers of clay on indiaruhber. (After Pavre) . . .27 5. Section across the Jura from Brenets to Neuchatel. (After Jaccard) 29 6. Section from Basle across the Alps to Senago, north-west of Milan. (After Kiitimeyer) 30 7. Section of the Tremettaz. (After Favre and Schardt) . . 31 8. Diagram showing the " strike " on the ground-plan A and the " dip " in the section B. (After Prestwich) . . .32 9. Monoclinal fold . 33 10. A fault. (After Geikie) 33 11. Fold-fault. Line of fault at the upper displaced bed. (After Helm and De Margerie 34 12. An inclined fold. (After Helm and De Margerie) . . 34 13. Razed folds — a, anticlinal ; 6, synclinal . . . .35 14. Diagram showing anticlinal and synclinal folds . . .35 15. Hand specimen of contorted mica schist. (After Geikie) . 38 16. Section of rothidolomite. (After Heim) . . . .39 17. Piece of stretched verrucano 39 18. Stretched and broken belemnites, half size. (After Heim) . 40 19. A fragment of nummulitic limestone. (After Heim) . . 41 20. Section of compressed argillaceous rock in which cleavage structure has been developed. (After Geikie) . . .41 21. Section of a similar rock which has not undergone this modification. (After Geikie) .,,.,, 42 six XX LIST OF ILLUSTRATIONS FIG. PAGE 22. Carboniferous trough on the Biferten Grat (Todi). (After Rothpletz) 44 23. Profile through the gneiss masses between the Khone at Viesoh and the Averserthal. (After Schmidt) ... 50 24. Section from the Weisstock across the Windgalle to the Maderanerthal. (After Heim) 51 25. Section across the Mont Blanc range. (After Favre) . . 52 26. Section across the Alps. (After Heim) . . . .53 27. Diagram showing motion of a glacier. (After Tyndall) . 66 28. Section of icefall and glacier below it, showing origin of veined structure. (After Tyndall) 67 29. Diagram showing the flow of glacier ice. (After Tyndall) . 68 30. Sketch map of the Mer de Glace. (After Tyndall) . . 69 31. View of the Grimsel . ... 79 32. Scratched boulder .... .... 80 33. Diagram showing moraine and fluvio-glacial strata. (From Le Syst. Glaciaire des Alps) 81 34. Figure representing river terraces and glacial deposits in the valley of the Aar a short distance above Coblenz. (From Le Syst. Glaciaire des Alps) ...... 82 35. Map of the country between Aarau and Lucerne ... 83 36. Diagram showing crag and tail. (After Prestwich) 91 37. View of the Brunberghorner and the Juehlistock near the Grimsel, showing the upper limit of glacial action. (After Baltzer) 92 38. Section of combe. (After Noe and De Margerie) . 106 39. Do. Do. . . 107 40. Do. Do. . . 107 41. Section from the valley of the Orbe to Mont Tendre. (After Jaccard) ... 108 42. Sketch map of the Swiss rivers ... . ill 43. Diagram in illustration of mountain structure . . . 115 44. Diagram illustrating weather teiTaces in the valley of the Bienne (Jura). (After Noe and De Margerie) . 117 45. Do. Do. . . 118 46. Diagram showing the course of a river through hard and soft strata . 118 47. The normal slope of a river 120 48. Diagrammatic section of a valley ..... 123 49. River Cone, Front view ■ . , » , .125 LIST OF ILLUSTRATIONS XXI 50. Eiver Cone. Side view 51. Map showing junction of Rhone and Borgne 52. Profiles of the principal rivers in the valley of the Garonne. (After Noe and De Margerie) 53. Slope of the principal rivers in the valley of the Garonne. (After Noe and De Margerie) .... 54. Section across the valley of the Ticino. (After Bodmer) 55. Diagram showing river terraces in Val Camadra. (After Heim) ... 56. Diagram of a river valley. Section representing harder cal- careous rock overlying a softer bed. (After Noe and De Margerie) ... .... 57. Diagram to illustrate a river now running on an anticlinal 58. Sketch map of the Rhone and its tributaries 59. River system round Chur, as it is . . 60. River system round Chur, as it used to be . 61. Section showing river terraces in the Oberhalbsteinrhein. (After Bodmer) 62. Section across the Val d'Entremont. (After Bodmer) 63. Section across the Val d'Entremont from Six Blanc to Catogne. (After Bodmer) 64. 65, 66. Diagrams to illustrate Corrie Lakes . 67. Diagram to illustrate the action of rivers and glaciers . 68. Diagram section along the Lake of Geneva. (After Ramsay) 69. Diagram illustrating the side of a lake. (After Forel) 70. Diagram showing the needleforms of the granite ridge of the Gauli. (After Baltzer) 71. Sketch map of the environs of Basle. (After Renevier and Golliez) 72. Profile of the Botzberg Tunnel. (After Milhlberg) 73. Section across the Waunenfluh. (After Milhlberg) . 74. Section across the Clos du Doubs .... 75. Section from Val Del^mont to Val Moutier . 76. Profile of the valley of Locle. (After Jaceard) . 77. Section of the Vuache with the Rhone at its foot. (After Renevier) 78. Transverse profile of the Petit Salfeve. (After Renevier) 79. Section across the Rhine Valley south of Basle. (After Schmidt) 193 80. Section across the Rhine Valley at Basle. (After Schmidt) 193 xxii LIST OP ILLUSTRATIONS FIG. ■ PAGE 81. Profile of the Val de Travers. (After Jaocard) . . . 196 82. Section of the valley of the Aar. (After Penok) . . 205 83. Section of the Mattstock. (After Burokhardt) . . .213 84. Section across the Rigi showing the rockfall of Goldau. (After Kaufmann) 215 85. Section of Kigi and the Vitznauerstock. (After Schmidt) 215 86. Diagram showing the north shore of Alps in miocene times. (After Burckhardt) .... . . 219 87. Diagram of the north shore of the Alps after the elevation. (After Burckhardt) .... ... 219 88. Section through part of the Rigi and the Eigihochflue. (After Burckhardt) 220 89. Section through Mount Pilatus. (After Kaufmann) . . 221 90. Synclinal on Mount Pilatus, near the Hotel Bellevue. (After Golliez) 221 91. Section from the Walensee to the Rhine at Films. (After Heim) ... 222 92. Section through the Roggenstock. (After Burckhardt) 224 93. Section of the St. Gotthard Tunnel. (After Stapf) . . 231 94. 95. Diagrams showing the structure of folded mountains. (After Cadell) 232 Q6. Section across the valley of the Veveyse. (After Favre) . 237 97. Map showing part of the east end of the Lake of Geneva . 238 98. Transverse profile of the valley of the Tinifere, near Ville- neuve. (After Renevier) ... . . 239 99. Section of the Tour d'Ai. (After Renevier) . . 240 100. Profile across the Lake of Geneva from Cully to Meillerie. (After Forel) 242 101. Profile across the Lake of Geneva from St. Prex to Amphion. (After Forel) 242 102. Longitudinal section of the Perte du Rhone. (After Noe and De Margerie) 244 103. Transverse section of the Perte du Rhone. (After Noe and De Margerie) . . 245 104. Section across the Mont Blanc range. (After Favre) . 248 105. Section of the Mont Blanc range from Sixt to Chamouni. (After Favre) 253 106. Photograph of the valley of Cliamouni .... 254 107. Section across the valley of the Rhone at the Bois Noir. (After Renevier) 259 LIST OF ILLUSTRATIONS XXIU FIG. PAGE 108. Section across the valley of the Ehone at Martigny. (After Renevier) 262 109. Profile of the Dents-de-Morcles. (After Golllez) . . 263 110. Summit of the Dents du Midi. (After Favre and Schardt) 264 111. Section of the Tour du Batiaz. Face of the rock from S.E. to N.W., at Martigny. (After Renevier) . . . 266 112. Section across the valley of the Lizerne. (After Renevier) 267 113. Part of the south face of the Diablerets. (After Renevier) 268 114. Section of the great wall of the Diablerets. (After Renevier) 269 115. Section of the Haut de Cry. (After Renevier) . . . 270 116. Section across the valley of the Lizerne, near Zampion. (After Renevier) 271 117. Section of the Rhone Valley at Visp. (After Fellenberg) . 273 118. Section of the Rhone Valley near Brieg. (After Schmidt) 273 119. Section of the Rhone Valley at Viesch. (After Schmidt) 274 120. Section of the Rhone Valley at Ulrichen. (After Schmidt) 276 121. Section across the Aar massif from the Doldenhorn across the Gasterenthal to the valley of Leuk. (After Fellenberg) 281 122. Theoretical section through the Ferden Rothhorn, from north to south. (After Baltzer) 283 123. Upper part of the Faldum Rothhorn. (After Fellenberg) . 283 124. View of the Jungfrau, seen from Lauterbrunnen. (After Baltzer) To face page 284 125. Map of the Haslitha), above Meiringen . . . 285 126. Section showing the calcareous wedges of the Laubstock in the Urbachthal. (After Baltzer) . . . 287 127. Section across the Justithal. (After Kaufmann) . . 295 128. Section across the Habkernthal and the Harder to the Aar. (After Kaufmann) 296 129. Section across the valley of Zuiich. (After Heim) . . 298 130. Section from the Walensee to Films. (After Heim) . . 304 131. Section across the Vorder-Rhine-Thal from Weissmeilen to Versam 305 132. Section from Mels across the Tamina valley to Chur . . 306 133. Section of the Stock-Pintga from Val Rusein, by Escher von der Linth. (From Heim) 307 134. Section across the Windgalle. (After Heim) . . 310 135. Section across the Rhine Valley at Dissentis. (After Heim) 315 136. Section across the Rhine Valley at Truns. (After Heim) 316 137. Section across the Rhine Valley at Flims. (After Heim) . 317 xxiv LIST OF ILLUSTRATIONS FIG. PAGE 138. Volcanic group of the Hohgau seen from the north-west. (After Heim) . . 320 139. Section through Rigi and Vitznauerstock . . . 324 140. Section across the Rigi from the north. (After Schmidt) . 325 141. The Bay of Uri. (After Heim) 327 142. Section of the Reuss Valley near Amsteg. (After Riitimeyer) 330 143. Reefs in the valley of the Reuss. (After Rutimeyer) . 331 144. Diagramsof section of the Reuss Valley. (After Riitimeyer) 833 145. Do . . 333 146. Section of the valley of the Ticino. (After Bodmer) . 342 147. Cross sections of the valley of the Ticino. (After Riitimeyer) .... .... 345 148. Profile through the Lower Val Tellina to Lola near Novate. (After Rolle) 347 149. Profile through the Lago Maggiore in Val Verzasca, Canton Tessin. (After Rolle) .348 150. Ideal profile of the Seegebirge and the Bernina massif. (After Rolle) . 349 151. Section across the valley of Pontresina. (After Theobald) 351 152. Profile of the Val Bregaglia. (After Bodmer) . . .353 153. Section across the valley of the Inn, from P. Julier to P. Surlei. (After Theobald) 355 154. Section of the Inn Valley at Tarasp. (After Theobald) . 357 LIST OF STRATA Recent Post Tertiary Tertiary Secondary PalEeozoic I Pliocene Miocene Eocene Cretaceous Jurassic V Trias f Permian Carboniferous Devonian ? Silurian ? Cambrian? Crystalline Schists Gneiss, etc. Principal Swiss Representatives. Glacial and Interglacial deposits Molasse and Nagelflue Nummulitic Limestone and Flysch , Cenomanian (Seewenkalk) Gault Schrattenkalk Urgonian, and Aptian Neocomian "^ Valangian I Malm (Hochgebirgskalk) I Dogger { Lias ( Keuper I Muschelkalk. Haupt Dolomite [ Bunter Sandstein Verrucano f Puddingstones, Slates, and Sand- y stone \ Various Crystalline Schists I Eruptive Kocks WORDS FOR GLOSSARY Anchitherium. An Eocene quadruped, intermediate tetween the I'apirs and the Bquida. They are regarded as ancestors of the Horse. Anticlinal, see p. 33. Archcean. The Geological Record may he classified in 5 divisions : 1, Archsean ; 2, PalsEozoio (Ancient Life) ; 3, Secondary or Mesozoio (Middle Life) ; 4, Tertiary ; and 5, Quaternary. Argillaceous Bock. Consisting of, or containing, clay. Batrachia. The group of animals to which Frogs, Toads, and Newts belong. Belemnites. Cephalopods ; allied to the Squid and Cuttlefish. Bergschrund, see p. 57. Biindnerschiefer, see p. 10. Bunter, see p. 8. Carboniferous, see p. 6. Cargneule. A rock belonging to the Triassic period. Cleavage, see p. 40. Crevasses, see p. 66. Deckenschotter, see p. 101. Dinotherium. A gigantic Mammal belonging to the Miocene period. Diorite. A rock differing from granite in containing less Silica. Dip, see p. 31. Dogger, see p. 10. Dolomite. Magnesian Limestone. Eocene, see p. 12. Erratics, see p. 86. Eyed-Oneiss, see p. 3. Felspar. Constitutes the largest portion of Plutonic and Volcanic rocks ; anhydrous, aluminous, and magnesian Silicates. Firn, see p. 57. Flysch, see p. 13. Fold Fault, see p. 32. Foraminifers. A group of microscopic shells. xxvii XXVm WOEDS FOE GLOSSAEY Gabbro, see p. 3. A group of coarsely crystalline rocks. Qault, see p. 12. Geotectonic, see p. 112, Glacier-Grain, see p. 60. Gneiss, see p. 2. Granite, see p. 4. Hauptdolomite, see p. 8. Hochgebirgskalk, see p. 11. Hornblende. A group of Silicates, so called from their horn-like cleavage, and peculiar lustre. Horst, see p. 23. Keuper, see p. 8. Lias, see p. 9. Loess, see p. 82. Magma, see p. 3. Malm, see p. 10. ilfasCodon. A gigantic quadruped, allied to the Elephant. Mesosoic, see under Archoean. Miocene, see p. 14. Mollasse, see p. 14. Monoclinal Fold, see p. 33. Moraine, see p. 71. Muschelkalk, see p. 8. Nagelflue, see p. 14. Neocomian, seep. 11. iVCTe, see p. 57. Nummnlites, see p. 13. Orthoclase. An original constituent of many crystalline rocks, including Granite, Gneiss, Syenite, etc. Outcrop, see p. 31. Palceotherium. A Tapir-like Mammal, belonging to the Eocene period. Palaeozoic, see under Archxan. Permian, see p. 7. Plagioclase. A kind of Felspar. Tschermak characterises it as a mixture of Soda Felspar and Lime Felspar. Plutonic. Igneous rocks which have consolidated below the surface. Porphyry, see p. 4. Protogine, see p. 4. Quartz. A form of Silica. Segelation, see p. 64. WOKDS FOE GLOSSAKY XXIX Schist. A rock which is split up into thin irregular plates. Secondary, see under Archman. Seewen-Limestone, see p. 12. Sericite. A talc-like variety of Mica. Serpentine, see p. 5. Slickensides, see p. 37. Strike, see p. 31. Synclinal, see p. 33. Trias, see p. 8. Urgonian, see p. 11. Valangian, see p. 11. Verrucano, see p. 6. Missing Page CHAPTER I THE GEOLOGY OP SWITZERLAND Vidi ego, quod fuerat quondam solidissima tellus, Esse fretum : vidi factas ex sequore terras ; Et procul a pelago conchse jacuere marinse. Ovid, Metam. xv. 263. Straits have I seen that cover now What erst was solid earth ; have trodden land Where once was sea ; and gathered inland far Dry ocean shells. Ovid's Metam., trans, by H. King. The Scenery of Switzerland is so greatly due to geo- logical causes, that it is impossible to discuss the pres- ent configuration of the surface, without some reference to its history in bygone times. I do not, however, pro- pose to deal with geology further than is necessary for my present purpose. The subject presents very great difficulties, not only because the higher regions are so much covered with snow, accessible only for a few weeks in the year, and in many places covered by accumulations of debris, but especially because the rocks have been subjected to such extremes of heat and pressure that not only have the fossils been altered, and often entirely destroyed, but the very rocks themselves have been bent, folded, reversed, fractured, crushed, ground, and so completely metamorphosed that in many cases their whole char- acter has been changed beyond recognition. SCENERY OF SWITZERLAND Igneous Rocks — Gneiss To commence with the Igneous series, Gneiss, which is in Switzerland as elsewhere the fundamental rock, forms in great part the central ranges, reappearing also here and there in other parts, as for instance on the Rhine at Laufen, and would it is thought be found everywhere if we could penetrate deep enough. Gneiss is composed of Quartz, Felspar, and Mica, with a more or less foliated structure. The Felspar is gener- ally white, but sometimes green or pink, and has often a waxy lustre ; the Mica is white, brown, or black. The Quartz forms a sort of paste wrapping round the other ingredients. Gneiss presents the same general characters all over the world. It is not all of the same age, and if some is comparatively recent, at any rate the oldest rock we know is Gneiss. This gives it a peculiar interest. The foliation of Gneiss is probably of two kinds : the one due to pressure, crushing, and shearing of an original igneous rock such as Granite, the other to original segregation-structure. ■' " Gneiss," says Bonney, " may be, if not actually part of the primitive crust of the earth, masses ex- truded at a time when molten rock could be reached everywhere near to the surface, and when the process of cooling, even at a very moderate depth, was much slower than it became in the ages after the earth had begun to be occupied by living creatures."^ The original crust indeed, if we use the words in their popular sense to mean the superficial layers, was 1 Heim, Beitr. z. Geol. K. d. Schw., L. xxiv. ; Geikie, Text-book of Geology. ^ Story of our Planet. I THE GEOLOGY OF SWITZERLAND 3 probably more like basalt, or the lavas of our existing volcanoes. Gneiss on the other hand must have cooled and solidified under considerable pressure and at a great depth. When we stand on a bare surface of Gneiss we must remember — and it is interesting to recollect — that it must have been originally covered by several thousand feet of rock, all of which have been removed. "Probably," says Geikie, "the great majority of geologists now adopt in some form the opinion, that the oldest or so-called 'Archsean' Gneisses are essen- tially eruptive rocks. . . . Whether they were portions of an original molten ' magma ' protruded from beneath the crust or were produced by a re-fusion of already solidified parts of that crust or of ancient sedimentary accumulations laid down upon it, must be matter of speculation. " ^ On the other hand Gneiss is certainly not all of the same age, being in some instances comparatively modern, since it traverses other strata. There are, moreover, cases in which sedimentary strata have been metamor- phosed by heat or pressure into a rock which cannot mineralogically be distinguished from Gneiss. Gneiss presents many varieties. The principal are Granite-gneiss, where the schistose arrangement is so coarse as to be unrecognisable, save in a large mass of the rock ; Diorite-gneiss, Gabbro-gneiss, composed of the materials of a Diorite or Gabbro, but with a coarsely schistose structure ; Porphyritic-gneiss or Eyed-gneiss, in which large eye-like kernels of Orthoclase or Quartz are dispersed through a finer matrix, and represent larger crystals or crystalline aggregates which have been broken down and dragged along by shearing movements in the rock. 1 Text-booh of Geology. SCENERY OP SWITZERLAND Granite Granite, like Gneiss, is composed of Quartz, Mica, and Felspar, but differs from it in not being foliated. Granite is a plutonic rock and may be of any age ; it often sends veins into the surrounding strata, which it then forces out of position, in which case they show evidence as they approach it of being much altered by heat. It solidified at a considerable depth below the surface, and its upper portions probably flowed out as lava. It presents much variation : if it shows traces of foliation it is known as Gneiss-granite. Horn- blende-granite contains Hornblende in addition to the other elements. Syenite consists of Felspar (Ortho- clase) and Hornblende. Diorite differs in containing Plagioclase instead of Orthoclase, and less Silica; if the Felspar crystals are large and well defined, it is known in popular language as Porphyry. Protogine, so named because it was formerly supposed to be the oldest of all rocks, is a Granite, containing Sericite instead of ordinary Mica. Granite, like Gneiss, must have solidified under con- siderable pressure, and therefore at a great depth. In the first place the crystals it contains could not have been formed unless the process of cooling had been very slow. In addition to this. Granite presents a great number of minute cavities containing water, liquefied carbonic acid, and other volatile substances. Sorby, whose main conclusions have since been verified by others, has endeavoured to calculate what must have been the pressure under which Granite solidified, by measuring the amount of contraction in the liquids which have been there imprisoned. He considered that the Granites which he examined must have con- I THE GEOLOGY OP SWITZERLAND 5 solidated at depths of from 30,000 to 50,000 feet. The more superficial layers probably resembled Basalt and Lava. Serpentine Serpentine is a compact or finely granular rock; olive-green, brown, yellow, or red, and has a more or less silky lustre. There has been much doubt as to its origin, but it is now regarded by many geologists as eruptive. This view is, however, by no means univer- sally accepted, at least as applying to all Serpentines. Crystalline Schists Over the Gneiss lie immense masses of Crystalline Schists, several thousand feet in thickness. No fossils have been found in them, though the presence of Graphite and seams of Limestone have been supposed to indicate the existence of vegetable and animal life. The more ancient were perhaps deposited while the waters of the ocean were still at a high temperature. So generally distributed are these Schists that in the opinion of many geologists they everywhere underlie the other stratified formations as a general platform or foundation. In parts of Switzerland, however, sedi- mentary strata have been so much modified by press^ ure, and in many cases by heat, that it is very difiicult, and sometimes impossible, to distinguish them from the older Crystalline Schists. " At one end," says Geikie, "stand rocks which are unmistakably of sedimentary origin, for their original bedding can often be dis- tinctly seen, and they also contain organic remains similar to those found in ordinary unaltered sedimen- tary strata. At the other end come coarsely crystal- line masses, which in many respects resemble Granite, 6 SCENERY OF SWITZERLAND chap. and the original character of which is not obvious. An apparently unbroken gradation can be traced be- tween these extremes, and the whole series has been termed Metamorphic from the changed form in which its members are believed now to appear." The discov- ery of fossils has indeed proved that certain Schists are Silurian, others Devonian, Carboniferous, and even Jurassic, but no Swiss geologists consider that the Crystalline Schists of the Central "Massives" of the Alps are metamorphic Mesozoic rocks. ^ The Schists are generally intensely folded and crumpled. The presence of boulders of foliated Crystalline Schist in the Carboniferous Puddingstones, proves that the foli- ation was original, or at least anterior to the Coal period.^ The problems, however, presented by these rocks are, as Geikie says, so many and difficult that comparatively little progress has yet been made in their solution. The Carboniferous Period The earliest fossiliferous rocks in Switzerland belong to the Coal or Carboniferous period. The older Cam- brian and Silurian rocks which elsewhere present so rich a flora and fauna, and attain a thickness of many thousand feet, are perhaps represented in Switzerland by some of the Crystalline Schists, though this is not yet certainly proved. A belt of Carboniferous strata extends from Dau- phine along the valley of the Isere and the Arve, presenting fossiliferous deposits at Brevent, Hiiningen, etc. It then passes along the lower Valais, and if the Verrucano belongs to this period, occupies a consider- 1 Heim, Quart. Jour. Geol. Soc. 1890. 2 Lory, Int. Geol. Cong. 1888. I THE GEOLOGY OF SWITZERLAND 7 able part of the district between the Upper Rhine and the Walensee. It is clear, however, and this indeed applies to the fossiliferous strata generally, that these beds are only remnants of- much more extensive de- posits. In places they have been removed, and in others they have been deeply buried under more recent strata. At the same time much of Switzerland is supposed to have been land at this period, probably forming a large island, or islands, while the presence in the Valais and the Mont Blanc district of Pudding- stone containing pebbles and boulders shows that there must have been some high land, and rapid streams. The Coal was probably formed in deposits somewhat similar to our peat-mosses. The vegetation consisted principally of Ferns, Mosses, Clubmosses (Lycopodiacse), and Equisetums. There appear to have been some flowering plants, but the blossoms were probably inconspicuous. Insects were represented by forms resembling the Cockroach, but there were no Bees, Flies, Butterflies, or Moths. Ba- trachia make their appearance, but there were no Mam- mals or Birds. The Verrucano, or, as it is often called, Sernifite, from the Sernfthal, is a sandy or pebbly de- posit belonging either to the close of the Carboniferous or commencement of the Permian period. Permian During the Permian period also Switzerland was partly above the sea-level, partly covered by the sea. The land appears to have gradually sunk, commencing in the east, and in the Triassic period we find evidence of deep seas, which appear to have covered the whole area of Switzerland. The name 8 SCEKBEY OF SWITZERLAND chap. " Trias " was given to it because in many districts, tliougli not everywhere, it falls into three principal di- visions, a brown, white, green, or reddish Sandstone, known as the Bunter Sandstein, the Muschelkalk or Shelly Limestone, and the Keuper, consisting of marls and limestones. In Switzerland, as in England, there are considerable salt deposits belonging to this period. Another very characteristic rock of this age is Gypsum, and the Dol- omites also belong to this period. Many mineral waters spring up from, and owe their properties to, the Triassic beds. The Keuper districts are generally rich. Dolo- mites on the contrary poor, desolate, and often almost without vegetation, but very beautiful from their rich- ness of colour, and rugged forms. The Muschelkalk is often, as for instance on the Vir- gloria pass, a hard black limestone, splitting into thin slabs, which take a good polish and are used for tables. The earliest Mammals appeared in this period. To the Trias belongs a thick deposit of gray, whitish, or yellow Dolomite, sometimes compressed into ilarble, which is known as Hauptdolomite, and especially to the east of the Rhine, forms great mountain masses, often presenting the appearance of gigantic ruins. It is unfossiliferous. The account here given of the geography of Switzer- land in past times differs, as will be seen, considerably from that indicated in the maps to Heer's Primceval World of Switzerland. Professor Heer regarded the present boimdaries of the different formations as indi- cating their original extension. This however is cer- tainly not the case. The Jurassic strata for instance were not deposited near any land. There are no shore animals nor pebbles, as there must have been if they were coast deposits. THE GEOLOGY OF SWITZERLAND Jurassic The principal Jurassic strata in Switzerland are the Lias, the Dogger, and the Malm. They attain together a thickness of over 2500 feet. During this period Ammonites and Belemnites reached their fullest devel- opment, as also did the great Sea-reptiles, the Icthyo- saurus and Plesiosaurus. At this period also flourished the flying reptiles or Pterodactyles, and we also meet the first bird (Archseopteryx), which differed from all existing species, by the possession of a long tail, and in other ways. Lias During this period the whole of Switzerland appears to have been covered by the sea. There miist however have been land not far off, as remains of Beetles, Cock- roaches, Grasshoppers, Termites, Dragon-flies, Bugs, and other Insects occur in the Lias of Schambelen, near the junction of the Reuss, the Aar, and the Limmat, and elsewhere. No Bees, Butterflies, or Moths have been met with. It is probable that the Black Forest and the Vosges were dry land. The fossils however, on the whole, indicate a deep sea. The Lias is gray or blackish, cal- careous, sandy, or argillaceous stratum. The dark colour is probably owing to the amount of organic matter which it contains. Heer suggests that the best explanation may be afforded by the Sargasso Sea. The Atlantic Ocean for an area of about 40,000 square miles is covered by Sargasso-weed so densely that ships sometimes find a difficulty in forcing their way through it. The sea is deep, and the fragments of dead weed are probably quite decayed before they reach the bot- 10 SCENERY OF SWITZERLAND chap. torn, to which they would give a dark colour. He thus explains the colour of this limestone. The "Biindner Schiefer " so largely developed in the Grisons and Valais are now considered, from the fossils which have been discovered in several places, to belong to this period. Dogger or Brown Jura Switzerland was for the most part under water at this period, but that there must have been land in the neigh- bourhood during some part of the time is proved by the existence, near Porrentruy, of beds containing sev- eral species of Limpets (Patella), Periwinkles (Pur- pura), Mussels (Mytilus), Neritas, and other shore molluscs. It is probable that the Black Forest and the Vosges were then dry land. Malm, or Upper Jurassic The Malm is characterised by a considerable develop- ment of Coral reefs, which often attained a great thick- ness. Between the Corals, which in some cases still retain their natural position, are many remains of Sea- urchins, Sponges, Molluscs, and some Crustacea, united by calcareous cement into a more or less solid rock. They are often beautifully preserved, having been em- bedded in the soft mud of a quiet sea, which extended completely over the central Alps. Indeed the southern shore of the Jurassic Sea must, in Helm's opinion, be looked for in northern Africa. The Malm is yellow and white in the Jura, blue-black in the Alps ; by its hard, bare, steeply inclined rocks, and dry sterile slopes, it gives a special character to the landscape, while the Dogger and still more the Lias, from their numerous marly layers, furnish a very i THE GEOLOGY OF SWITZEELAND 11 fertile soil. Where Malm is a dark bluish, gray, coii- choidal, calcareous rock, it is known as " Hochgehirg- skalk." In the celebrated deposits of Solenhofen many remains of Insects occur, including a Moth, the earliest Lepidopterous insect yet known. Cketaceoxjs As in the Jurassic period, so also in the Cretaceous, Switzerland was under the sea. To the east, however, was dry land. The complete difference between the animals of the Malm or Upper Jurassic, and then of the Neocomian or Lower Cretaceous, appear to imply a change of conditions or great lapse of time. It was at one time supposed^ that the southern shore of the Swiss Cretaceous Sea followed a line drawn from the Walensee to Altorf, the Lake of Brienz and Bex, but though this is the present limit of the strata they once extended much farther and have been removed by denudation. Heim considers that islands began to show themselves in the region of the Central Alps in Cretaceous times. The Swiss Cretaceous strata fall into five principal divisions. The first or oldest — Valangian^ — consists of a dark, hard, silicious, and sometimes oolitic limestone as on the Sentis, or of bluish gray marls and limestone as in the Jura. The Neocomian, from the old name of Neuch&tel, is sometimes a dark gray or black hard marl, sometimes a bluish gray marl which easily disintegrates in the air, but contains beds of excellent stone of which Neuch&tel is built. The Urgonian (so called after the town of Orgon, near Aries), or Schrattenkalk, is widely distributed in 1 Heer, FrimcBval World of Switzerland. 12 SCENERY OF SWITZERLAND chap. the Alps. It is a hard white limestone, the surface of which is often furrowed by innumerable channels, which form a perfect labyrinth. It stands in rocky walls often several hundred feet high, and from its great powers of resistance often forms the ridges and watersheds. It is arid and barren, offering a great contrast to the Neo- comian, which generally bears a luxuriant vegetation. The Gault contain many dark green grains which are a silicate of protoxide of Iron. It forms the dark bands which are so conspicuous against the paler colour of the other Cretaceous rocks. The Seewen Limestone, so called from the village of Seewen on the Lake of Lowerz, corresponds to our Chalk, and like it consists mainly of microscopic shells. The eastern and western parts of Switzerland differ con- siderably in the species. The Cretaceous deposits being of marine origin we cannot expect to know much of the land animals or plants. The forests, however, contained Cycads and Conifers, Pines, Sequoias, etc., and Dicoty- ledonous trees now make their appearance, the earliest being a species resembling a poplar found in the Cre- taceous beds of Greenland. In the upper Cretaceous strata Dicotyledons are more numerous, and it is in- teresting to find that they are mostly species in which the pollen is carried from flower to flower by the wind, or such as Magnolia, which are fertilised by beetles. Bees and Butterflies were still apparently absent or rare, and hence also the beautiful flowers specially adapted to them. Eocene At this period the formation of islands on the site of the present Alps appears to have commenced. The two principal rocks of the Eocene period are the Nummulitic Limestone and the Flysch. They represent difPerences I THE GEOLOGY OF SWITZERLAND 13 of condition rather than of time. Bands of Nummulitic Limestone often occur in the Flysch, showing that for a while the sea was favourable for the development of Nummulites. Then the conditions changed and they disappeared. This happened again and again. Nummulitic Limestone The Nummulitic Limestone is so called because it contains numerous Foraminifers, the shells of which are in some species so flattened that they resemble pieces of money. In many cases, moreover, the size increases the resemblance. The sea in which they lived was of great extent. The pyramids are built of Nummulitic Limestone, and the Nummulites are tradi- tionally said to be the petrified remains of the lentils on which the children of Israel were fed by Pharaoh. They occur also in Asia Minor, Persia, on the Hima- layas, and in Thibet, where they now rise to a height of 5000 metres. Flysch The Flysch is a very remarkable and important de- posit. The name is a local Bernese expression, which was adopted by Studer. Flysch is sometimes marly, sometimes calcareous, sometimes sandy. It is often slaty, and is extensively worked. It attains a thick- ness of nearly 2000 metres, and is evidently marine, but except in the slates of Matt, the only fossils found in it have been certain impressions which have been supposed to be Seaweeds, or perhaps Worm burrows. What are the conditions under which these have been preserved when all other organic remains have perished, is a mystery. The Flysch moimtains present soft out- lines, and their slopes present a rich carpet of vegeta- tion. 14 SCENEEY OP SWITZERLAND chap. These are the two principal deposits of the Eocene period, so far as Switzerland is concerned. In other strata numerous fossils have been found, including many Mammalia, and gven a Monkey. Miocene During this period the main elevation of the Alps took place. We should naturally expect that rapid rivers would rush down from the heights bringing masses of gravel with them, and in fact we find enor- mous deposits of coarse gravel, often cemented into a hard rock, and containing blocks six inches, a foot, and even sometimes as much as a yard in diameter. This con- glomerate is known as the Nagelflue, and the materials of which it is composed become gradually finer as we recede from the Alps, forming a more or less marly deposit known as the MoUasse. It attains a great thickness ; indeed the whole of the Rigi from the Lake of Lucerne to the summit consists of Nagelflue. The MoUasse is composed of several deposits, some fresh- water and some marine ; it is probable that the condi- tions may have been different in different parts of what are now the Swiss lowlands. The pleasant scenery of central Switzerland is greatly due to the MoUasse. The Freshwater MoUasse is generally soft, but the Marine beds afford excellent building materials. Large quantities are brought to Ziirich from the upper part of the lake. It contains beds of brown coal and is rich in fossils. Indeed the deposits at Oeningen contain perhaps the richest collection of fossils in the world. Taking the Miocene period as a whole we know nearly 1000 species of plants and 1000 insects ; of reptiles 32 species have been discovered, whereas in Switzerland now there are only 27. As regards Mammals 59 have I THE GEOLOGY OF SWITZERLAND 15 been determined, while at present Switzerland contains 62 ; but though the numbers are so nearly the same,/ the species are all different and belong to very different groups. Of the present species 15 are bats, but no bat has been found in the Swiss Miocene. It contains on the other hand no less than 25 Pachyderms. The Wild Boar is the only present representative of the order, but during the Miocene period Tapirs and tapir-like Palseo- theria, the horse-like Anchitherium, two species of Mastodon, the Dinotherium, and no less than 5 species of Rhinoceros, roamed over the Swiss woods and plains. Of plants we know already 1000 species. Many re- semble, and are probable ancestral forms of, those now flourishing in very distant parts of the world. Thus there are several Sequoias, one of which (Sequoia Langsdorfii) closely resembles the Redwood of Cali- fornia and another (Sequoia Sternbergii) the gigantic Wellingtonia. Another species resembles the Marsh Cypress of the southern United States. There are also Australian types such as Hakeas and Grevilleas, while Palms, Liquidambars, Cinnamon, Figs, Camphor trees, and many other southern forms also occur. Of Oaks Professor Heer has described no less than 35 species. Moreover many of the Miocene plants have been found in the far North, implying a comparatively uni- form and mild climate. Thus Sequoia Sternbergii is abundant in the lignites of Iceland, and Sequoia Nor- denskioldi has been found in Greenland. As a whole the flora resembles that of the present day, but repre- sented by types now scattered over the whole world, and has most aflinity with that of North America, as it contains over 200 North American against 140 Euro- pean types. They have as a rule small and wind-fer- tilised flowers. Those which are more conspicuoiis and which add so much beauty to our modern flora 16 SCENERY OP SWITZERLAND chap. were less numerous in Miocene times ; and many fam- ilies are altogether absent, such as Rosacese, Crucifers, CaryophyllaceeB, Labiatae, Primulacese, etc. Bees and Butterflies, though already existing, had not yet so profoundly modified and developed the flowers. The Miocene species were all killed off or driven south by the Glacial period and succeeded by others better able to stand a cold climate. There was on the contrary no- such complete change in the marine flora and fauna. Summary Looking at the Alps as a whole the principal axis foUoAvs a curved line from the Maritime Alps towards the north-east by Mont Blanc, Monte Rosa,^ and St. Gotthard to the mountains overlooking the Engadine. The geological strata ' follow the same direction. North of a line running through Chambery, Yverdun, Neuchatel, Soleure, and Olten to Waldshut on the Rhine are Jurassic strata ; between that line and a second nearly parallel and running through Annecy, Vevey, Lucerne, Wesen, Appenzell, and Bregenz on the Lake of Constance, are the lowlands, occupied by later Tertiary strata ; between this second line and another passing through Albertville, St. Maurice, Leuk, Meiringen, and Altdorf lies a more or less broken band of older Tertiary strata, south of which are flrst a Cretaceous zone, then one of Jurassic age, 'followed by a band of crystalline rocks, while the cen- tral core, so to say, of the Alps, consists mainly of Gneiss or Granite. If we draw a line across Switzer- land, say from Basle to Como, we find from Basle to Olten, say to the line of the Aar, Jurassic formations 1 This name has no reference to colour, but is derived from " reuse," a local name for glacier. 1 THE GEOLOGY OF SWITZERLAND 17 thrown into comparatively gentle undulations, and stretching from south-west to north-east. From Olten to Lucerne, the great plain of Switzerland is made up of upper Tertiary strata, known as MoUasse, and Nagel- flue, consisting of sand and gravel washed down from the rising mountains and deposited partly in a shallow sea, partly in lakes. At Lucerne we come upon Eocene strata, also a marine formation, which have been raised to a height as much as 2000 metres. Continuing in the same direction, and soon after passing Vitznau, we come upon Cretaceous rocks, which occupy most of the canton of Nid Dem Wald. In Ob Dem Wald we find ourselves on Jurassic. In other parts of Switzerland a considerable thickness of Triassic strata appears beneath the Jurassic, and rests on Verrucano, one of the Carboniferous series, but along our line the Jurassic region is immediately fol- lowed by Crystalline rocks, and Gneiss, forming the great Central ridge of Switzerland, and reaching as far as the Lake of Como. On the south of the mountain range, as on the north, the Gneiss is followed in suc- cession by Carboniferous, Triassic, Jurassic, Cretaceous, and Tertiary strata, but they form narrower belts. Bel- lagio is on Trias ; from the Island of Comacino the Gulf of Como is surrounded by Jurassic strata, south of which is a band of Cretaceous, running from the Lago Maggi- ore, opposite Pallanza, by Mendrisio, Como, Bergamo, and the south end of the Lago d'lseo to Brescia, and so on further to the east. Speaking roughly then we may say that the back- bone of Switzerland consists of Gneiss and Granite, followed on both sides by Carboniferous, Triassic, Jurassic, Cretaceous, and Tertiary strata. These, how- ever, are all thrown into a succession of gigantic folds, giving rise to the utmost complexity. The similarity 18 SCENERY OF SWITZERLAND chap; i of succession on the two sides of the ridge gives reason for the belief that the Carboniferous, Triassic, Jurassic, and Cretaceous strata north and south of the Alps were once continuous, and this impression is confirmed by- other evidence, as will be shown in the following chapters. CHAPTER II THE ORIGIN OF MOUNTAINS There rolls the deep where grew the tree. earth, what changes hast thou seen ! There, where the long street roars, hath been The stillness of the central sea. The hills are shadows, and they flow From form to form, and nothing stands ; They melt like mist, the solid lands, Like clouds they shape themselves and go. Tennyson. The true mountain ranges, that is to say, the elevated portions of the Eartli's surface, are the continents them- selves, on which most mountain chains are mere wrinkles ; nevertheless when we speak of mountains, we mean as a rule those parts of the land which stand high relatively to the sea-level. Mountain ranges in this sense may be classed under two main heads,^ viz. : — I. Table mountains. II. Folded mountains. The highest points or peaks may be again divided into two classes — volcanoes, and those due to weath- ering. 1 1 say " main " heads because in certain cases there may be other explanations. Von Kichthofen has suggested that the Dolomites of the Tyrol were originally coral reefs. 19 20 SCENEEY OF SWITZEELAND chap. Volcanoes Volcanoes have had comparatively little effect on the scenery of Switzerland. There is only one group of hills in Switzerland, those of Hohgau near the Lake of Constance, which is of volcanic origin. There are indeed certain isolated masses of igneoxis rock, as for instance in the Chablais, and again near Lauchern in Wandelibach, which are probably the necks of ancient volcanoes. Mountains of Denudation Let us imagine a country raised above the water with a gradual and uniform slope towards the sea. Rivers would soon establish themselves, guided by any inequalities of the surface, and running at more or less equal intervals down to the water level. They would form valleys, down the sides of which secondary rivulets would flow into the main streams. The rain and frost would denude with especial rapidity those parts of the surface which offered the least effective resistance, and thus not only would the original watershed be cut into detached summits, but secondary ridges would be formed approximately at right angles, to be again cut into detached summits like the first. The general opinion of geologists used, however, to be, in the words of Sir R. Murchison, that " most of the numerous deep openings and depressions which exist in all lofty mountains were primarily due to cracks which took place during the various movements which each chain has undergone at various periods." In support of this view such gorges as those of Pfaffers, the Trient, the Gorner, the Aar, etc., were quoted as conclusive cases, but even these are now " THE OKIGIN OF MOUNTAINS 21 proved to have been "gradually cut down by running water. The rapidity of denudation is of course affected greatly by the character of the strata, so that the pres- ent level depends pttrtly on the original configuration, partly on the relative destructibility of the rock. The existing summits are not those which were originally raised the highest, but those which have suffered the least. And hence it is that so many of the peaks stand at about the same level. Every one who has ever stood at the top of such a mountain as the Piz Lan^uard, which I name as being so easily accessible and so often visited, must have been struck by this fact; and must have noticed that the valleys are a far less important part of the whole district than they seem when we are below. The Matterhorn is obviously a remnant of an ancient ridge, which gives the peculiar straight line at the summit. The noble mass of the Bietschorn again, which forms such an imposing object as we look down the yalley of St. Niklaus across the Rhone at Visp, is a part of the surrounding granite which has resisted at- tack more successfully than the rest of the rock. The mountam crests, solid as they look from a distance, are often formed of detached fragments, shattered by storms, and especially by frost. Mountain Ranges The present temperature of the Earth's surface is due to the Sun, that supplied from the original heat of the planet being practically imperceptible. The varia- tions of temperature due to seasons, etc., do not extend to a greater depth than about 10 metres. Beyond that we find as we descend into the Earth that the heat increases on an average about 1° Fahr. for every 60 22 SCENERY OP SWITZERLAND chap. metres. 1 Even, therefore, at comparatively moderate depths the heat must be very great. Many geologists in consequence, have been, and are, of opinion that the main mass of the Earth consists of molten matter. We know, however, that the temperature at which fusion takes place is raised by pressure, and it must not, of course, be assumed that the temperature continues to in- crease so rapidly beyond a certain depth. Other great authorities,^ therefore, are of opinion that the mass of the Earth, though intensely hot, is solid, vidth, no doubt, lakes of molten matter. In either case the central mass continues slowly to cool and consequently to con- tract. The crust, however, remains at the same tem- perature and consequently of the same dimensions. This being so, under the overwhelming force of gravity one of the two things must happen. Either (1), parts of the crust must break off and sink below the rest ; or (2), the surface must throw itself into folds. Table Mountains Where the first alternative has happened we find more or less numerous faults. Those parts which have not sunk, or which have sunk less than the rest, remain as tabular mountain masses, more or less carved into secondary hills and valleys by the action of rain and rivers. Such, for instance, is the Table Mountain of the Cape of Good Hope ; its relative height is not due to upheaval, but to the surrounding districts having sunk. As the crust of the Earth cooled and solidified, cer- 1 Agassiz, however, in tlie case of the Calumet Mine near Lalie Superior, found a rate of 1° Eahr. for every 223 ft. {Amer. Journ. of Science, 1895). 2 See, for instance, Lord Kelvin, Lectures and Addresses, vol. ii. " THE ORIGIN OF MOUNTAINS 23 tain portions " set," so to say, sooner than others ; these form buttresses as it were, against which the surround- ing areas have been pressed by later movements. Such areas have been named by Suess " Horsts," a term which it may be useful to adopt, as we have no English equiv- alent. In some cases where compressed rocks have en- countered the resistance of such a "Horst," as in the north-west of Scotland and in Switzerland, they have been thrown into most extraordinary folds, and even thrust over one another for several miles. Murchison long ago expressed his surprise at the ex- istence of great plains such as those of Russia and Siberia. L. v. Buch suggested as a possible explana- tion that they rested on solid masses which had cooled down early in the history of the planet, and thus had offered a successful resistance to the folds and fractures of later ages. Folded Mountains The Swiss mountains however belong to another class, and have a very different character. They are greatly folded and compressed (see Figs. 23-26). Fig. 1 represents the Cascade of Arpenaz in the valley, of the Arve. It shows a grand arch, but does not include the whole fold, which takes the form of an S, the mid- dle part only being included in the photograph. It used to be supposed that mountains were up- heaved by forces acting more or less vertically from below upwards, and the plutonic rocks which occupy the Centre of mountain ranges, were confidently ap- pealed to in support of this view. It must be confessed that when we first visit a mountainous region, this theory seems rational and indeed almost self evident. It is now, however, generally admitted that such an explanation is untenable ; that the plutonic rocks were Fig. 1. — Cascade of Axpenaz. CHAP. II THE OEIGIN OF MOUNTAINS 25 passive and not active ; that so far from having been the moving force which elevated the mountains, they have themselves been elevated, and that this took place long after their formation. Near the summit of the Windgalle, in the Reuss district, is for instance (Fig. 24) a mass of Porphyry. The eruption of this Porphyry must have taken place before the Jurassic period, for rolled pebbles of it occur in that rock. On the other hand, the fold on the summit of the Wind- galle contains Eocene strata. The origin of the Por- phyry then is earlier than the Jurassic ; the elevation of th^ mountain is later than the Eocene. It is clear, therefore, that the Porphyry had nothing whatever to do with ther origin of the Windgalle mountain. The plutonic rocks have moreover produced no effect on the strata which now rests on them. If, however, they had been intruded in a molten condition, they must have modified the rocks for some distance around. It is evident therefore that the igneous rocks had cooled down before the overlying strata were deposited. The elevation of the Alps only commenced in the Tertiary period, but we know that the Granite of the southern Alps is, for thfe most part, pre-Carboniferous, that the Porphyry of Botzen belongs to the Permian period, the younger Porphyry to the Trias, and that the Gneiss of the central range of the eastern Alps is still older ; it is evident then, that these plutonic rocks can have taken no active part in the upheaval of the Alps, which occurred so much later. We may, indeed, lay it down as a general proposition that folded mountains are not due to volcanic action. When the two are associated, as in the Andes, the vol- canoes are due to the folding and crushing, not the folding to the volcanoes. The Alps then have not been forced up from below. 26 SCENERY OP SWITZERLAND chap. but thrown into folds by lateral pressure. This view was first suggested by De Saussure, worked out in fuller detail by Sir Henry De La Beche in 1846, and recently developed by Ball, Suess, and especially by Heini.^ Moreover, as the following sections show (Figs. 5, 23-26), we have every gradation from the simple undu- lations of the Jura (Fig. 5) to the complicated folds of the Alps (Figs. 1, 23-26). But why are the surface strata thus thrown into folds ? When an apple dries and shrivels in winter, the surface becomes covered with ridges. Or again, if we place some sheets of paper between two weights on a table, and then bring the weights nearer together, the paper will be crumpled up. Fig. 2. — Diagram in explanation of folded mountains. In the same way let us take a section of the Earth's surface A B (Fig. 2) and suppose that, by the gradual cooling and consequent contraction of the mass, A B sinks to A^B\ then to A"^ B\ and finally toA^ B'^. Of course if the cooling of the surface and of the deeper portion were the same, then the strata between A and B would themselves contract, and might consequently still form a regular curve between A^ and B^. As a matter of fact, however, the strata at the surface of our globe have long since approached a constant tem- 1 See especially Heim's great work, Untersuchungeii ii. d. Mechanis- mus d. Gebirgsbildung. I ought perhaps, however, to add that this view is not universally accepted. THE ORIGIN OF MOtlNTAINS 27 peratiire. Under these circumstances there would be no contraction of the strata between A and B corre- sponding to that in the interior, and consequently they could not lie flat between A^ and £% but must be thrown into folds, com- mencing along any line of least resistance. Sometimes, indeed, the strata are completely in- verted, and in other cases they have been squeezed for miles out Fig. 3. — Hall's Expeiimeut lllustratiug Contortion. ^The of their original position, great mountain ranges,' Geikie, " may be looked upon as the crests of the great waves into which the crust of the Earth has been thrown." Sir James Hall il- lustrated the origin of folds very simply (Fig. 3) by placing lay- ers of cloth under a weight, and then compressing the two sides, and more complete experiments have since been made by Favre, liuskin, and Cadell. Fig. 4 shows the result of one of Favre's experiments, in which he used the contraction of an indiarubber band to produce the folds 28 SCENEKY OP SWITZERLAND chap, ii The shortening of the Jura amounts to about one- fifteenth. The strata between Basle and the St. Gott- hard, a distance of 130 miles, would, if horizontal, occupy 200 miles. Heim estimates the total compres- sion of the Alps at a minimum of 120,000 metres.^ The original breadth of the strata forming the Aarmas- sif was at least double the present, and the same may be said of the central range. The Appalachians are calculated to be compressed from 150 miles to 65. It very seldom happens that such a range of moun- tains consists of a single fold. There are generally several, one being as a rule formed first, and others outwards in succession. In both the Alps and the Jura, the southern folds are the oldest. In Central America, again, there are several longitudinal ranges, and the volcanoes are generally situated on cross lines of fracture, so that they are in rows, at right angles to the general direction of the mountains ; and in almost every case the outer crater, or that towards the Pacific, is the only one now active. A glance at any good map of the Jura will show a succession of ridges running parallel to one another in a slightly curved line from south-west to north-east. That these ridges are due to folds of the Earth's surface is clear from the following figure (Fig. 5) in Jaccard's work on the Geology of the Jura, showing a section from Brenets due south to Neuchatel by Le Locle. These folds are comparatively slight and the hills of no great height. In the Alps the strata are much more violently dislocated and folded. The mountains seem so high that we are apt to ex- aggerate the relative elevation. The following figure (Fig. 6) by Riitimeyer gives the outline of the Alps from 1 Mechanismus d. Oebirgsbildung, v. 2. E a 30 SCENERY OF SWITZERLAND chap. Basle to near Milan. This section is only intended to in- ^a dicate the relative height, and is sup- ^'^ posed to follow the line of one of the ^"^ great valleys. Even so, however, it jj I ought to have shown the sudden dip to ^ a the south of the main ridge. s ^ The folded structure throws light on ail the curious fact that there are much I °, fewer faults in Switzerland than in such B,- g a region as, for instance, that of our . '^ coal fields. gZ In folded districts the contortions are < > CQ ^ 3 often so great that if we could not fol- low every step they would certainly he % ° regarded as incredible. Previous folds fig are themselves in some cases refolded, i*^ and in others the lateral pressure has §) 2 not onlv raised the strata into a vertical S o position, as for instance the Chalk and Tertiary sands of Alum Bay in the Isle a^ of Wight, but has in some cases pushed q ca 9} C3 the folds for miles, and has even thrown them over, so that the sequence is in- 1 § verted, and the more ancient lie over d "^- . the more recent strata in reverse order. CO ■i . ^ As the cooling, and consequent contrac- M ,2''^- tion of the Earth, is a continuous proc- i jjq ess, it follows that mountain ranges ■^ ^ ^ are of very different ages; and, as the B g -g summits are continually crumbling CMOS down, and rain and rivers carry away '. rt a the debris, the mountain ranges are con- a "" tinually losing height. Our Welsh hills, ^ though comparatively so small, are ven- erable from their immense antiquity, being far older. THE OKIGIN OF MOUNTAINS 31 g ^^ for instance, than the Vosges, which themselves, how- ever, were in existence while the strata now form- ing the Alps were still being deposited at the bottom of the Ocean. But though the Alps are from this point of view so recent, it is probable that the amount which has been removed is almost as great as that which still remains. They will, how- ever, if no fresh elevation takes place, be still fur- ther reduced, until noth- ing but the mere stumps remains. What an enor- mous amount of denuda- tion has already taken place is shown for in- stance in Fig. 7, repre- senting the mountain of Tremettaz near the val- leyof the Rhone, between the Niremont and the valley of the Sarine, where it is evident, not only that the strata have been cut off, but that what is now the top of the mountain was once the bottom of a valley. The edges of strata which appear at the surface of the ground are termed their "Outcrop." Sometimes they are horizontal, but if not, the inclination is termed their "Dip" (Fig. 8, B). A horizontal line, drawn at 32 SCBNEEY OF SWITZERLAND a right angle to the Dip is called the " Strike " (Fig. 8, A} of the rocks. If the surface of the ground is level, this will coincide with the outcrop. In a mountainous district such as Switzerland this is however rarely the case. Where strata have been bent, as in Fig. 9, it is called a mono- clinal fold. Where the subter- ranean forces have ruptured the strata and pushed the one side of the crack more or less upwards or downwards (Fig. 10), it is termed a fault. Faults may be small, and the difference of height between the two sides only a few inches. On the other hand, some are im- mense. In the case of one great fault described by Ramsay, the difference is no less than 29,000 feet, and yet so complete has been the denudation that the surface shows no evidence of it, and one may stand with a foot on each side, unconscious of the fact that the stratum under the one represents a geological hori- zon so much above that under the other. When the strata bent some- what before the fracture we have a fold-fault (Fig. 11). Where a fold is much compressed the limbs would become thinner and thinner (Fig. 12), while the strata in the arch and the trough would be compressed and consequently widened. THE OEIGIN OF MOUNTAINS 33 Fig. 9. — Monoclinal Fold. When the arch A, instead of being upright is thrust to one side, it is said to be inclined or recumbent (Fig. 12). Where strata are thrown into folds the convex portion is termed an anticlinal (Fig. 14, A) and the concave a synclinal (Fig. 14, 5). The same terms are applica- ble when the sur- face has been planed down so that the strata would dip as in Fig. 13. The inner strata of any fold are called the core, those of an anticlinal (Fig. 14, Ay being called the arch core, those of a syn- clinal (Fig. 14, B) the trough core. It is obvious of course that when strata are thrown into such folds, they will, if strained too much, give way at the summit. Before doing so, however, they are stretched and con- sequently loosened, while on the other hand the strata at the bottom of the fold are compress- ed; the former, therefore, are rendered more susceptible of disintegration, the latter on the contrary acquire greater powers of resistance. The diagram below, Fig. 14, represents six strata (1-6) supposed to be originally of approximately equal hardness, but which, after being thrown into undula- FlG. 10. — AFault. 34 SCENERY OF SWITZERLAND Fig. 11. — Line ol Fault at the upper displaced bed. The beds are bent near the fault by the strain In slipping. tions, are rendered more compact in the hollows and less so in the ridges. Denudation will then act more effectively at A, C, E, than at B, D, F, and when it has acted long enough the surface will be shown by the stronger line. This will be still more rapidly the case if some of the strata are softer than oth- ers. Where they are brought up to the surface erosion will of course act with special effect. Hence it often happens that hills have become valleys, and what were at first the valleys have become moun- tain tops. As an illustration of the former I may mention the Geschenenthal, and (Fig. 24) Maderanerthal, and the valley of the Tinidre (Fig. 98); of the latter, the Tremettaz (Fig. 7) or the Glaniisch. In other cases, where the summit is not at the very base of the trough, the edges of some stratum rather harder than the rest, project as two more or less pointed peaks, leaving a saddle-shaped depression in the centre. Highly inclined strata are often worn away so as to form a kind of wall, sometimes so thin that it is actually pierced by a natural hole, as for instance the Martinsloch above Elm, in Glarus. There is another Fig. 12. — An Inclined Fold. n THE OEIGIN OF MOUNTAINS 35 of these orifices near the summit of the Pilatus, one in the Marchzahn, a mountain of the Gastlose chain, and another in the Piz Aela, also known for that reason as Piz Forate, between the Albula and the Oberhalbstein Rhine. 1 When we look at these abrupt folds and complicated contortions, the first impression is that they must have Fig. 13. — Razed Folds. been produced before the rocks had solidified. This, however, is not so. They could not indeed have been formed except under pressure. We must remember that these rocks, though they are now at or near the surface, must have been formerly at a great depth, and ■where the pressure would be tremendous. Even in Fig. 14. — Diagram showing Anticlinal and Synclinal Folds. tunnels, which of course are comparatively near the surface, it is sometimes found necessary to strengthen and support the walls, which would otherwise be crushed in. The roadways in coal-mines are often forced up, especially where two passages meet. This indeed is so common that it is known as the "creeps." In deep tunnels it has not unfrequently happened that when strata have been uncovered they have suddenly bent 1 Theobald's Graubunden, Beitr. z. G-eol. Karte d. Schw., ii. 36 SCENERY OF SWITZERLAND chap. and cracked, which shows that they were under great lateral pressure. Yet the deepest mine only reaches 800 metres. Treska^ has shown by direct experiment that the most solid bodies, lead, tin, silver, copper, and even steel, will give way and "flow" under a pressure of 50,000 kilograms per square centimetre. Moreover, there is direct and conclusive evidence that the Swiss rocks were folded after solidification. In many cases contorted rocks contain veins (Fig. 16) which are in fact cracks filled up with chalcite, etc. Such fine fis- sures, however, can only occur in hard rock. Again, the Eocene contains rolled pebbles of Gneiss, Lias, Jurassic, etc., which must therefore have become hard and firm before the Eocene period,^ while the folding did not occur till afterwards. It is clear therefore that when the folding took place the rocks were already solidified. No doubt, however, the folding was a very slow process. It took place, and could only take place, deep down, far below the surface, under enormous pres- sure, and where the material was probably rendered somewhat more plastic by heat. In the later and higher rocks we find compression with fracture, in the earlier and lower rocks compression with folding. Whenever we find a fold we may be sure that, when formed, it was deep down, far below the surface. In fact folds and fractures are the two means by which the interior strains adjust themselves. They replace one another, and in the marvellously folded districts of the Alps faults are comparatively few, though it must not be supposed that they do not occur. The nature of the rock has little influence on the groat primary folds, but the character of the minor secondary 1 Comptes Eendus, 1874. 2 Heim, Mech. d. Gebirgsb., vol. ii. " THE OEIGIN OF MOUNTAINS 37 folds depends much upon it. Many of the following figures give an idea of the remarkable folds and crum- pling which the strata have undergone, so much so that they have been compared to a handful of ribbons thrown onto the ground. It is obvious that before strata could be thrown into contortions such as these, they must have been subjected to tremendous pressure. They have consequently been much altered, and the fossils have been compressed, contorted, crushed, ground, and partly, or in many cases entirely, obliterated. In parts of the great Glarus fold (see p. 100) the Hochgebirgskalk is reduced from a thickness of 450 to a few metres.^ In other cases certain formations have been completely squeezed out. We must not therefore infer from the absence of a given stratum in such cases, that it never existed. Fig. 15 represents a piece of contorted mica schist, and it will be seen that the folds are a miniature of those to which on a great scale our mountains are due. In many cases the rock is broken up into flat or more or less lenticular pieces, which have been squeezed over one another so that their surfaces have been rendered smooth and glistening. Such surfaces are known as slickensides. This process has sometimes been so in- tense and so general that hardly a piece can be found which does not present such a polished surface. The particles of stone which now touch were once far apart, others which are now at a distance once lay close together. The cracks, movements, and friction which result in such a structure must from time to time pro- duce sounds, and the mysterious subterranean noises sometimes heard are perhaps thus produced. 1 Helm, Mech. d. Gebirgsb., vol. ii. 38 SCENERY or SWITZERLAND chap. Fig. 16 represents a section of Rothidolomite, and it will be observed that, as we should expect theoretically, the strata are thinnest in the limbs, where they are squeezed out. This is visible in great mountain folds, as well as in hand specimens. Fig. 15. — Hand Specimen of Contorted Mica Schist. In the part of the curve Avhere the effect of the force is to draw out the strata, they will as shown above, if capable of giving way, become thinner. If however they are not plastic they must crack, the combined width of the cracks affording the additional THE ORIGIN OP MOUNTAINS 39 space. Fig. 17 represents a fragment of Verrucano thus drawn out. In many cases fossils are compressed or torn, but still distinguishable. Fig. 18 represents Belemnites Fig. 16. — Section of Eothidolomite. thus compressed and torn ; but in all these cases the extension or tearing is due, not to a general extension of the rock, but to lateral thrust. Fig. 17. — Piece of Stretched Verrucauo. Fig. 19 represents a piece of nummulitic limestone when the rock has not only been fractured along the lines a b, but two sides of the vein a have been evi- 40 SCENERY OF SWITZEELAND 1^ J g' .S a *-& s nil dently displaced. At a later date another fracture has taken place along the line c d. Some rocks have been so kneaded and ground together that in many places it is rare to find a cubic millimetre next its original neighbours. ^ In many places fragments and wedges of one formation have been forced into another. In the Tertiary slates of the Sernfthal at Plattenberg near Matt are well-preserved remains of fish belonging to the genus Lepidotus. Agas- siz thought he could distin- guish, and described, six species, but Wettstein has shown that they all belong to one and the same, and that the differences of form are merely due to the position in which the specimens happened to lie with reference to the direction of pressure. In many cases the pressure has produced "cleavage," and turned the rocks into shale or slate, so that they split into more or less perfect plates or films. The direction of cleav- age is quite independent of 1 Heim, Mecli. d. Oebirgsb., vol. i. THE ORIGIN OF MOUNTAINS 41 Fig. 19. — Fragment of Nummulitic Limestone. the stratification, which it may cross at any angle. Heim distinguishes three forms of cleavage. Firstly, that due to the forma- tion of slickensides as «- — - just described (^ante, p. 37). The second kind of cleavage is due to the minute particles in the rock being flattened by, and arranged at right angles to, the pressure, as shown in Figs. 20 and 21.1 The third is produced by all the laminae or elongated particles being arranged by the pressure in lines of least resistance, so that they are forced to lie parallel to one another. It is, however, by no means always easy, es- pecially in the crystal- line rocks, to distinguish cleavage from stratifica- tion. The structure of the crystalline rocks, which form the base of the Windgalle, and which Heim regards as partly stratification, is considered by some geol- ogists to be all cleavage. The fact that cleavage has been produced by press- ure was first demonstrated by Sharpe, and afterwards Fig. 20. — Section of a, fragment cf argillaceous rock. i Geikie, Text-hook of Geology. 42 SCENERY OF SAVITZBRLAND with additional evidence by Sorby and Tjmdall. In fact under great pressure solid rock behaves very much like ice in a glacier. Cleavage and folding are both due to the same cause. They have arisen simultaneously, and are different manifestations of the same mechanical action. Fig. 21. — Section of a similar rocli wliich has been compressed, and in whicli cleavage structure has been developed. CHAPTER III THE MOUNTAINS OF SWITZERLAND Erst dann haben wir ein Gebirg erkannt, wenn sein Inneres durcli- sichtig wie Glas Tor unsern geistigen Auge erscheint. — Theobald. We do not really know a mountain until its interior is to our mental eye as clear as crystal. The Swiss mountains, as indicated in the preceding chapter, are now considered to be due, not to upheaval from below, but to lateral pressure. This acted from the south-east to north-west, and took place at a comparatively recent period, mainly indeed after the end of the Eocene period. There are good grounds for supposing that a former range occu- pied the site of the present Alps at an early period, and the Carboniferous strata show considerable folds (Fig. 22), over which the Permian and more recent strata were deposited. The Carboniferous Puddingstone of Valorsine, which contains well-rounded pebbles and boulders, shows that there must have been mountains and rapid rivers at this period. These ancient mountains, however, were removed by denudation, and the whole country sunk below the Sea. Between the Eocene and the Miocene was a second period of disturbance, and all the strata, in- cluding the Eocene, were folded conformably together.^ 1 Heim, Mech. d. Gebirgsb., vol. i. 40 44 SCENERY OP SWITZERLAND chap. The main elevation of the Alps was, however, between the Miocene and the Glacial periods. Miocene strata attain in the Rigi a height of 6000 feet. By this much at least then the Alps must have been raised since the close of this comparatively recent period. " It is strange to reflect," says Geikie, " that the enduring materials out of which so many of the moun- tains, cliffs, and pinnacles of the Alps have been formed are of no higher geological antiquity than the London Clay and other soft Eocene deposits of the South of England."! . ^ .„ ^■ CrystaUihe Schists Fig. 22. — Carboniferous Folds on the Biferten Grat. Unfortunately we seldom see a map, except on quite a small scale, of the whole Alps. We have separate maps of France, of Switzerland, of Italy, and of the Austrian dominions. But to get a good general idea of the whole Alps, we require not only Switzerland, but parts of France, Italy, and Austria. If we have such a map before us we see that, with many minor irregularities, the Alps are formed on a definite plan. The principal axis follows a curved line encircling the North of Italy ; commencing with a direction almost due north in the Maritime Alps, sweeping round gradually to the east. 1 Geikie's Text-hook of Geology. HI THE MOUNTAINS OF SWITZERLAND 45 The direction appears to have been determined by the pre-existing Central Plateau of France and the Black Forest, which probably formed a continuous barrier before the subsidence of the Rhine valley. They are in fact ancient pillars, far older than the Alps, and Switzerland has been thrown into waves or folds by compression against these great buttresses. " To account for the conformation of the Alps," says Tyndall, " and of mountain regions generally, consti- tutes one of the most interesting problems of the present day. Two hypotheses have been advanced, which may be respectively named the hypothesis of fracture and the hypothesis of erosion. Those who adopt the former maintain that the forces by which the Alps were ele- vated produced fissures in the earth's crust, and that the valleys of the Alps are the tracks of these fissures. Those who hold the latter hypothesis maintain that the valleys have been cut out by the action of ice and water, the mountains themselves being the residual forms of this grand sculpture. To the erosive action here indicated must be added that due to the at- mosphere (the severance and detachment of rocks by rain and force), as affecting the forms of the more ex- posed and elevated peaks." ^ This was written thirty years ago and has been confirmed by the subsequent researches of geologists. While the folding referred to in the last chapter has determined the position of many of the Swiss valleys, "fracture" has played but a subordinate part; and to denudation and erosion, as Tyndall himself always maintained, the present conformation of the country is mainly due. 1 Tyndall, "Conformation of the Alps," Philosophical Mag., Oc- tober, 1864. See also Scrope, " On the Origin of Valleys," Geol. Mag., 1866. 46 SCENERY OF SWITZERLAND chap. Switzerland is divided roughly into equal parts by- four great rivers, — the Rhine, the Rhone, the Reuss, and the Ticino. These four rivers rise on the same great "central massif." The valleys are not, however, of the same character. The Rhine-Rhone valley from Martigny to Chur is a " geotectonic" valley ; its direc- tion coincides with the direction or "strike" of the strata, and it was originally formed by a great fold in the strata. The Reuss and Ticino valleys (except the upper part of the Reuss in the Urserenthal, which is in fact a part of the Rhone-Rhine valley and the upper part of the Ticino in the Val Bedretto, which is also a longitudinal valley) are transverse ; they cross the strata approxi- mately at right angles, and consequently the rocks on the two sides are the same. They are entirely due to erosion. In the Jura where the foldings are comparatively gen- tle and the denudation has been much less, the pres- ent configuration of the surface follows more closely the elevations and depressions due to geological changes. (See Fig. 6.) In the Alps the case is different, and the denudation has so far advanced that we can at first sight trace but little relation between the valleys, as indicated by the river courses and the mountain chains, and the geologi- cal structure of the country. There are many cases of anticlinal valleys ; that is to say, of valleys (see ante, p. 34) which run along what was at one time the sum- mit of an arch, as, for instance, the Maderanerthal (Fig. 24) and the Val de la Tiniere (Fig. 98). In other cases a piece is cut off from the rest of the massif to which it belongs, as, for instance, the Frust- horn from the Albula massif by the Valserthal. There are others where a mountain, or range of "I THE MOUNTAINS OF SWITZERLAND 47 mountains, occupies the line of a former valley. This is the case for instance with the mountain ridge which runs between the Rhine and. the upper Linth from the Kistenpass at the head of the Limmerbach to the south of the Limmern Glacier, by the Bifertenstock to Piz Urlaun and Stock Pintga or the Stockgron.i This range of mountains occupies the site of an original valley, but no doubt from the greater hardness of the rock and its position it has offered a more successful resistance to attack ; while the original mountains have been washed away. In this way some at any rate of the transverse ranges have, as it were, been carved out. Thus the Safienthal — the valley of the Glenner which falls into the Rhine at Ilanz — is bounded by ranges approximately at right angles to the main direction of the mountains. That on the left of the valley culminates in the Piz Ricin, Crap Grisch, Weissensteinhorn, and Barenhorn. In favourable light it can easily be seen from the opposite side of the valley, that the streams have cut out the valleys and are thus the cause of the mountains. This is a particularly clear illustration, because the strata are uniform along the whole line, so that the structure is not complicated by the presence of rocks. of different character and hardness. Indeed if we compare together two maps, in one of which the principal chains of movintains, and in the other the main river valleys are brought out most prominently, they look at first sight so different that we should hardly suppose them to represent the same district. 2 It is evident therefore that the main agent which has determined many of the river valleys i-s not 1 Helm, Beitr. z. Geol. K. d. Schw., L. xxv. ' Heim, Mech. d. Gebirgsb., vol. i. 48 SCENERY OF SWITZERLAND chap. that which has given rise to the mountains. The courses of the rivers, though there have, as we shall see, been many minor changes, and exceptions due to other causes, still were determined by the folds into which the sur- face was thrown; while the present mountain summits are mainly the result of erosion and denudation. We will now consider the evidence which leads to the conclusion that the fossiliferous strata formerly extended over the Central chain of the Alps. It is a common error to suppose that the limits of geological strata are those which are now shown on the map. It requires little reflection however to show that tliis was not so. In the abyssal depths of the ocean deposit is portentously slow, and a long period would be repre- sented by only a few inches of rock. Moreover, though a marine formation proves the existence of sea, the absence of a marine formation does not prove the ex- istence of land. Strata may and often have been en- tirely removed. Our Cretaceous deposits for instance once extended far beyond their present limits. The same was the case with the Secondary deposits of Switzerland from the Trias to the Eocene. They ex- tended completely over the Central mountains. If these mountains had been then in existence and the Secondary strata had been deposited round them, we should find evidence of shore deposits, with remains of animals and seaweeds such as live in shallow waters and near land. This is however not the case, we find no pebble beds such as would be the case near a shore, no gravels with pebbles of granite, gneiss, or crystalline schists, but deep-sea deposits of fine sediment evidently formed far from land. The southern shores of the Jurassic Sea were perhaps far away in Africa, i In the 1 Heim, Mech. d. Gebirgsb., vol. ii. ; Baltzer, Beitr. z. Geol. K. d. Schw., L. xxiv. HI THE MOUNTAINS OF SWITZERLAND 49 Triassic period there seems to have been a barrier be- tween the Eastern and Western Alps, but subsequently the conditions must have been very similar. Even the Eocene deposits- show no evidence of a shore where the Alps now rise above them. We have other proofs that the central chains were formerly covered by other strata. For instance, the Puddingstone of Valorsine at the head of the Cha- mouni valley, which belongs to the Carboniferous period, contains no granite or porphyry pebbles. The granite and porphyry strata of the district must therefore at that period have been protected by a covering of other rocks which have been since stripped off. It is also significant that the pebbles of the Miocene Nagelflue which come from the neighbourhood are mainly of Eocene age. Neither the Crystalline rocks nor the older Secondary strata seem to have been then as yet uncovered. ^ There are indeed Crystalline and Triassic pebbles in the Nagelflue, for instance, of the Rigi, but they do not belong to rocks found in the valley of the Reuss or on the St. Gotthard. They resemble those of Lugano, Bormio, the Julier, and other districts far away to the south-east. We are not however dependent on these arguments alone, conclusive as they are. Remains of Secondary strata occur here and there in the Central district, and these are not fragments torn away from one another, but parts of a formerly continuous sheet which have been preserved in consequence of being protected in the hollows of deep folds. That the Secondary strata were once continuous over the Central chain is well shown in the following figure (Fig. 23) drawn from the Rhone to the Averserthal and cutting the Binnen- Heim, Mech. d. Gebirgsb., vol. ii. 50 SCENEKY OF SWITZERLAND chap. thai, Val Antigorio, Val Bavena, Val Maggia, Val Ticino, Val Blegno, Val Misocco, and Val St. Giacomo. It will be seen that all these valleys are primarily due to great folds, and that in each ^1 M ^ Btf"^"? case we find at the bottom of the J, Heim, from the Weisstock across ^ g S 5 'r" the Windgalle to the Maderauer- -,- .- 1 -J- been cut out of the Crystalline £ "?!. I S .if " rocks, s, and was once covered by S ■" I 'it, t^s Jurassic strata /, which must i a .3 I S ^ have formerly passed in a great 11 !"-!>■§ arch over what is now the valley. i I H- -?"s' Again it is clear (Fig. 25) that r= '^. •- i ^ o a great thickness of Crystalline s'~< i^ « I rock has been removed from the S .fc ^ •§ n rh summit of Mont Blanc. No doubt oi'oM' -S (®®^ ante^ p. 6) many thousand 5 rt'-g'Tl-'S feet had been removed before the ^ ^.-5 i "I oj- deposition of the Secondary strata. li; ^ '^ g -^ o But even since its elevation the '.5 I "3 ^ i amount of erosion of the Granite ^ » g ^ ^ § itself has been considerable. How £ much we do not know, but 500 metres would probably be a mod- erate estimate. To this must be added the Crystalline Schists, say 1000 metres, and the Sedimentary rocks, which from what we know of their thickness elsewhere cannot be taken at less than 3000 metres. This there- THE MOUNTAINS OF SWITZERLAND 51 fore gives 4500 metres, or say 14,000 feet, whicli erosion and denudation have ^ stripped from tlie °-' ^ summits of the moun- tains! Fig. 26 gives a section across the Alps, and it will be seen that the section across the St. Gott- hard substantially re- sembles that of Mont Blanc. Surprising, and even almost incredi- ble, as this may at first sight appear, it becomes less difficult to believe when we remember that not only the great Mio- cene gravel beds which form the Cen- tral plain of Switzer- land, but much of the deposits which occu- py the valleys of the Rhine, Po, Rhone, Reuss, Inn, and Dan- ube — the alluvia which form the plains of Lombardy, of Ger- many, of Belgium, Holland, and of south- east France, are ma- terials washed down from the Swiss mountains. 52 SCENERY OP SWITZERLAND It is calculated that at the present rate of erosion the Mississippi removes one foot of ma^ terial from its drainage area in 6000 years, the Ganges above Ghazipur in 800, the Hoangho in 1460, the Rhone in 1500, the Danube in 6800, the Po in 750. Probably therefore we may take the case of the Rhone as approximately an aver- age, and this gives us, if not a measure, at any rate a vivid idea of the immense length of time whichmust haveelapsed. The great plain shows comparatively gentle elevations, which be- come more marked in the " Prealps," while the inner chains are thrown into the most extreme contortions. In some cases the result of compression has been to push certain strata bod- ily over others. Such overthrusts also greatly tend to render the relief of the surface indepen- dent of the tectonic THE MOUNTAINS OF SWITZERLAND 53 structure. If there were no over- thrusts, if the arches had been flatter and the troughs broader, the causes which have led to the present con- figuration of the surface would have been much clearer. The main ranges then are due to compression and folding, the peaks to erosion, and the three main factors in determining the phj^sical geography of Switzerland, have been compression, folding, and denudation. The present configuration of the surface is indeed mainly the result of denudation, which has produced the greatest effect in the Central portions of the chain. It is prob- able that the amount which has been removed is nearly equal to that which still remains,^ and it is certain that not a fragment of the original surface is still in existence, though it must not be inferred that the mountains were at any time so much higher, as elevation and denudation went on together. This leads us to the considera- tion whether the Alps are still rising. On this subject we have no absolute proof. The country is now, however, so well mapped that if changes are still going on 1 Heim, Beitr. z. Cfeol. K. d. Schw., L. xxv. 0// ■*r g \ w';'/ ' w °s| [m la N "1 -3-^^.; L V /''q'' CO § /cM p tS~' N ■ 1""' "=^ ( / J'S / 'vW-Tri- / . si ?Ji ■ v-+^~~v} --y '— '5 'J ■S*^! CO 1^1 \ //^feff y. » \ ''■ -tH'-^' AS- ii... *)• E=> y / ■*^ IrT-jr ^-'' CO ^J / /m^_ m ^. 2 il '''-a:~AK^ 7! If a 1 el. .^aK^' « t d '-'■Tj^mf'. •^ 1 g.. O ~"W tS ""«; i i -S-t^i^i. o H Ul^^S A Cf^? ■\\ 1 ^" •<# y S- \ 1 ) ->i ^■' K''^' 1%^^ .' uJ-^J/;ij .t (m ..\ ■!^ 5-i SCENERY OF SWITZERLAND chap. they must erelong show themselves. It is probable on mechanical and geological grounds that the southern chains were formed first, and the northern ones after- wards in order of succession. It has been shown that the Secondary strata originally covered the whole area, and their removal from the Central massives, except in the deeper folds, is strong evidence of their great age. There is no proof of any present movement in this Central district. On the other hand slight earthquakes are common in Switzerland ; more than 1000 have been recorded during the last 150 years, and no doubt many more have passed unnoticed. This appears to indicate that the forces which have raised the Alps are perhaps not entirely spent, and that slow movements may be still in progress along the flanks of the mountains. ^ Many of these earthquakes are very local and as a rule not deep seated, at a depth of not more than from 15,000 to 20,000 metres. Even however in the Central Alps there is still some evidence of continual strain. When the tunnels were being pierced for the St. Gotthard line, and especially the Wattinger tunnel near Wasen, slight explosions were often heard, and blocks of rock were thrown down on the workmen. These generally came from the roof, but sometimes from the sides, and eventually it was found necessary to case the interior of the tunnel.^ These phenomena, however, may have been only due to the great pressure. The American geologists, and especially Dana, have pointed out that folded mountains are not as a rule symmetrical but one-sided. Suess^ has extended this to Switzerland and indeed to folded mountains gener- 1 Heim, Mech. d. Qehirgsh., vol. ii. 2 Baltzer, Beitr. z. Q-eol. E. d. Schto., L. xxiv. ^ Das Antliz der Erde. Ill THE MOUNTAINS OP SWITZERLAND 65 ally. It is remarkable that in all the European moun- tain systems — the Alps, Apennines, Jura, Carpathians, Hungarian Mountains, etc., the outer side of the curve presents a succession of folds which gradually diminish in intensity, while the inner side terminates in an im- mense fold, the anticlinal, or arch of which, in the case of Switzerland, constitutes the outer crest of the Alps, while the synclinal, or area of depression, has given rise to the great valley of the Po, which appears to be an area of sinking. The Jura rises gently from the north-west, and cul- minates in the steep wall which bounds the Central plain of Switzerland. The Ural Mountains and their continuation, the islands of Novaya Zemlya, are steep on the eastern side. In fact, the Urals are not so much a chain of mountains, as a tilted surface, with a sudden fracture, and a sunken area to the east.^ The Indian Ghats again present a very steep side to the sea. The Hima- layas which in so many respects resemble the Alps, the Rocky Mountains, the Green Mountains, the AUe- ghanies, etc., are also one-sided ; and South America slopes up from the east to the great wall of the Andes which towers over the Pacific Ocean. The Alps are a most delightful, but most difficult study, and although we thus get a clue to the general structure of Switzerland, the whole question is ex- tremely complex, and the strata have been crumpled and folded in the most complicated manner, sometimes completely reversed, so that older rocks have been folded back on younger strata, and even in some cases these folds again refolded. 1 Suess, Die Entstehung Her Alpen. CHAPTER IV SNOW AND ICE — SNOWPIELDS AND GLACIERS "Chaque ann^e je me livre k de nouvelles recherches, et en me proourant un genre de jouissance peu connu du reste des liommes, celui de visiter la nature dans quelques-uns de ses plus hauts sanctu- aires, je vais lui demander I'initiation dans quelques-uns de ses mys- tferes, oroyant qu'elle n'y admet que ceux qui sacriflent tout pour elle et qui rendent des hommages contiiiuel." — Dolomieu, Journal des Mines, 1798. The height of the snow-line in the Alps differs ac- cording to localities and circumstances, but may be taken as being from 2500 to 2800 metres above the sea-level. The snowfields are very extensive, the expanse of firn being necessarily greater than that of the glacier proceeding from it. The annual fall of snow gives rise to a kind of strati- fication, which however gradually disappears. The ac- tion of the wind tends, on the whole, to level the surface, leaving however many gentle undulations, and heaping up the snow in crests and ridges. Here it often forms cornices, which on the mountains sometimes project several feet. I shall never forget my sensations, when standing with Tyndall on, as I supposed, the solid sum- mit of the Galenstock, he struck his alpenstock into the snow, and I found that we were only supported on such a cornice projecting over a deep abyss. When the snow falls at a temperature of 0°-12°, it assumes the form of stars or eight-sided crystals. 56 CHAP. IV SNOW AND ICE 57 The region affected by glacial action may be divided into three parts : — 1. The firn or neve. 2. The glacier. 3. The region of deposit. The Firn or Neve The snow which falls in the higher Alpine regions, by degrees loses its crystalline form, becomes granular, and is known as Neve or Firn. It can be distinguished at a glance from recent snow by being less brilliantly white, partly because it contains less air, partly because the particles of meteoric and other dust give it a slightly yellowish, gray, or even brownish tinge. Sometimes it is in patches quite red. This is generally due to the presence of a minute alga, Sphaerella nivalis. There are, however, several other minute organisms, plants. Infusoria, and Rotifera (Philodina roseola) of a red or brownish colour. The firn is generally firm. When the temperature is low, it becomes quite hard ; except on hot days the foot sinks but little into it ; usually it remains dry. The water which results from melting sinks into it, and freezes the snow below into a solid mass, which has a more or less stratified appearance, each yearly deposit forming a layer from one to three feet in thickness, which can sometimes be traced even to the lower end of the glacier. The firn attains in many places a great depth. Agassiz estimated that of the Aar glacier at 460 metres.^ It moves slowly down- wards, and when its upper end terminates against a rock wall, which of course retains its position, a deep gap is formed in spring, known as a Bergschrund, which widens 1 Systeme Glaciaire. 58 SCENERY OP SWITZERLAND chap. during the summer and autumn, gradually fills up in winter, and reappears the next year. It is impossible to give any idea in words of the beauty of these high snowfields. The gently curving surfaces, which break with abrupt edges into dark abysses, or sink gently to soft depressions, or meet one another in ridges, the delicate shadows in the curved hollows, the lines of light on the crests, the suggestion of easy movement in the forms, with the sensation of complete repose to the eye, the snowy white with an occasional tinge of the most delicate pink, make up a scene of which no picture or photograph can give more than a very inadequate impression, and form an almost irresistible attraction to all true lovers of nature. The firn would accumulate and increase in thickness indefinitely if it were not removed, (1) by melting and evaporation, (2) by avalanches, and (3) by slow descent into the valley. Avalanches Avalanches may be divided into two principal classes : dust avalanches, and ground avalanches. Dust avalanches generally occur after heavy snowfalls and in still weather, because the snow accumulates on steep slopes until it finally gives way ; first in one place and then in another ; first slowly, then more rapidly, until at last it rushes down with a noise like thunder. The falling mass of snow compresses the air, and makes a violent wind, which often does more mischief than the actual avalanche itself. A great part of the snow rests at the foot of the declivity from which it falls, but a part is caught up by the wind and carried to a considerable distance. Such avalanches fall irregu- larly, as they depend on a variety of circumstances ; IV SNOW AND ICE 59 they cannot therefore be foreseen, and do much damage, often killing even wild animals. Ground avalanches occur generally in spring, when the snow is thawing. The water runs off under the snow, which thus becomes hollow, only touching the ground in places. A slight shock is sufficient to set it in motion, and it tears away down to the ground, which it leaves exposed. Such avalanches depend therefore on the configuration of the surface, and are in conse- quence comparatively regular. In many cases they fol- low the same course year after year. In these tracks, trees cannot grow, but only grass or low bushes. The front part of the avalanche of course first begins to slacken its speed. The part behind then presses on it, and often pushes over it. Those who have been enveloped in an avalanche all agree, that during the motion they could move with comparative freedom, then at the moment of stopping came extreme press- ure, and they found themselves suddenly encased in solid ice. Pressure had caused the particles to freeze suddenly. Avalanches are often looked on as isolated and excep- tional phenomena. This is quite a mistake. They are an important factor in Alpine life. The amount of snow which they bring down is enormous. Coaz ^ esti- mates it in certain districts as equal to 1 metre of snow over the whole district. Without them the higher Alps would be colder, the lower regions hotter and drier. The snow-line would come down lower, many beautiful Alps would be covered with perpetual snow, the glac- iers would increase, the climate become more severe, the mountains less habitable. To appreciate the impor- tance of avalanches one must ascend the mountains on a ^ Die Lawinen in den Schweizeralpen, Bern, 1881. 60 SCENEKY OF SWITZERLAND chap. warm day in spring. From every cliff, in every gorge we hear them thundering down all round us. They descend on all sides like hundreds of waterfalls, some- times in a silver thread, sometimes like a broad cataract. The mountain seems to be shaking off its mantle of snow. However destructive then they may be at times, ava- lanches are on the whole a blessing. ^ Glaciers By the slow action of pressure, and the percolation of water, which freezes as it descends, the firn passes grad- ually into ice. In cool and snowy summers the thick- ness of the layer of firn increases. It is deepest in the higher regions, and thins out gradually, until at length ice appears on the actual surface, and the firn passes into a glacier. Glaciers are in fact rivers of ice, which indeed some- times widen out into lakes. Glacier ice differs con- siderably from firn ice, and the molecular process by which the one passes into the other is not yet thor- oughly understood. Again, if a piece of ice from a lake is melted in warm air the surface gradually lique- fies and the whole remains clear ; on the contrary a piece of compact glacier ice from the deeper part of a glacier if similarly treated behaves very differently ; a number of capillary cracks appear, which become more and more evident, and gradually the ice breaks up into irregular, angular, crystalline fragments. These are known as the " grains du glacier " or " Gletscherkorn," and were first described by Hugi.^ They increase grad- ually in size, but how this growth takes place, and whether they are derived from the granules of the firn, 1 Helm, CHetscherleunde. ^ Das Wesen der Gletscher, 1842; IT SNOW AND ICE 61 is still doubtful. When the firn passes into the glacier they may be about ^ inch across ; in the middle part of a large glacier about the size of a walnut, and at the end 4 or even 6 inches in diameter. Those at the end of the Rhone Glacier vary much in size, but the major- ity are under an inch across. In some cases they are tolerably uniform in size, in others large and small are mixed together. On any clean surface of glacier ice they are easily visible, as for instance in the ice tunnel which is so often cut at the end of glaciers. Their surfaces present a series of fine parallel striae, first noticed by Forel. Glacier ice then may be said to be a granular aggregate of ice crystals. By alternately warming and cooling snow, and saturat- ing it repeatedly with water, Forel found that he pro- duced an ice very similar in structure to that of glaciers. There seems no doubt that this structure considerably facilitates the movements of glaciers.^ Glaciers are generally higher in the middle, and slope down at the two sides owing to "the warmth reflected from the rocks. When the valley runs north and south the two sides are equally affected in this respect ; but when the direction is east to west or west to east the northern side is most inclined because the rocks lie more in the sun, while those to the south are more in the shade. Movement of Glacibks Rendu, afterwards Bishop of Annecy, in 1841 first stated clearly the similarity between the movements of a river and those of a glacier. Subsequent observations have confirmed Rendu's statements. In fact the glacier may be said really to flow, though of course very slowly. I Heim, Oletscherkunde. 62 SCENERY OP SWITZERLAND chap. The movement of a glacier resembles that of a true river, not only generally, but in many details ; the centre moves more quickly than the sides ; where the course curves, the convex half moves more quickly than the concave, and the surface more quickly than the deeper portions. The movement is more rapid, indeed some three times more quick in summer than in vi^inter. The first detailed observations on the movements of glaciers were made independently and almost simul- taneously by Agassiz on the Unter-Aar Glacier, and by Forbes on the Mer de Glace. The yearly motion of the Swiss glaciers is estimated at from 50 to 130, or in some exceptional cases even 300 metres. The rapidity differs however consider- ably, not only in different glaciers, but in different parts of the same glacier ; in different years, and dif- ferent times of year. The remains of Dr. Hamel's guides, who perished in a crevasse on the Grand Pla- teau (Mont Blanc) on 20th August, 1820, were found in 1861 near the lower end of the Glacier des Boissons, having moved 2800 metres in 41 years, or nearly at the rate of 70 metres a year. It has been calculated that a particle of ice would take at least 250 years to descend from the Strahleck to the lower end of the Unter-Aar Glacier ; from the summit of the Jungfrau to the end of the Aletsch Glacier about 600 years. During the middle ages the Swiss glaciers appear on the whole to have been increasing in size, and to have reached a maximum about the year 1820. After that they retreated till about 1840, when they again advanced until 1850-60, since which time they have greatly diminished, though some are now again com- mencing to advance. Those of northern Europe appear IV SNOW AND ICE 63 to be also increasing.^ It is, of course, impossible to make any decided forecast as to the future. Cause op Movement But why do glaciers descend ? Scheuchzer in 1705 suggested that the water in the fissures of the glaciers, freezing there and expanding as it froze, was the power which urged them forwards. Altmann and Griiner in 1760 endeavoured to explain it by supposing that the glaciers slid over their beds ; and no doubt they do so to some extent, but this is quite a subordinate form of movement. Bordier regarded the ice of glaciers "not as a mass entirely rigid and immobile, but as a heap of coagulated matter or as softened wax, flexible and du.ctile to a certain point." This, the "Viscous" theory, was afterwards most ably advocated by Forbes. No doubt the glacier moves as a viscous body would ; but the ice, far from being viscous, is extremely brittle. Crevasses begin as narrow cracks which may be traced for hundreds of yards : a slight difference of inclination of the bed will split the ice from top to bottom. It is, in fact, deficient' in that power of extension, which is of the essence of a viscous substance. The explanation now generally adopted is that which we owe mainly to Tyndall. Faraday in 1850 observed that when two pieces of thawing ice are placed together, they freeze at the point of contact. Most men would have passed over this little observation almost with- out a thought, or with a mere feeling of temporary surprise. Eminent authorities have differed in the explanation of the fact, but into this part of the ques- 1 Heim, Gletscherkimde. 64 SCENERY OF SWITZERLAND chap. tion I need not now enter. Sir Joseph Hooker sug- gested the term " Regelation," by which it is now generally known, and Tyndall has applied it to explain the motion of glaciers. Place a number of fragments of ice in a basin of water, and they will freeze together wherever they touch. Again, a mass of ice placed in a mould and subjected to pressure breaks in pieces, but as the pieces reunite by regelation they assume the form of the mould, and by a suitable mould the ice may be forced to assume any given form. The Alpine valleys are such moulds. When subject to tension, the ice breaks and crevasses are formed, but under pressure it freezes together again, and thus preserves its continuity. Professor Helmholtz in his scientific lectures sums up the question in these words — "I do not doubt that Tyndall has assigned the essential and principal cause of glacier-motion, in referring it to fracture and regela- tion." Heim, however does not regard the problem as being yet by any means solved. ^ He points out that as in the case of water, a large glacier moves under similar conditions more rapidly than a small one. Many bodies will in small dimensions retain their form, which in larger masses would be unable to sup- port their own weight. A small clay figure will stand where a life-sized model will require support. Sealing-wax breaks under tension like ice, but under even slight pressure gradually modifies its form. Prof. Heim is convinced that if a mass of lead, correspond- ing to a glacier, could be placed in a Swiss valley, it would move to a great extent like a glacier. The size of a glacier is therefore an important factor in the question, and throws light on the more rapid movement 1 Heim, Qletscherkunde. IV SNOW AND ICE 65 of tlie greater glaciers, even when the inclination of the bed is but slight. In Heim's opinion then the weight of the ice is sufficient to account for movement, though the character of the movement and the condi- tion of the glacier is due to fracture and regelation. He sums it up in the statement that gravity is the moving force, and the glacier grains the prevailing mechanical units of movement. CeEV ASSES The rigidity of ice is well shown by the existence of crevasses. They may be divided into three classes; — 1. Marginal. 2. Transverse. 3. Longitudinal. The sides of most glaciers are fissured even when the centre is compact. The crevasses do not run in the direction of the glacier, but obliquely to it, enclos- ing an angle of about 45° (Fig. 29, m m) and pointing upwards, giving an impression that the centre of the glacier is left behind by the quicker motion of the sides. This was indeed supposed to be the cause, un- til Agassiz and Forbes proved that, on the contrary, the centre moved most rapidly. Hopkins first showed that the obliquity of the lateral crevasses necessarily followed from the quicker movement of the centre. Tyndall gives the following illustration: — "Let A 0, in the annexed figure, be one side of the glacier, and B D the other ; and let the direction of the motion be that indicated by the arrow. Let S T he & trans- verse slice of the glacier, taken straight across it, say to-day. A few days or weeks hence this slice will have been carried down, and because the centre moves 66 SCENERY OF SWITZERLAND more quickly than the sides it will not remain straight, but will bend into the form S' T' . " Suppose T i to be a small square of the original slice near the side of the glacier. In its new position the square will be distorted to the lozenge-shaped fig- ure T i'. Fix your attention upon the diagonal Ti of the square ; in the lower position this diagonal, if the ice could stretch, would be lengthened to T' i' . But the ice does not stretch, it breaks, and we have a crevasse formed at right angles to T' i'. The mere inspection of the diagram will assure you that the crevasse will point obliquely upward." s- ^ — ^ . I * / > / /■ T T Fig. 27. Marginal crevasses then arise from the movement of the glacier itself ; transverse and longitudinal crevasses are caused by the form of the valley. If the inclination of the bed of a glacier increases, even if the difference be but slight, the ice is strained and, being incapable of extension, breaks across. Each fresh portion as it passes the brow snaps off in turn, and thus we have a succes- sion of transverse crevasses. In some cases these unite with the transverse fissures, thus forming great curved crevasses, stretching right across the glacier, and of course with the convexity upwards. Longitudinal crevasses occur Avherever a glacier issues from a comparatively narrow defile into a wider plain. SNOW AND ICE 67 The difference of inclination checks its descent, it is pushed from behind, and having room to expand, it widens and in doing so longitudinal crevasses are formed. The sides of crevasses are of a brilliant blue, and often look as if they were cut out of a mass of beryl. The mountaineers have a tradition that glaciers will tolerate no impurity, and though this is not of course a correct way of stating the question, as a matter of fact the ice is of great purity. Veined Structure Glacier ice very often looks as if it had been care- fully and regularly raked. It presents innumerable veins or bands of beautifully blue clear ice, running through the general mass, which is rendered whitish Fie. 28. — Section of Icefall, and Glacier below it, showing Origin of Veined Structure. by the presence of innumerable minute air bubbles. The blue plates are more or less lenticular in struct- ure, sometimes a few inches, sometimes many yards, in length, but at length gradually fade away. The whole surface of the glacier in such parts is 68 SCENERY OP SWITZERLAND lined with little grooves and ridges, the more solid blue veins projecting somewhat beyond the whiter ice. This structure is very common, though presenting dif- ferent degrees of perfection in different glaciers, and different parts of the same glacier. It is rendered the more conspicuous, because the fine particles of dirt are naturally blown, and washed into the furrows. The veins are often oblique, in many cases transverse, in some longitudinal, and in others vary in different parts of the glacier. Here also we owe, I think, the true explanation to Tyndall. We will begin with the oblique veins, which are most marked at the sides, and fade away towards the centre of the glacier. Tyndall points out that if a plastic sub- stance, such as mud, be allowed to flow down a sloping canal, the lateral portions, being held back by the sides, will be outstripped by the centre. Now if three circles (Fig. 29) be stamped on the mud-stream, the central one will retain its form, but the two lateral ones will gradually elongate. The shorter axis in m m of each oval is a line of pressure, the longer is a line of strain, consequently along the line m, m, or across the tension, we have, as already explained, the marginal crevasses ; while across the line, or perpendicular to the pressure, we have the veined structure, which is in fact a form of cleavage. Indeed tension and pressure go together, the one acting at right angles to the other. Passing to the cases of transverse veining, we find if we walk up a glacier presenting this structure that we eventually come to an icefall or cascade. At the foot Fig. 29. SNOW AND ICE 69 of the fall the ice is compressed, and this gives rise to transverse veining. Longitudinal veining in the same manner arises when two glaciers meet, as for instance the Talefre and the Lechaud (Fig. 30), where we have transverse pressure and in consequence longitudinal veining. How great must be the pressure in such cases (4 i/^^isfe,^ / J ■/ -Was Fig. 30, — Sketch Map of the Mer de Glace. we can faintly realise if we bear in mind that the glaciers which unite to form the great Gorner Glacier have a width of 5200 metres which is compressed to 1000 and further on to 500 metres. The pressure acts on the ice in two ways. Firstly in the same manner as it produces lamination in rocks ; and secondly by partially liquefying the ice, thus facili- 70 SCENERY OF SWITZERLAND CHAP. tating the escape of the air bubbles which cause its whitish appearance. Liquid Disks The Solar beams also form innumerable liquid disks. As the water occupies less space than the ice, each disk is accompanied by a small vacuum, which shines like silver, and is often taken for an air bubble. DiRTBANDS If we look down on the Mer de Glace we see (Fig. 30) a series of gray, curved, or bent bands, which fol- low each other in succession from Trelaporte down- wards. These " dirtbands " have their origin at the ice cas- cade upon the Glacier du Geant. The glacier is broken at the summit of the icefall (Fig. 28), and descends the declivity in a series of transverse ridges. Dust, etc., gradually accumulates in the hollows, and though the ridges are by degrees melted away and finally dis- appear, the dirt remains, and forms the bands. They are therefore quite superficial. Similar bands occur on other glaciers with ice cascades, and as many as thirty to forty may sometimes be traced. MOTJLINS At night and in winter the glaciers are solemn and silent, but on warm days they are enlivened by innu- merable rills of water. Sooner or later these streams reach a crack, down which they rush, and which they gradually form into a deep shaft. These are known as glacier mills or Moulins. Of course the crack moves down with the glacier, but the same cause produces a IV ~ SNOW AND ICE 71 new crack, so that the process repeats itself over and over again, at approximately the same place. A suc- cession of forsaken Moulins is thus formed. Moulins are often very deep. Desor sounded one on the Fin- ster-Aar Glacier which had a depth of 232 metres. The so-called Giant's caldrons which will be de- scribed further on are sometimes regarded as indica- tions of ancient glacial action. It is probable that in the case of the so-called "glacier garden" at Lucerne this is so ; but as a general rule they were probably formed by river action. In the larger glaciers most of the subglacial rivulets unite under the glacier and flow out at the end in a stream, often under a beautiful blue flat arch generally from 1 to 3 but sometimes even 80 metres in height. In many cases it is possible to enter them for some dis- tance, and galleries are often cut. The ice is a splen- did blue, the surface takes a number of gentle curves, and when the light from outside is reflected from the surfaces, it assumes by complementary action a delicate tint of pink. Moraines ^ The mountain sides which surround glaciers shower down on them fragments, and sometimes immense masses, of rock which gradually accumulate at the sides, and at the end, and are known as "Moraines." When two glaciers meet, a "medial" moraine is formed by the union of two " lateral " moraines (Fig. 80), while the matter carried along under the glacier- is known as "ground Moraine." However many glaciers may unite, the moraines keep themselves distinct, and may 1 The word " Moraine " was adopted by Charpentier from the local name used in the Valais, and has now become general. 72 SCENERY OP SWITZERLAND chap. often be seen for miles stretching up the glacier side by side. Even from a distance we may often see by the coloui that different moraines, and the two sides of a medial moraine, are composed of different rocks. On the Aar glacier the left half of the medial moraine is composed of dark micaceous Gneiss and Mica Schist ; the right half of Avhite Granite. The right lateral moraine of the Puntaiglas glacier, on the south of the Tddi group, is made up of dark greenish Syenite and Granite, the first medial moraine is of titaniferous Syenite, then comes a second of yellowish red Rothidolomite with some Dogger ; then several of bluish black Hochge- birgskalk, and lastly the left moraine is of Puntaiglas Granite, and various sedimentary rocks from Verru- cano to Eocene. 1 The Baltora glacier in the Hindu Kush has no less than fifteen moraines of different colours. The different moraines do not mix ; and frag- ments from one side, even of the same moraine, never pass to the other, but move down with the ice, in the same relative positions. The glacier often rests directly on the solid rock, but in many places there is a layer of clay and stones, to which Ch. Martins gave the name of "ground moraine," and if the underlying rock is examined it will be found to be more or less polished and striated. The importance of the ground moraine was first pointed out by Martins.2 The pressure of the glacier on its bed must be very great. On the Aletsch glacier it has been calculated to be as much as 4 tons to the square decimetre ; under the Arctic glaciers it must be much greater. In the winter of 1844 some poles of timber were dropped under the edge of the Aar glacier: in the 1 Heim, GletscherJninde, p. 348. 2 Hgmie des Veux Mondes, 1847. IV SNOW AND ICE 73 following year they were found to be crushed to small fragments. Blocks of stone are gradually ground down and reduced to glacial mud. This is so fine that it remains a long time in suspension in water, and gives their milky colour to glacial streams. The ground moraine is no doubt formed in some measure from sur- face blocks which have found their way through crevasses, and have to a great extent been crushed and reduced to powder ; but as ground moraines occur under ice-sheets, such as that of Greenland, when there are scarcely any surface blocks, it is clear that the material is partly derived from the underlying bed. At the lower end of the glacier a terminal moraine gradually accumulates, which may reach a height of 50, 100, or even 500 metres. They are more or less curved, encircling the lower end of the glacier. The quantity of debris differs greatly in different glaciers : some, as the Rhone, Turtmann, etc., are com- paratively free, while others^ as the Zinal and the Smutt, have the lower ends almost entirely covered. It is difficult to give the actual number of glaciers in Switzerland, because some observers would rank as sepa- rate glaciers what others would consider as branches, but the number may be taken as between 1500 and 2000. The total area is about 3500 sq. km. The mean inclination of large glaciers is from 5° to 8°, falling however even to less than a degree. The hanging glaciers are much steeper. The greatest thickness of the ice can only be esti- mated. In one place of the Aar glacier Agassiz found a depth of 260 metres without reaching the bottom. From the configuration of the surface however it may safely be calculated that the ice must attain a thickness in places of 400 or even 500 metres. It has been cal- 74 SCENERY OF SWITZERLAND chap. culated that the ice of the Gorner glacier would be enough to build three Londons. The distance to which a glacier descends depends partly on the extent of the collecting ground, partly on the configuration of the surface. The Gorner glacier advances so far on account of the magnitude of the snow- fields above. In 1818 the lower Grindelwald glacier descended to 983 metres above the sea-level. In 1870 it had receded to 1080 metres. The lower limit of the Mer de Glace is 1120 metres. In the Eastern Alps, where the climate is more continental and drier, the general limit is from 1800 to 2300 metres. Ice Tables Small bodies such as pebbles, dust, insects, etc., tend to sink into the ice. On the other hand larger stones intercept the heat. On most glaciers may be seen large stones resting on pillars of ice. These are the so-called Ice Tables. If the stone be wide and flat, the pillar may reach a con- siderable height, for the ice immediately under it, being protected from the rays of the sun, melts less rapidly. The tables are rarely horizontal, but lean to the south, that side being more exposed to the sun. Small stones and sand on the contrary absorb the heat and melt the snow beneath them, unless indeed there is a sufficient thickness of sand, in which case they intercept the heat and form cones, sometimes ten or even twenty feet in height. Medial moraines in the same way tend to check the melting. That on the Aar glacier rises 20, 40, and even 60 metres above the general surface, and from the summit of the Sidelhorn it gives the impression of a wide black wall separating two white rivers. In Green- IV SNOW AND ICE 75 land such ice-walls liave been known to attain a height of 125 metres. We can hardly have a better introduction to the study of glaciers than a visit to the Rhone glacier (Frontispiece). The upper part, which is not shown in the figure, is a magnificent and comparatively smooth ice-field. Then comes a sharp descent, where in a river we should have a cascade or series of cascades, and where the ice breaks into a series of solid waves. The crests gradually melt, and as dust and stones collect in the hollows, and the centre of the glacier moves more rapidly than the sides, we have a succession of dirtbands which curve across the glacier. Below the fall, the bed of the glacier becomes again comparatively flat; the glacier is squeezed out so as to become considerably wider, and as the ice cannot expand, it splits into a number of diverging crevasses. This was much more marked when I first visited the glacier in 1861, and when it was much larger than at present. If we start from the hotel, after crossing the river, at a very short distance we come to a bank, of loose sand and stones, some angular, some rounded, which curves across the valley, except where it has been washed away by the river. This is the moraine of 1820, and shows the line at which the glacier stood for some years. The Swiss glaciers generally increased till about 1820, then diminished for some years, increasing again till about 1855-60, since which they have retreated con- siderably. The moraine of 1856, in the case of the Rhone glacier, forms a well-marked ridge some dis- tance within that of 1820. From that ridge to the foot of the glacier, the valley is occupied by sand and stones in irregular heaps, some of them smoothed and ground by the glacier. This is 76 SCENERY OF SWITZERLAND chap. especially the case with the larger stones, which show a marked difference on their two sides, that turned towards the glacier being smooth, while the lee side is rough and abrupt. Many of the stones were evidently pushed by the glacier along the valley, and have left a furrow behind them. The Rhone wanders more or less over the flat bottom of the valley, and spreads out the material which has been brought down by the glacier. Here and there on the glacial deposits lie blocks with fresh angles, totally different in appearance from the rounded blocks borne by the glacier. These have been brought down by avalanches. Near the glacier are two other small moraines, the outer one that of 1885, the inner of 1893. We know that these moraines were deposited by the glacier, and no one who has seen them can doubt that those farther and farther down the valley have had a similar origin. The Rhone flows from the foot of the glacier in vari- ous and varying streams, but especially at one place near the centre of the face of the glacier, where there is a beautiful blue arch, about 25 metres in height. In 1874 careful measurements were commenced by the Swiss Alpine Club. At first lines of stones were placed annually at the foot of the glacier, but the river washed them away so much that the present limits are laid down annually on a plan. It is found that just as the glacier advances when we have a succession of cold and snowy years, and diminishes when there have been hot and dry periods ; so in each year, even when the glacier is on the whole retreating, it advances in two or three of the winter months. Amongst other means of studying the glacier the Commission have placed lines of stones across it at some distances above the fall. One of these lines was arranged in 1874, the stones painted yellow, and their position carefully marked. When IV SNOW AND ICE 77 they came to the fall they disappeared for four years, after which some of them again emerged at the surface; and some of the central ones have now reached the lower end of the glacier, which has retreated some yards from the spot at which they were deposited. As in many of the most accessible glaciers, a gallery has been cut into the ice, and is well worth a visit. The exquisite curves into which the ice is melted by the eddying currents of air are very lovely. Again one can easily trace the glacier grains, especially if a little ink or other coloured fluid is rubbed over the surface of the ice, when it runs down between the grains, marking them out with dark lines. Each grain, moreover, shows very fine lines of crystallisation, which are parallel in each grain, but differ in different grains. The chief attraction, however, is naturally the splendid blue colour of the ice, and the lovely pink complementary tints of the reflections from the surface. CHAPTER V ON THE FOE.MBE EXTENSION OP GLACISES The present scenery of Switzerland has been much influenced by the former extension of glaciers, and the fertility of the country is greatly enhanced by the mate- rials which they have brought down from the mountains and spread over the low country. Several of the lakes, moreover, which add so much to its beauty, owe their origin to ancient moraines. The existence of a glacial period and the great former extension of the Swiss glaciers is proved by four lines of evidence, namely : — 1. Moraines and fluvio-glacial deposits. 2. Erratic blocks. 3. Polished and striated surfaces. 4. Animal aiid vegetable remains belonging to north- ern species. Glacial Deposits Glacial deposits may be classed under two heads : — 1. Moraines. 2. Glacial deposits which have been rearranged by water and may be termed fluvio-glacial. Moraines are characterised by the presence of polished and striated pebbles, intermixed with more or less angu- 78 FORMER EXTENSION OP GLACIERS 79 lar fragments, often coming from a great distance and yet not rolled, irregularly deposited in sand and mud, which, however, is not stratified. Fluvio-glacial deposits are composed of the same materials, but more or less rolled, and rearranged by r- ■ •"? ^ _^ ^ ^ ^^^^.tt^&ig^rtf i '■ <' -^ 4 ,-*f( ^^p"*^? 3 -# J^^^s** » $' 5 " ^m ^^*-*' « < 4 'mm Wk l^^fl i"^ 1 A-* ^ «/ t''? , ';' Kj^l^^^^^ KV_:,,:;^ ■%f?f ^fSM : "■': '■;'\' ■^" ''■■:;L ^%^K^HB^H^^^ 0^*^^ i ^s^^fcE'''^'' '. - ■'*'' -' ; "- - '■■m^ ~^"'^^w^P Li.-Sli 4.^ 'i^.^^Si?^, j^0 fciD^l:^-'# .>.-^'^^|i i^?' J^^m /^p^g^ -i^^^^ Iti ' Wm ;^ ■"■~S Wn, /-.'.v .. ■^ ,:..^- i^^^fc. %S.'taP^^*'^ I^ll ,:,^ :j>*^^ ^^t^^^^^^^. l:^ r^;--..^ :•■■" - V ' , t"' 'JlK^^^^pS •Tf^,: «*;'-^ .^^., & ■ ' -i*** ■wl^^^^VElK^nV^nlk ^fl * , .... • ^ ''^" ll^9HHH ';.'■- .•*^'.;-v Fig. 31. — View of the Grimsel. water, like river gravels. They are glacial deposits caught up and carried to a greater or less distance by water. These two deposits are in intimate relation; they agree in their composition, and differ only as regards 80 SCEKEEY OP SWITZERLAND CHAP. stratification. The fluvio-glacial beds, as we come nearer and nearer to their source, are composed of larger and more angular pebbles, while the stratifica- 2 tion becomes less and less regular, so that they approxi- mate more and more to the character of true moraine. The surface of a true glacial deposit is irregular, and presents a succession of hills and valleys, often more or less concentric in outline, and enclosing a central de- V FORMER EXTENSION OF GLACIERS 81 pressiou (the site of the glacier itself), so that it forms a sort of amphitheatre. See for instance Fig. 33. The Wettingen Feld in the valley of the Limmat is the cone of fluvio-glacial deposits from the ancient moraine of Killwangen. As glaciers often retreat and then advance again the cone of transition in many cases presents alternations of true morainic and fluvio-glacial strata. When the glacier retreated, the water occupied the central depression between the ice and the moraine, forming a lake. In most cases, however, it cut by de- grees through the moraine, and drained the lake. The Fig. 33. — Glacial Deposits. D, site of ancient glacier ; Z, moraine ; z, fluvio-glacial deposits. streams then wandered over the old glacier bed. That the lake naturally overflowed at the lowest point of the moraine, explains why the outflow is often not in the centre of the valley, and occasionally at some distance from the end of the lake, as, for instance, at the Lake of Hallwyl (Fig. 35). Far down the valleys we find moraines, exactly simi- lar in character to those still being formed along the sides and in front of existing glaciers, and repeated again and again, indicating that glaciers must once have extended far beyond their present areas. The Rhone glacier occupied the Valais, in which are several ancient moraines ; it filled the whole basin of the Lake of Geneva, and the high terrace of St. Paul. Above Evian is a moraine, due to the confluence of the ancient glaciers of the Rhone and Dranse ; so is also the promontory of Yvoire. Still further down 82 SCENERY OF SWITZERLAND chap, v the valley glacial deposits are found along the Rhone as far as, and even beyond Lyons,^ and down the Aar to Waldshut. Fig. 34 represents river terraces and glacial deposits in the valley of the Aar, a short distance above Cob- lenz. Passing from the Aar eastwards, in the district of the Wigger, there are important moraines round the Lake of Wauwyl, which was the site of a Lake Village carefully studied by Col. Suter, but is now drained. In the valley of the Suhr is an important terminal moraine at Stafelbach, another at Triengen, while a Fig. 34. — Section across the Valley of the Aar above Coblenz. Scale, length 1 = 100,000 ; height 1 = 25,000. i, Lower alluvial terrace ; y, upper alluvium covered by moraines and loess; a;, alluvium of the upper plateaux, covered by loess ; j, Jurassic strata in situ. third encircles and has given origin to the Lake of Sempach. In the valley of the Winan there is a terminal mo- raine at Zezv.'il and another just above Miinster. In the valley of the Aa, are three groups ; firstly, oiie south of Lenzburg ; secondly, at the north end of the Lake of Hallwyl are several moraines, Fig. 35 ; thirdly, between Schafisheim and Egliswyl are three moraines, the inner one encircling a moss, marked Tod- tenmoos on the map, through which runs the river Aa. Near Nieder Hallwyl is another semicircular moraine enclosing an area of low ground and the end of the 1 Falsan and Chantre, ies AniAens Glaciers du Bassin du Bhone, 1880. TjUpo. Etching Ca^SCm Fig. 35. — Map of the Country between Lucerne and Aarau. 84 SCENERY OF SWITZERLAND ciiap. lake. The lateral moraine extends along the hill on both sides of the water. The moraines on each side of the water are in parts roughly stratified, and fall away from the lake, having originally sloped no doubt from the great dome of the glacier. In the valley of the Reuss is perhaps the finest group of all, consisting of five ridges forming an amphitheatre round the little town of Mellingen. The Heiterberg between the Reuss and the Limmat is also encircled by one, which reaches a height of no less than 100 metres. In the valley of the Limmat there is a fine terminal moraine at Killwangen, another below Schlieren, a third at Zurich, and a fourth forms the bank which crosses the Lake at Rapperschwyl. These terminal moraines are connected by lateral moraines running along the sides of the hills, but as we shall presently see they do not mark the greatest extension of the glaciers. They mark places where the glaciers made a stand during their final retreat. The moraines on the south of the Alps are even more astonishing. Probably from the steeper slope, and more rapid melting under a southern sun, the ends of the glaciers do not appear to have moved so fre- quently. Hence the terminal moraines are more con- centrated, grander, and higher. They form immense amphitheatres terminating in ridges several hundred feet high, and no one, seeing them for the first time, would for a moment guess their true nature. The blueness of the sky, moreover, the brilliancy of colouring, the variety and richness of the vegetation, give the moraine scenery of Italy an exquisite beauty with which the north can scarcely vie. Each great valley opening on the plain of Lombardy has its own moraine. At the lower end of the Lago Maggiore at Sesto-Calende r FORMER EXTENSION OF GLACIERS 85 are three enormous, concentric moraines. ^ Those of the Lake of Garda are perhaps the largest. They form a series of concentric hills, and attain a height of 300 metres; but those at Ivrea, at the opening of the Val d'Aosta, due to the great glacier proceeding from the south flanks of the Mont Blanc range, are the highest and most imposing. They form an amphitheatre round Ivrea. That on the east, known as the " Serra," runs in nearly a straight line from Andrate to Cavaglio, is twenty miles long, and has a height above the valley of 500 metres. The summit line is very uniform. On the outer or eastern side of the great moraine are several other minor ridges. At the right a similar, but less elevated, moraine stretches from Brosso to Strambinello, but it is not so conspicuous, as it rests against the side of the mountain. From Strambinello to Cavaglio it forms a great semicircle which once probably enclosed a lake, now represented by the Lago di Viverone, Lago di Candia, and some smaller pools. It is nearly bisected by the Dora Baltea. In fact it is characteristic of the Italian valleys that the surface is comparatively low where the valley debouches into the plain, and then gradually rises towards the Po, forming an amphitheatre whose encircling wall is the outer moraine. 2 At several places on the south flank of the Alps, morainic masses are more or less intercalated with younger marine deposits, closely resembling the sub- marine moraines of the Polar regions, and the Boulder Clay of England and Scotland. The older moraines are, moreover, less abrupt, and the slopes are more gentle. 1 Martins and Gastaldi, " Essai sur les terrains sup. de la Vallfie du Po," Bull. Soc. Geol. de France, 1850. 2 Penck, Vergletscherung der Deutschen Alpen. SCENERY OF SWITZERLAND Erratic Blocks The second class of evidence proving the former ex- tension of glaciers is that presented by erratic blocks ; which are often of great size, unrounded, and which have come from a great distance. Several of these are so remarkable that they have struck the imagination of the peasantry, have been attributed to superhuman agency, and have received special names, such as the " Pierres de Niton " in the lake near Geneva, so called from a tradition that in Roman times sacrifices were offered upon them to Neptune. The " Pierre de Crans " near Nyon, is 73 feet long and 20 high. The " Pierre a Bot," near Neuchatel, at a height of 2200 feet, is 62 feet in length, 48 in breadth, and 40 feet high. It is of Protogine and probably came from the St. Bernard. Other celebrated erratic blocks are the "Plough- stone," which rises 60 feet above the ground between Erlenbach and Wetzweil, and contains over 72,000 cubic feet of stone ; the Bloc du Tresor near Orsieres with a cubic content of 100,000 feet; the Monster block at Montet, near Devent, 160,000 ; and the largest of all is, I believe, a mass of Serpentine on the Monte Moro near the Mattmark See, which measures 240,000 cubic feet. These enormous blocks are of course ex- ceptional, but smaller ones are innumerable. In some localities are immense groups — for instance on the hill of Montet, near Devent, at Orsieres in the valley of the Dranse D'Entremont above Martigny, at Arpille on the north side of the valley of the Rhone opposite Martigny, and, still further away from the mountains, the entire south slope of the Jura is strewn with Gran- ite blocks. " Between Moliers, Travers, and Fleurier," V FORMER EXTENSION OP GLACIERS 8Y says De Luc, "there are as many blocks of primitive rock as if one was in the high Alps." ^ One of the most remarkable groups is at Monthey, overlooking the valley of the Rhone below St. Maurice. " We have here," says Forbes, "a belt or band of blocks — poised, as it were, on a mountain side, it may be five hundred feet above the alluvial flat through which the Rhone winds below. This belt has no great vertical height, but extends for miles — yes, for miles along the mountain side, composed of blocks of Granite of thirty, forty, fifty, and sixty feet in the side, not a few, but by hundreds, fantastically balanced on the angles of one another, their gray weather-beaten tops standing out in prominent relief from the verdant slopes of secondary formation on which they rest. For three or four miles there is a path preserving nearly the same level, leading amidst the gnarled stems of ancient chestnut trees which struggle round and among the pile of blocks, which leaves them barely room to grow : so that num- berless combinations of wood and rock are formed where a landscape painter might spend days in study and enjoyment. "2 As already mentioned, these blocks have come from a great distance. No similar rock occurs in the neigh- bourhood, and it is often possible to determine the locality from which they have been derived. For instance, near the Katzensee is a block consist- ing of a peculiar variety of Granite only known to occur at Ponteljes-Tobel above Trons in the valley of the Rhine. Many blocks of the same rock occur on the right bank of the Lake of Ziirich, and they can be fol- lowed all the way to their source. Not one occurs to 1 Agassiz, Essai sur les Glaciers. 2 Forbes, Travels through the Alps of Savoy. 88 SCEKERY OP SWITZERLAND chap. the left of the lake. This could hardly be the case on any other theory than that of transport by a glacier. Again, the " Ploughstone " already mentioned agrees with the fine-grained Melaphyre of the Gandstock in the middle of the Canton of Glarns. The block of Steinhof near Soleure, which measures 65,000 feet, is probably from the Val de Bagnes. The Pierre a Bot, as already mentioned, is of Proto- gine and has come from the St. Bernard. It is probable that the ancient glaciers moved more rapidly than their comparatively diminutive descendants of the present day ; but at the existing rate of move- ment the Pierre a Bot would have taken 1000 years to travel from its original home on the chain of Mont Blanc to its present site near Neuchatel; and the Granite blocks of Seeberg would have spent 2000 years on their long journey. It is evident that these blocks cannot have been brought by water, both on account of the immense ve- locity which would have been required to transport such enormous weights, and because, amongst other reasons, their angles are as a rule sharp and unrounded. Their presence is often attributed by the peasantry to supernatural agency, and many legends grew up round them. Favre^ records a remark made to him by a peasant with reference to a great block of Pro- togine near Sapey. " ' Jamais,' disait-il, " on a vu une si belle pierre : elle est tout entiere, rien de casse. Et puis, elle est si tranquille. On ne salt pas si les pierres grandissent ; mais, il y a 15 ans, je pouvais monter dessus, a present je ne sais comment cela se fait, mais je n'y puis grimper.' " Playfair in 1802 appears to have been the first to 1 Bech. Geol., vol. i. T FORMER EXTENSION OP GLACIERS 89 compare these erratics with moraines, and to suggest that they were transported by glaciers. " For the moving of the large masses of rock," says Prof. Playfair,^ "the most powerful agents without doubt which nature employs are the glaciers, those lakes or rivers of ice which are formed in the highest valleys of the Alps, and other mountains of the first order. These great masses are in perpetual motion, together with the innumerable fragments of rock with which they are loaded. These fragments they gradu- ally transport to their utmost boundaries, where a formidable wall ascertains the magnitude, and attests the force, of the great engine by which it was erected." The immense quantity and size of the rocks thus trans- ported have been remarked with astonishment by every observer. Perraudin, a Chamois hunter of the Val de Bagnes, subsequently but independently made the same suggestion to Charpentier. It also occurred to and was proposed in more detail by Venetz, and at length in 1829 worked out by Charpentier with masterly ability. Agassiz compared the Swiss phenomena with those pre- sented in the north of Europe, and showed that in both cases the country was covered by a sea of ice, from which the highest summits alone emerged. Charpentier 2 and subsequently Guyot^ traced the course of the erratic blocks and pointed out that as we proceed from the place of origin they spread as it were in a fan, and that those from one district do not over- lap those from another, as would be the case if they had been distributed by rivers or icebergs : for instance those of the West Jura come from Mont Blanc, and from the Valais, those of the Bernese Jura from the 1 Illustrations of the Huttonian Theory, vol. 1. 2 Essai sur les Glaciers. 3 Bull. SoG. Sci. Nat. NeucJicltel, vol. i. 90 SCENERY OF SWITZERLAND chap. Bernese Oberland, and those of Argovie from the east- ern cantons and the Rhine. ^ Not only are the blocks from each drainage area kept separate, but even as a rule those from the two sides of the same valley. I say as a rule because in some few cases the glaciers appear to have varied in relative dimensions, one encroaching for a time on another, and in its turn being driven back. This however only applies to some few exceptional areas, as for instance between the glaciers of the Linth and the Reuss. Again, the erratic blocks are specially numerous on the summits and slopes of hills, much more than in val- leys : they are not sorted in sizes, but even the largest are found perhaps 50, or even 100, miles from their original site. The smaller blocks are often polished and striated, like those on existing glaciers. For these and other reasons there can be no doubt that they have been carried by glaciers to their present position. These great blocks, however, imposing as they are, are yet as nothing to the mass of gravel, sand, and mud brought down by the glaciers, carried over intervening ridges and across lakes, and spread over the whole of Switzerland. The erratic blocks are unfortunately rapidly disap- pearing, as they are much in demand for building and other purposes. Some of the most remarkable have, however, happily been secured, and will be preserved by the Swiss Scientific Societies. Considering the immense magnitude of the moraines and the enormous number of erratic blocks, it is evi- dent that the glacial period must have been of very long duration. 1 Agassiz, iStudes sur les Glaciers. v former extension of glaciers 91 Polished and Striated Surfaces — Roches Moutonnbes A third class of evidence is that furnished by pol- ished and scratched rock surfaces, which of course are best preserved when the material is hardest. The rocks are sometimes polished like a looking-glass. Such sur- faces occur under and round existing glaciers, where there can be no doubt that they are the work of the ice, or rather of the stones contained in it. Fig. 31 is a photograph of the Hospice of the Grimsel, showing a remarkable case of such glaciated rocks. Similar sur- FiG. 36. — Diagram oi Crag and Tail. faces occur, however, far away from the present glaciers and even in countries where none exist. The gray rounded bosses (Fig. 31) were termed by De Saussure " Roches Moutonnees," from their frizzled surface. The term has been generally adopted, mainly perhaps be- cause at a distance they look not unlike sheep's backs. Smooth rock surfaces may often be seen at the sides of valleys, sometimes at a great height — many hundred or even some thousands of feet above the present river, and far away from the present glaciers, as, for instance, on the slopes of the Jura. They are specially well developed where from a turn in the valley, or any other cause, the ice met with most resistance. The rocks at Martigny are a very fine example. They do not, however, generally rise to the upper- most ridges, which have therefore (Fig. 37) quite a different character. 92 SCENEEY OF SWITZERLAISD De Saussure first noticed the prevalence in the Alps of smooth and even polished rock surfaces, but he did not suggest any explanation. Charpentier pointed out that they were due to the action of glaciers. Running water also smooths rocks, but it is almost always easy to distinguish the action of water from that of ice. In the first place the " Roches Moutonn^es " are generally marked by striae, running in the direction of the valley, and due to small stones contained in the ice and frozen earth. Again water acts most energetically in the hol- lows, ice especially on any projecting surface, so that in Brunt. rSti.J»=r ^>•^'• Fig. 37. — View of the Brunberghorner and the JueUistock, near the Grimsel, showing the Upper Limit of Glacial Action. water-worn surfaces the curves are concave, while on " Roches Moutonnees " they are convex. The action of water is also much more irregular than that due to ice. De Saussure was also long ago struck by the fact that at Chamouni, in the valley of the Aar, and elsewhere, the higher rocks were angular and pointed, while the sides of the valley below were rounded and smooth, but he did not suggest any explanation. Hugi ob- served the same fact, and attributed it to a difference in the character of the rocks. Desor,^ however, in 1841 ascended the Juchliberg, where the contrast is ^ Desor, Gebirgsbau. V POEMER EXTENSION OF GLACIERS 93 well marked, and satisfied himself that the Granite was absolutely the same. He observed moreover, that on the smooth Granite, especially on the upper part, were many blocks of Gneiss, brought from the Mieselen and the Ewigschneehorn. These blocks could only have been brought by glaciers, and he concluded, therefore, that the smooth polished surfaces were due to the ac- tion of the glacier, and that the rough angular upper parts were those which had stood above the level of the ice. Such polished surfaces are by no means confined to the Alpine valleys. Where suitable rocks occur, they are found throughout the Central plain and on the Jura, when they are often very well developed, and known locally as Laves. The upper level of the rounded rocks falls with the valley. On the shores of Norway and Sweden such glaciated surfaces can even be traced under the sea, especially when the water is free from sand. The scratches fol- low the general direction of the valley, the polished surfaces are on the weather side, and the lee side is the most abrupt, as in Fig. 36. A good example of such smoothed rocks may be seen just in front of the great hotel at the Maloja. Giants' Caldrons Giants' caldrons are sometimes assumed to be evidence of ancient glacier action. Those at Lucerne and at the Maloja probably are so, but in other cases similar hol- lows have been produced by river action. Evidence derived prom the Flora and Fauna Another class of evidence is that derived from botany and zoology. Many of the plants now occupying the 94 SCENERY OF SWITZERLAND chap. Swiss mountains are indigenous to the Arctic regions. They could not under existing circiimstances cross the intervening plains, but must have occupied them when the climate was colder than it is now, and been driven up into the mountains, like the Marmot and the Cham- ois, as the temperature rose. The Arctic willows, the Larch, and AroUa pine for instance, are Siberian species, and do not occur in Germany. Here and there also in the drift and the peat-mosses of the lowlands remains have been found of Alpine and Arctic species — the AroUa pine. Dwarf birch (Betula nana), Arctic willows (Salix polaris, Salix retusa, and Salix reticulata), Dryas, Polygonum viviparum, etc. Moreover, we find living colonies of high Alpine spe- cies, the seeds of which can scarcely have been carried by wind, on elevated summits in the lower districts, and in the marshes behind ancient moraines. They cannot have been brought by water, because they occur in some districts not watered by Alpine streams. On the Uetli- berg Prof. Heer found two plants which especially char- acterise moraines, the Alpine toad flax, and a willow-herb (Epilobium Fleischeri). An Alpine fern (Asplenium septentrionale) which is said to be found nowhere else in the Canton of Ziirich, occurs on the Ploughstone of Erlenbach. There are two Swiss species of Rhododen- dron ; one with the under surface of the leaves rusty (R. ferrugineum), the other with fringed leaves (R. hirsutum). This latter species prefers a limestone soil and lower regions, so that we should expect to find it prevalent on the Jura. Yet the rusty-leaved species alone occurs there, having probably been brought by the ancient glacier from the Crystalline mountains of the Simplon and St. Bernard, where it is very abundant.^ 1 Heer, Priirueval World of Switzerland, vol. ii. V FORMER EXTENSION OP GLACIERS 95 The animal kingdom also affords us similar evidence. We find living colonies of Alpine and Arctic animals, especially Insects and Molluscs, on the summits of iso- lated mountains and in the marshes behind moraines, in association with Alpine plants and erratic blocks. Moreover, just as land animals have retired up the mountains, so have aquatic species been driven into deeper and colder vi^aters — Nephrops norvegicus, for instance, into the depths of the sea at Quarnero, sev- eral arctic animals into the deep waters of the Swiss lakes Wenern and Wettern. In the glacial deposits remains of various Arctic species have been met with. In the gravel-beds near Maidenhead, Charles Kingsley and I found a skull of the Musk Sheep, and remains of the same species, though rare, have since been met with in other parts of Europe. With the -Musk Sheep, the Urus, the Aurochs, the Wild Horse, the Mammoth, Hairy Rhinoceros, Reindeer, Elk, the Giant Stag or Irish Elk, Glutton, Ibex, Chamois, Cave Hysena, Cave Bear, Polar Fox, Lemming, Ptarmigan, Marmot, Snowy Owl, etc., have been also found in glacial deposits, though fossil remains are rare in the Swiss deposits of this age. It would be out of place in the present volume to enter into the consideration of the causes which prob- ably led to the existence of the glacial period, or to its probable date. I have in another work (^Prehistoric Times) discussed this question and see no sufficient reason to change the opinion (though doubts have recently been thrown on it by Sir H. Howorth and others), that it was mainly due to astronomical causes, and reached its maximum from 50 to 100,000 years ago. If this explanation be correct it follows that periods of cold and warmth must have followed one another 96 SCENERY OP SWITZERLAND chap. more than once, at intervals of 21,000 years. And in accordance with this we find, as Morlot long ago pointed out, that the glaciers have advanced and retreated more than once. Beds indicating warmer conditions are interposed between glacial deposits, and the Swiss and South German geologists believe that there were three peri- ods of cold with milder intervals. In Scotland James Geikie and others have brought forward evidence of more numerous oscillations.^ Morlot was primarily led to this conclusion by his observations in the valley of the Dranse, south of Thonon on the Lake of Geneva, which I had the pleas- ure of visiting under his guidance. In this gorge between two well-marked glacial deposits is a deposit indicating a milder climate. Again at several places in the Canton of Ziirich are beds of lignite, sufficiently thick to have been worked for fuel. They are intercalated between glacial depos- its. They indicate a luxuriant vegetation and conse- quently a mild climate; they contain moreover remains of animals, such as the hippopotamus, which could not support great cold. This can only be accounted for, I think, by assuming that these groups of animals occu- pied the country alternately. Moraines which have been long exposed to the at- mosphere become gradually modified at the surface. The pebbles are much weathered and sometimes quite disintegrated, even those of Granite crumbling into a sort of clay while retaining their original form. The layer affected may have a thickness of one to two feet or even more. This weathered crust often assumes a reddish colour, whence it is called by Italian geologists "Ferretto." ^ The Great Ice Age. V FORMEE EXTENSION OF GLACIERS 97 Where an old moraine lias after a long interval been covered by a later one, the Ferretto enables us to dis- tinguish between the two. It is in fact a strong con- firmation of the existence of inter-glacial periods, during which the glaciers retreated, and a more genial climate prevailed. At Ivrea, for instance, the presence of Ferretto shows that the gigantic moraine known as the Serra was not formed during one long continuous glaciation. The moraines which are coated with Fer- retto occupy as a rule the outer side of the morainic amphitheatre, and are covered on their inner edges by the later and inner moraines. Lignite beds also occur on the south of the Alps.^ One of the places where an inter-glacial period is most clearly shown is in the val- ley of the Inn. At Hottingen, close to Innsbruck, is a great fluvio-glacial deposit, reposing on a ground moraine at a height of 1300 metres above the bottom of the valley, and capped to a height of 1900 metres by another. In these fluvio-glacial beds forty-one species of plants have been found and studied by M. Wett- stein. Of these twenty -nine now live in the immedi- ate neighbourhood, six in the Tyrol, but at a lower level, six further south, and four have not been deter- mined. Here then we have evidence that the valley of the Inn was (firstly) filled by a glacier to the height of 1300 metres, (secondly) that then followed a period with a climate somewhat milder than the present, suc- ceeded (thirdly) by another glacial period, during Avhich the valley was again filled by ice to a depth of 1900 metres.2 The first Swiss ice age is represented by ground moraine, and by " Deckenschotter " ; a diluvial gravel, 1 Kiitimeyer, ijber Pliocene und Eisperiode auf beiden Seiten der Alpen. ^ Penck, Vergletscherung der Deutsohen Alpen. H 98 SCENERY OF SWITZERLAND chap. curiously characterised by the presence of rounded hollows. These were formerly occupied by pebbles, which have been dissolved and washed away through the hard but permeable matrix. As this was the period of greatest glaciation, and with the exception of one or two heights, as for instance, the Napf, there is, on the whole of the Central plain between the Jura and the Rhine, no considerable area where traces of former glacial action are not to be met with. They attain in places a great thickness, sometimes even more than 400 metres. It seems at first therefore remarkable that no ter- minal moraines are known which can be referred to this period. But it must be remembered that the whole country was covered by ice, with the exception of the very highest parts. Hence, no doubt, as is the case in Greenland now, the surface of the ice was very free from debris, and hence, perhaps, the periph- eral glacial deposits are only represented by ground moraine. The second ice age is represented by the moraines high up on the hills overlooking the valleys ; and the third by moraines which form more or less complete ridges curving across the valleys, and along the slopes. It is possible that the glaciers may in some cases have been pushed forwards again over the inner moraines. At Hallwyl, for instance, the moraine immediately en- circling the lake is very flat, which Dr. Miihlberg thinks may be thus accounted for. Limits of the Ancient Glaciers The evidence seems then conclusive that the glaciers were once far larger than at present, and the facts already summarised give some indication of the extent. V FORMER EXTENSION OP GLACIERS 99 Beginning with the Rhone glacier, the former upper limit of the ice at Oberwald was 2766 metres, or 1400 above the river ; ^ at Viesch it was 2700, or 1700 above the river ; at Leuk 2100, or 1470 above the river ; at Martigny 2080, or 1620 ; at Geneva 1300, or 950 metres above the lake.^ On the slopes of the Jura it rises highest at Chasseron, north-west of Neuchatel, opposite the valley of the Rhone, where it attains an elevation of over 1350 metres, or 977 above the lake, descending gradually to the plain on one side at Soleure, on the other at Gex. At Neuchatel, the erratic blocks form a band about 800 feet above the lake. Above and below that line they rapidly diminish in number. The Rhone glacier, then, at the period of its greatest extension,^ not only occupied the whole Valais and the Lake of Geneva, but rising on the Jura to a height of 1350 metres, crossed the Vuache, descended into the present Rhone valley, sweeping round by Bourg, Tre- voux, Lyons, and Vienne on one side, sent a wing beyond Pontarlier as far as Salins and Ornans, and ex- tended down the valley of the Aar as far as Waldshut, almost meeting the western extremity of the glacier of the Rhine. The ancient glacier of the Rhine occupied the Lake of Walen, the whole valley of the Thiir as far as Schaff- hausen, the Klettgau, and almost to Waldshut, filled up the Lake of Constance, extending considerably to the north down the Danube as far as Sigraaringen, and for some distance its northern end follows the present watershed between the regions of the Rhine and the Danube. 1 Falsan and Chantre, Anc. Glaciers du V. du Mhone, vol. ii. 2 Favre, Description Gcol. du Canton de Geneve, vol. i. 3 See Favre, Carte des Anciens Glaciers de la Suisse. 100 SCENERY OF SWITZERLAND chap. Thus the two great glaciers of the Rhone and the Rhine almost enclosed those of the Aar, the Reuss, and the Limmat. That of the Aar extended as far as Berne, where there is a very fine moraine. The glacier of the Reuss extended to Aarau, and down the valley of the Aar to Coblenz. On the east it filled the Lakes of Egeri and Zug, extended along the Albis to the Uetliberg, and to Schlieren on the Limmat, following the valley down to Coblenz. The glacier of the Limmat was bounded on the west by that of the Reuss ; on the east from Wesen on the Lake of Walen, to the Rhine at Eglisau, following the valley to Coblenz, where therefore these four great glaciers met. The glaciers of the Mont Blanc range not only fiUed the valley of Chamouni and the country to the west as far as and beyond the Lake of Bourget, but flowed over to the east and joined that of the Rhone. In fact a sea of ice covered the whole country, with the exception of some mountain tops, from Lyons to Basle, along the Rhine and the Lake of Constance across Bavaria, extending to Munich and beyond Salz- burg. The extension of the glaciers does not, however, necessarily imply any very extreme climate. Paradoxical as it may appear, glaciers require heat as well as cold : heat to create the vapour, which again condenses as snow. A succession of damp summers would do more to enlarge the glaciers than a series of cold seasons. Leblanc ^ estimated that the glacial period need not have had an average temperature of more than 7 ° centigrade below the present, and other great authorities consider that at any rate a fall of even 5 ° would suffice. 1 Bull. Soo. Geol. France, 1843. T FORMER EXTENSION OF GLACIERS 101 The temperature decreases 1° for about every 188 metres. A fall of 5° would = 940 metres. The pres- ent snow line being 2700 metres, would descend to 1760 metres, and the lower limit of the glaciers from 1200 metres to 360 or somewhat below Geneva, the level of which is 375. It would indeed be even lower, because the greater the snowfield the further the glacier descends. We have no evidence of the existence of Man in pre- glacial times, and whether he inhabited Switzerland during the inter-glacial period is still uncertain. Riiti- meyer has described certain pieces of wood belonging to that period, which have been cut by some sharp in- strument, and which are so arranged as to form a sort of basket work. They certainly appear to be due to human workmanship, but the evidence is not altogether conclusive. It has happened no doubt to many of us to stand on some mountain top when the surrounding summits have been covered with snow, and the intervening val- leys have been filled with a thick white mist, which, especially in the early morning light, can hardly be distinguished from snow. In such a case, we have be- fore us a scene closely resembling that which the coun- try must have presented while it was enveloped by the ice of the glacial period. The geologists of Bavaria have brought forward strong evidence for the belief that in Bavaria and Swabia there were three periods of great extension of the glaciers with intervals of a milder climate ; and Dr. Du Pasquier, who has especially studied the fluvio- glacial deposits of Switzerland, considers that they confirm this view. The first cold period is, he considers, represented by the so-called " Deckenschotter," of which perhaps the best-known example is that on the summit of the Uetli- 102 SCENBEY OP SWITZERLAND chap. berg near Zurich, at a height of 400 metres above the lake. It is a coarse gravel, more or less cemented to- gether, and in which many of the pebbles have perished and disappeared, leaving rounded cavities. ^ This de- posit originally formed a more or less continuous sheet, from 30 to 50 metres in thickness, deposited by the water flowing from the melting glaciers, but has been to a great extent removed, fragments only remaining here and there on the high ground. It is remarkable that it contains no traces of Julier or Puntaiglas Gran- ite,2 probably because these rocks were still covered by the Crystalline schists. The lateral moraines of this period are unknown, but the ground moraines are sometimes well developed. Under the Deckenschotter on the Uetliberg they attain a thickness of 2 to 20 metres. They were probably for the most part de- stroyed by the greater subsequent extension of the glaciers during the second ice age. The second ice age is regarded as having been the most intense : it is represented by gravel-beds, still far above the present valleys, though at a lower level, and by outer and upper moraines, as for" instance in the Ziirich district those of Hongg, of the Albis, etc. The terminal moraines of this period were however probably beyond the boundaries of Switzerland. The thii-d ice age is indicated by the lower terraces and the moraines in the valleys. In that of Zurich, the Mo- raine of Killwangen was probably the outer one, while those of Ziirich and Rapperschwyl represented long periods of arrest and standstill of the glaciers during their general retreat. In theory this explanation is clear and simple, but it 1 This structure does not occur in the true Nagelflue. ^ Du Pasquier, Beitr. z. Geol. K. d. Schw., L. xxxi. V FORMER EXTENSION OF GLACIERS 103 is not always easy to identify the beds. The " Decken- schotter," or upper and older bed, can indeed be gen- erally recognised by the numerous cavities, the "rotten" condition of many of the pebbles, by its being much more frequently cemented together, and in some dis- tricts by the nature of the pebbles ; in the Ziirich val- ley, for instance, by the absence or great scarcity of Sernifite and of the Alpine siliceous rocks, and by the frequency of Hochgebirgskalk, which does not occur in the Miocene Nagelflue ; ^ but there are many glacial deposits the exact age of which is very uncertain. The following table gives the periods, the deposits, and the great characteristic Mammalia, according to Dr. Du Pasquier.^ The Glacial periods were in general, in Dr. Du Pas- quier's opinion, so far as the central Swiss valleys were concerned, periods of deposit, the inter-glacial, periods of excavation. 1 Aeppli, Beitr. z. Geol. K. d. Schw., L. xxxiv. ^Beitr. z. Geol. K. d. Schw., L. xxxi. 104 SCBNEKY OF SWITZERLAND Corresponding Deposits in England. .3 1 > ■a 1 O 1 X 3 s a Pi o s < o Mammoth (Elephas primigenius). Rhinoceros tichorhinus. Elephas antiquus. Rhinoceros Merckii. Hippopotamus major. 03 ■E.i Hi a Elephas meridionalis. Mastodon arvernensis. H O a R Inner Moraines. Lower Terrace grands. -i O o o Outer Moraines. High Terrace gravels. o 1 1 P < o o s « M P-l O Pi a> .2 0) Pi i o s- c S .1 tP 1 o Hi CD s § 1 2§ S S as i Ph ■a 1 3 3 ■3 1 S.2 o 02 -3 ;gPH ■3 1 a S bo c o Hi '6 o I ■3 "i 3 g CHAPTER VI VALLEYS Valleys and rivers are so closely associated with one another, that we generally think of them as insep- arably connected ; and indeed there are but few valleys which have not been deepened and profoundly modified by the action of water. Nevertheless many valleys are " teetonic," that is to say, they are due, or stand in a definite relation, to geo- logical structure ; and there are some details of valley modelling, which are independent of water action, and which it may be convenient to consider separately. As already mentioned the plain of Lombardy is a val- ley of subsidence, the lower limb, as it were, of the great arch of the Alps. It has not been excavated by the Po; on the contrary that river has been for ages occupied in filling it up, and at Milan a boring was sunk 162 metres, without reaching the bottom of the river deposits.^ The valley of the Rhine below Basle is also a line of subsidence, and the two Crystalline regions of the Black Forest and the Vosges were once continuous. Valleys belong to several different classes, and in Switzerland have received special names, such as Vals, Combes, Cluses (Clausa, closed), Ruz, Cirques, etc., which, however, do not cover all the different kinds, and are not always used in the same sense. In many cases valleys follow the " strike " or direc- 1 Penck, Morphologie der Erde, vol. ii. 105 106 SCENERY OF SWITZERLAND tion of the strata, in which case they are termed, as first suggested by De Saussure, longitudinal vaUeys ; while in others they cut across the strata and are known as transverse or cross valleys, or cluses. Longitudinal valleys again, as Escher von der Linth first pointed out, are of three distinct kinds. Synclinal valleys (see ante, p. 35) occupy the de- pressions of folded strata. Many of the Jura valleys belong to this class. They are generally broad. A' Fig. 38. Anticlinal valleys are those which arise when the arch between two synclinals is broken, and the action of water being thus facilitated, a valley is formed, as for instance that of Tiniere (see p. 239), which opens on the Lake of Geneva at Villeneuve. In both these classes the strata are the same on the two sides of the valley. A third class of longitudinal valleys is due to the outcrop of layers of different hardness. In such cases the strata on the two sides are dis- similar; such valleys are known in Switzerland as " Combes. "1 Suppose a fractured anticlinal (AA'A", Fig. 38) has iln this country the word " Combe " is often used as synonymous with "Cirque." VALLEYS 107 Fig. 39. been lowered by denudation to J. C" J.", and is drained by a stream running from C to E. If the strata are of different degrees of hardness, a soft stratum BB'B" between two harder ones A and O will here and there be brought to the surface. In such a case, owing to the greater softness of the stratum B, secondary streams will often cut their way back as in Fig. 39, FF, thus forming longitudinal valleys parallel to the ridge, the sides being formed by the harder strata AO. Such valleys (Fig. 40) are common in the Jura. Sometimes there may be two or even three such " Combes " along a main valley, as for instance (Fig. 41) between Mont Tendre and the valley of the Orbe, where we have four ridges of harder strata, Urgonian, Neocomian, Valangian, and finally Portland rock en- closing three combes due to the existence of softer layers. It is obvious that in this case the transverse valley BE (Jig. 39) is older than the longitudinal valley ^J^. A glance at any geolog- ical map of Switzerland will show that many rivers run along the boundary, that is at the outcrop, of strata. On the other hand the long lines of escarpment which stretch for miles across country, and were long supposed Fig. 40. 108 SCENERY OF SWITZERLAND to be ancient coast lines, are now ascertained, mainly by the researches of Whitaker, to be due to the differ- ential action of subaerial causes. The Chalk escarp- ments in our own country and the great wall of the Bernese Oberland are of this character. That the lon- gitudinal valleys owe their origin to the same cause as the mountain chains, may safely be inferred from the fact that they follow the same direction. They are in fact negative mountain chains. Fig. 41. — Section from the Valley ol the Orbe to Mount Tendre. Transverse Valleys Transverse valleys cross the strata more or less at right angles. They are generally narrow, and often form deep gorges, more or less encumbered by fallen rock, and the harder the rock the narrower the valley. Their character is greatly influenced by the nature of the strata, their inclination, and whether the fall coin- cides with, or is in opposition to, that of the beds. Unless, however, the fall of the ground coincides exactly with that of the strata, a river running along a transverse valley will generally cross here and there harder layers which give rise to cataracts or waterfalls. When the strata are horizontal the action of running water is comparatively slow. Steeply inclined or ver- tical strata on the other hand greatly facilitate erosion. VI VALLEYS 109 Not only does the force of gravity take part in the labour, but the water sinks in more easily, and both chemical and mechanical disintegration is thus much increased. Hence it is that while cross valleys often drain longi- tudinal valleys, the reverse seldom happens. Cross val- leys in fact dominate longitudinal valleys. Another respect in which, so far as Switzerland is concerned, the longitudinal differ from the transverse valleys, is that the former run approximately east to west, the latter north to south. This makes a great difference in their general aspect. In the transverse valleys not only do the two sides consist of similar rocks, but both receive approximately the same amount of light and sunshine, so that the vegetation grows under more or less similar conditions. In the longitudinal valleys, on the contrary, not only are the strata often different on the twd sides, but the northern side, which looks to the south, receives more sun, while the southern side is more in shadow. The contrast is strongly shown in the Valais itself, where the south side is green and well wooded, the north on the contrary comparatively dry and bare. In some places, for instance in the valley of the Rhone below Visp, the green lines of vegetation which follow the "Bisses" or artificial water-courses are very conspicuous. On the Lake of Ziirich, though the vegetation is the same on both sides — woods and meadows and vine- yards — the distribution is quite different. Both sides of the lake are terraced, so that we have flat zones and steep slopes. On the north-east side the slopes get more sun, and hence the vines are planted on them, while the meadows and woods are on the terraces. On the west, however, the terraces get more sun and conse- 110 SCENEEY OF SWITZERLAND chap. quently the vines are on the terraces and the meadows and woods on the slopes. There is another class of valleys, namely, those which are due to lines of fracture or dislocation, and which may be termed fault- valleys. They are, however, com- paratively rare. One and the same river may be of a very different character in different parts of its course. It may run at one place in a longitudinal, at another in a trans- verse, valley. The Rhone, for instance, occupies a transverse valley from the glacier nearly to Oberwald, a longitudinal valley from Oberwald to Martigny, and a cross valley from Martigny to the lake. If we look at an ordinary map of Switzerland, we can at first sight trace but little connection between the river courses and the mountain chains. If, however, the map is coloured geologically, we see at once that the strata run approximately from S.W. to N.E. and that the rivers fall into two groups running either in the same line or in one at right angles to it. The central mountains are mainly composed of Gneiss, Granite, and Crystalline schists ; the line of junction between these rocks and the Secondary and Tertiary strata on the north, runs, speaking roughly, from Hyeres to Grenoble, and then by Albertville, Sion, Chur, Inns- bruck, Radstadt, and Hiefiau, towards Vienna. This line is followed (in some parts of their course) by the Isere, the Rhone, the Reuss, the Rhine, the Inn, and the Enns. One of the great folds shortly described in the preceding chapter runs up the Isere, along the Chamouni valley, up the Rhone, through the Urseren Thai, down the Rhine valley to Chur, along the Inn nearly to Kufstein, and for some distance along the Enns. Thus, then, fi^■e great rivers have taken advan- tage of this main fold, each of them eventually break- VALLEYS 111 ing through into a transverse valley. The origin of the valley is therefore not clue to the rivers running through it. The Puster- thal in the Tyrol offers us an in- teresting case of what is obvi- ously a single valley, slightly raised, however, in the centre, near Toblach, so that from this point the water flows in opposite directions — the Drau eastward, and the Rienz westward. In this case the ele- vation is single and slight : in the main valley of Switzerland there are sev- eral watersheds, and they are much loftier ; still we may, I think, regard that of the Arve (see Fig. 42) from Les Houches to the Col de Balme, of the Rhone from Martigny to its source, of the Urseren Thai, of the Vorder Rhine from its source to 112 SCENBEY OF SWITZERLAND chap. Chur, of the Inn from Landeck to below Innsbruck, even perhaps of the Enns from Radstadt to Hiefiau, as in one sense a single valley, due to one of these longi- tudinal folds, but interrupted by bosses of Gneiss and Granite — one culminating in Mont Blanc, and another in the St. Gotthard — which have separated the waters of the Isere, the Rhone, the Vorder Rhine, the Inn, and the Enns. That the valley of Chamouni, the Valais, the Urseren Thai, and the Vorder Rhine really form part of one great fold is further shown by the presence of a belt of Jurassic strata nipped in, as it were, be- tween the Crystalline rocks. This great valley then, though immensely deepened and widened by erosion, cannot owe its origin or direc- tion to river action, because it is occupied in different parts by different rivers running in opposite directions. We have in fact one great valley, but several rivers. It is therefore due to one original cause; it is,- to use a technical term, " geotectonic," and is due to the great lateral compression from S.E. to N.W. which has thrown Switzerland into a succession of great folds. A similar case is that of the Val Ferret. The depth is no doubt mainly due to erosion, but it follows the tract of Jurassic strata which lies at the foot of the great mountain wall of the Mont Blanc range. No one who looks at the map can for an instant doubt that it is in reality a single valley ; but it falls into three parts — the eastern portion is occupied by a branch of the Dranse running to the N.E. ; the centre by the Doire running S.W., and the west by another branch of the Doire running N.E., the two, meeting at the foot of the Glacier de la Brenva, fall into a transverse valley and run S.E. towards Courmayeur and Aosta. Again the great valley which has given rise to the Lakes of Neu- chatel and Bienne, and which follows the course of the "" VALLEYS 113 Aar from Soleure to Brugg, reappears in the course of the Danube below Donaueschingen. In some respects the courses of the rivers indicate the original configuration of the surface even better than the mountains. Many rivers, after running for some distance along the strike (see p. 32) of the strata, change their direc- tion, not turning in a grand curve, but suddenly break- ing away at right angles, as for instance the Rhone at Martigny, the Aar near Brugg, the Rhine near Chur, the Inn near Kufstein. But why should the rivers, after running for a cer- tain distance in the direction of the main axis, so often break away into cross valleys ? The explanation usu- ally given is that transverse streams have cut their way back, and thus tapped the valley. This is no doubt true in some cases, but cannot be accepted, I think, as a general explanation. Prof. Bonney ^ called attention to this tendency in his second lecture on the " Growth and Sculpture of the Alps." "On considering," he says, "the general disposition of the rocks constituting the Alpine chain, we perceive that, in addition to the long curving folda which determine the general direction of the component ranges, they give indications of a cross folding. The axes of these minor undulations run from about N.N.E. to S.S.W." He suggests three possible explanations : — (1) " that the Alps are the consequence of a series of independent movements, not simultaneous, so that the chain results from the accretion laterally of an independent series of wave-like uplifts ; (2) that the chain was defined in its general outline by a series of thrusts proceeding out- ^ Alpine Journal, Nov. 1888. 114 SCENERY OF SWITZERLAND chap. ward from the basin of the North Italian plain, and afterwards folded transversely by a new set of thrusts acting at right angles to a N.N.E. line; (3) that the transverse disturbances are the older, and that the floor on which the Secondary deposits were laid down had already been disposed in parallel folds, trending roughly in the above direction." He adopts the third hypothesis. He considers that the transverse wrinkles were perhaps Triassic, " not im- probably post-Carboniferous," and therefore far older than the main longitudinal folds. "Still," he con- tinues, " though I incline to this view, the question is so complicated that I do not feel justified in expressing a strong opinion, and rather throw out the idea for consideration than press it for acceptance. All that I will say is that T find it impossible to explain the exist- ing structure of the Alps by a single connected series of earth movements." Under these circumstances I have ventured ^ to make the following suggestion. If the elevation of the Swiss mountains be due to cooling and contraction leading to subsidence as suggested in p. 26, it is evident, though so far as I am aware this has not hitherto been pointed out, that, as already suggested, the compression and consequent folding of the strata (Fig. 43) would not be in the direction oi A B only, but also at right angles to it, in the direction of A O, though the amount of fold- ing might be much greater in one direction than in the other. Thus in the case of Switzerland, as the main folds run S.W. and N.E., the subsidiary ones would be N.W. and S.E. If these considerations are correct it follows that, though the main valleys of Switzerland have been im- 1 Beauties of Nature. VALLEYS 115 mensely deepened and widened by rivers, their original cause was determined by tectonic causes. Again they indicate why the long valleys are not more continuous. If we look for instance at a map of the Jura, we see that, though the ridges follow the same general curve from one end to the other, they are not continuous, but form a succession of similar but de- tached ridges. Moreover even when a valley is con- — Ji '^ B 2iii ^r _ — /)' Fig. 43. — Diagram in illustration of Mountain Structure. tinuous for many miles it is interrupted here and there by the cross folds. These considerations tlien seem to account for the two main directions of the Swiss valleys. I must add, however, that in Prof. Heim's opinion the cross folds occur in other parts of the Earth's sur- face ; and such bosses as the Furca and the Ober Alp are merely the battle grounds of different river systems, the lower levels being due to more rapid denudation. 116 SCENERY OF SWITZERLAND chap. ClKQTJBS In some cases valleys end in a steep amphitheatre known as a " Cirque." Cirques are characteristic of calcareous districts. They occur especially where a permeable bed rests on an impervious substratum. Under such circumstances a spring, in many cases intermittent, issues at the junc- tion and gradually eats back into the upper stratum, forming at first a semicircular enclave, which becomes gradually elliptic, and as time passes on more and more elongated, but always with a steep terminal slope. In the Jura, cirques are numerous, and in many cases a marly bed supplies the impermeable stratum. The Creux du Vent and the Cirque de St. Sulpice are two of the finest examples. Teeeaces As regards the sides of valleys, other things being equal, the harder the rocks the steeper will the slope of the sides be. Very hard rocks indeed are often almost, or for some distances quite, perpendicular. The slope may be uniform in cases where the strata are similar and of great thickness, as for instance in the valley of the Reuss, above Amsteg, where the Bristen- stock forms a grand pyramid of Crystalline rock, or where the slope coincides with the dip of the strata as in the valley of Lauterbrunnen where the right side of the valley presents immense sheets of Jurassic rock. In most cases however some of the strata along the side of the valley are harder than others, and the con- sequence is that we have a succession of terraces ; gentler slopes indicating the softer, and steeper ones the harder beds. VALLEYS 117 Figs. 44 and 45 show some terraces in the valley of the Bienne (Jura) due to the presence of hard calcare- ous layers. These "weather" terraces must not be confused with the "river terraces" which will be described in the next chapter. River terraces have no relation to the rock and follow the slope of the river, while weather terraces fol- low the lines of the strata. v>"--A ^^W Fig. 44. — Weather Terraces in the Valley of the Bienne (Jura). This consideration throws light on the cases in which a river valley expands and contracts, perhaps several times in succession. We often, as we ascend a river, after passing along a comparatively flat plain, find ourselves in a narrow defile, down which the water rushes in an impetuous torrent, but at the summit of which, to our surprise, we find another broad fiat expanse. This is especially the case with rivers running in a transverse valley. 118 SCENERY OF SWITZERLAND that is to say of a valley lying at right angles to the "strike" or direction of the strata (such, for instance, as the Reuss) ; the water acts more effectively than in cross rocks which in many cases differ in hardness, and which therefore of course cut down the softer strata more rapidly than the harder ones ; each ridge of Fig. 45. — Section showing Weather Terraces. harder rock will therefore form a dam and give rise to a rapid or cataract. In cases such as these each sec- tion of the river has for a time a "regimen" of its own. Suppose for instance a river a b (Fig. 46) running across the strike of several layers differing in hardness, A, 0, E being soft, while B, D are tough or hard. In such a case the valley will widen out at A, 0, U. Speak- A B C D E Fig. 46. — Diagram showing the Course of a River through Hard and Soft Strata. ing generally we may say that the depth of the valley is mainly due to the river erosion, the width to weather- ing. Thus the Urseren Thai on the St. Gotthard, the broad stretches of valley at Liddes, and at Chable on the Dranse (Valais) are due to the more readily dis- integrated Carboniferous or Jurassic strata. On the TI VALLEYS 119 otlier hand, the depth of the valley will tend to arrive at the regular " regimen " (Fig. 47), and must in any case follow its normal course ; but the width will de- pend on the destructibility of the strata. Even how- ever the hardest rocks will give way in time, so that the inclination of the sides will depend on the hardness of the rocks and the age of the valle3^ Other things being equal, the older the valley the gentler will be the slope of the sides. Flat valley plains may be formed either by rivers or in a lake, and the surface view is the same in either case. The inner structure, however, as shown in a sec- tion, is very different. A river plain shows irregular, lenticular masses of gravel and sand. A stream run- ning into a lake deposits fine mud in gently inclined layers, but as soon as it comes to the water's edge the coarser gravel rolls downwards forming a steeper slope. The great Swiss valleys are of immense antiquity ; the main ones indeed were coeval with the mountains, and date back to the formation of the Alps themselves. Many indeed were even deeper in glacial times, having been to a great extent filled up by glacial deposits. Penck states that longitudinal are generally older than cross valleys. It seems to me on the contrary that they would as a rule have begun simultaneously. No doubt, however, there were many exceptions. The Dranse was probably an older river than the Upper Rhone. The Rhine below Basle runs in a compara- tively recent depression. The greater number of the upper Swiss valleys must, however, date back to Mio- cene and some even to Eocene times, when rapid rivers were bringing down immense quantities of gravel from the slopes of the slowly rising Alps. CHAPTER VII ACTION OF EIVEES Although the elevation of the Swiss Alps is the result of geological causes, the present configuration of the surface is mainly due to erosion and denudation. It is indeed impossible to understand the physical geog- raphy of any country without some knowledge of the action of water, and especially of rivers. The velocity of a stream depends partly on the inclination of its bed, and partly on the volume of water ; if then we study an ancient river which has passed the stormy period of childhood and forced its way through the obstacles of middle life, so that its Fig. 47. — Final Slope of a Eiver. waters run with approximately equal rapidity, we shall find that the slope diminishes from its source to the sea or lake into which it falls, with some such curve as in Fig. 47. Such a river is said to have attained its " regimen," and this is the goal at which all rivers are striving to arrive. The course of a river may be divided into three stages which may be and often are repeated several times, viz. : — 120 CHAP. VII ACTIOK OP EIVEES 121 1. Deepening and widening (the torrent) ; 2. Widening and levelling (the river proper); 3. Filling up (the delta) ; and every part of a river in the second stage has passed through the first, every one in the third through the other two. In the Valais the Upper glacier is a valley in the second stage, the ice-fall in the first; the plain from the foot of the fall to the Hotel in the second, from the Hotel to near Oberwald in the first ; from Oberwald nearly to Niederwald in the second, from Niederwald to rather beyond Viesch in the first ; then on to Brieg in the second, and from St. Maurice to Villeneuve in the third. First Stage In the first phase the river has a surplus of force. It may be called a torrent. It cuts deeper and deeper into its valley, and carries away the mud and stones to a lower level. The sides are steep, as steep indeed as the nature of the material will permit, and the valley is in the shape of a V with little, if any, flat bottom. The water moreover continually eats back into the higher ground. The character of the valley depends greatly on that of the strata, being narrower where they are hard and tough, broader on the contrary where they are soft, so that they crumble more easily into the stream under the action of the weather (Fig. 46). In several cases indeed the Swiss rivers run through gorges of great depth, and yet very narrow, even in some places with overhanging walls. The Via Mala, which leads from the green meadows of Schams (Sex- amniensis from its six brooks) to Thusis, is about five miles in length with a depth of nearly 500 metres, and 122 SCENERY OP SWITZBELAND chap. very narrow, in one place not more than 9 to 15 metres in breadth. The gorges of the Aar, of the Gorner, of the Tamina at Pfaffers, of the Trient, have a similar character. These were formerly supposed to be fissures due to upheaval. They none of them however present a trace of fracture; marks of water action can in places be seen from the base to the summit, and there can be no doubt that they have been cut through by the rivers. In certain cases indeed we have conclusive evidence. Some of these gorges are left at times quite dry, and it is easy then to see that the rock is continuous from side to side. The tunnels on the St. Gotthard line pass no less than six times under the Reuss and there is no trace of a fault. It may I think be said that the theory which attrib- uted these gorges to a split in the rock, is now defi- nitely abandoned. Of course, however, there are some cases in which the courses of streams have been determined by lines of fault and fracture. Second Stage The second stage commences Avhere the inclination becomes so slight that the river can scarcely carry av/ay the loose material brought from above, or showered down from the sides, but spreads it over the valley, in which it wanders from side to side, and which it tends continually to widen. Hence unless they are confined by artificial embankments, such rivers are continually changing their course, keeping however within the limits of the same valley. The width of the valley moreover depends on its age, as well as on the size of the river and the character of the rock. VII ACTION OF EIVEKS 123 If we imagine a river running down a regularly- inclined plane in a more or less straight line, any in- equality or obstruction, or the entrance of a side stream, would drive the water to one side, and when once diverted it would continue in the new direction, until the force of gravity drawing the water in a straight line downwards equalled that of the force tending to divert its course. Hence the radius of the curves will follow a regular curve law depending on the volume of water and the angle of inclination of the bed. If the fall is ten feet per mile and the soil homogeneous, the curves would be so much extended that the course would appear almost straight. Much labour has been lost in trying to prevent rivers from following their R ^ Fig. 48. — Diagrammatic Section of a Valley (exaggerated). UR, rocky basis of valley \iAA, sedimentary strata ; B, ordinary level of river ; C, flood level. natural laws of oscillation. But rivers are very true to their own laws, and a change at any part is continued both upwards and downwards, so that a new oscillation in any place cuts its way through the whole plain of the river both above and below. If the river has no longer a sufficient fall to enable it to carry off the materials it brings down, it gradually raises its bed (Fig. 48) ; hence in the lower part of their course many of the most celebrated rivers — the Po, the Nile, the Mississippi, the Thames, etc. — run upon em- bankments, partly of their own creation. The Reno, the most dangerous of all the Apennine 124 SCENEEY OF SWITZERLAND chap. rivers, is in some places more than 9 metres above the adjoining country. Rivers under such conditions, when not interfered with by Man, sooner or later break through their banks, and leaving their former bed, take a new course along the lowest part of their valley, which again they gradually raise above the rest. Along the valley of the Rhone from Visp down to the Lake of Geneva there is often a marsh on one side of the valley, sometimes on both, the existence of which is to be thus explained. This is the second stage. Thied Stage Finally when the stream falls into a lake or sea, or joins a main valley, it cannot carry farther the stones and mud which it has brought down, and spreads them out in the form of a fan, forming a more or less flat cone or delta ; a cone if in air, a delta if under water ; and the greater the volume of water, the gentler will the slope be, so that in great rivers it becomes almost imperceptible. At this part of its course the stream, instead of meandering, will tend to divide into several branches. Cones and deltas are often spoken of as if they were identical. The surface and slope are indeed similar, but the structure of a delta formed under water (see p. 119) is by no means the same as that of a cone formed in the air. Deltas have generally a very slight inclination, so far as the surface is concerned, while the layers below stand at a greater inclination. Most of the Swiss lakes are being gradually filled up by the deposits of rivers. The Lake of Geneva once extended far up the Rhone valley to St. Maurice if not to Brieg. It presents also a very ACTION OF EIVEKS 125 typical delta at the mouth of the Dranse near Thoiion. Between Vevey and Villeneuve are several such promon- tories, each marking the place where a stream falls into the lake. Where lateral torrents fall into a main valley, the rapidity of the current being checked, their power of 126 SCENEKY OF SWITZERLAND transport is diminished and similar " river cones " are formed. A side stream with its terminal cone, when seen from the opposite side of the valley, presents the appearance shown in Fig. 49, or, if we are looking down the valley, as in Fig. 50, the river being often driven to one side of the main valley, as, for instance, is the case ACTION OF RIVERS 127 in the Valais near Sion, where the Rhone is (Fig. 51) driven out of its course by, and forms a curve round, the cone formed by the liiver Borgne. The river cones are, in many cases, marked out by the character of the vegetation. " The Pines enjoy the stony ground particularly, and hold large meetings upon it, but the Alders are shy of it, and, when it has come to an end, form a triumphal procession all round its edge, following the convex line.''^ The magnitude of these " river cones," then, depends Fig. 51. — Map showing junction of Rhone and Borgne. on the amount and character of the materials brought into the main valley, and on the power of the river to carry them off. The felling of forests, for instance, in a lateral valley will considerably increase the erosive power of the stream, and the amount of material brought down. Rocks which yield readily to the action of weather and water will naturally supply most material, and give rise to the largest cones, especially if they form 1 Euskin, Modern Painters, vol. iv. 128 SCBNEEY OP SWITZERLAND CHAP. hard pebbles. On the other hand, the Flysch, which as a rule exercises little resistance, does not produce such important cones as might be expected, because it disintegrates into fine particles which are easily washed away. The Cargneule, on the contrary, produces large cones, because it breaks up readily, but into hard pieces. Such cones sometimes raise the bed of the valley and dam back the water, and thus form a marshy and un- healthy tract. Thus in the Upper Valais below Ober- wald is a succession of such cones, one succeeding another, and with more or less marshy ground between them. At Miinster there is a fine cone, and further down are many others at intervals. The two largest are those of the Illgraben at Leuk, and the Chamoson at the mouth of the Losentze, both of which raise the level of the valley above several feet. That of the Borgne (Fig. 51), near Sion, drives the river to the foot of the opposite mountain. When at length a river has so adjusted its slope that it neither deepens its bed in the upper portion of its course, nor deposits materials, it is said to have acquired its " regimen " (Fig. 47), and in such a case the veloc- ity will be uniform. The enlargement of the bed of a river is not, however, in proportion to the increase of its waters as it approaches the sea. Other things being equal, a river which increases in volume, increases in velocity ; the " regimen " therefore would be destroyed, and the river would again commence to eat out its bed. Hence, if rivers enlarge, as for instance owing to any increase in territory, the slope diminishes. The following figure (Fig. 52) gives a sketch map, and Fig. 53 represents the profiles, of the principal rivers in the valley of the Garonne, and it will be seen that the larger the river the gentler is the slope. At present many of the smaller Swiss streams are ACTION OF EIVEKS 129 eating into their cones and endeavouring to flatten them, owing perhaps to the gradual enlargement of the gathering grounds. These cones are favourite sites for villages, which Fig. 52. — River system of the Garonne. are thus raised and placed out of danger of ordinary floods. The loose materials of the upper part of the cone, moreover, absorb water freely in the upper part, which is filtered, and emerges in clear springs lower down. Thus arise many of the fountains in such villages. Now let us suppose that the force of a river is again Fig. 63. — Slopes of the Garonne and its Principal Affluents. increased, either by a fresh elevation, or locally by the removal of a barrier, or by an increase in volume owing to an addition of territory, or greater rainfall; it will then again cut into its own bed, deepening the valley. 130 SCENEBY OP SWITZBKLAND and giving rise to a rapid, which will creep gradually up the valley, receding of course more rapidly where the strata are soft, and lingering longer at any hard ridge. The old plain of the valley will form a more or less continuous terrace above the new course. Such old river terraces may be seen in most valleys, often indeed several, one above another. It has been sometimes supposed that these terraces indicated greater volume of water in ancient times, S o -3 a H S S t] .21 Fig, 54. — Section across the valley of the Ticlno. On the left from the Ticino to Campolungo ; on the right by Altanca to P.nera. sufficient indeed to fill up the whole valley to that depth. It must be remembered, however, that the terrace was formed before the lower part of the valley was excavated. Fig. 54 is a section across the valley of the Ticino, a short distance below Airolo. It shows two high terraces on which the lakes Tom and Ritom are re- spectively situated, and which correspond to those of Campolungo and Tremorgia on the other (W.) side of VII ACTION OF BIVEES 131 the valley. Below them is another terrace at a height of 1350 metres, on which Altanca stands. This terrace can he traced for some distance, and bears a series of villages — Altanca, Ronco, Beggio, Catto, Osco, etc. In the valley of the Ticino there is a second series of still more important towns, at or at least little above, the present river bed ; but in other cases, as, for in- stance, along the Plessur, which falls into the Rhine at Chur, the present river bed is quite narrow, and the Cola is Sotto sx'>>v-5 -^/"^ '^■^ «'?\V/--^^7=sr--~- ----// ..^>s Fig. 55. — River Terraces in Val Camadra. villages are on an old river terrace high above the pres- ent water level. Fig, 55 represents a group of terraces in the Val Camadra. In each river system the terraces occupy correspond- ing levels, but in different systems they have no relation to one another. They afford, as we shall see in the next chapter, valuable evidence as regards the former history of rivers. Hitherto I have assumed that the river deepens its bed vertically. This is not, however, always the case. If the strata are inclined the action of the water will tend to foUow the softer stratum, as for instance in the 132 SCENEKY OP SWITZERLAND Fig. 56. — Diagram of River Valley. following diagram, where A represents a harder calca- reous rock overlying a softer bed B. The enormous amount of erosion and denudation which has taken place may be estimated from the fact that terraces can still be traced in some cases at a height of over 3000 metres. As we approach their source, valleys become steeper and steeper. In some cases, and espe- cially in calcareous dis- tricts, the valleys end in a precipitous, more or less semi-circular " Cirque." Springs rising at the foot of such escarpments are known as Vauclusian, from the celebrated and typical instance at Vaucluse. Another interesting point brought out by the study of Swiss rivers, is that just as in Geology, though there have no doubt been tremendous cataclysms, still the main changes have been due to the continuous action of existing causes ; so also in the case of rivers, how- ever important the effects produced due to floods, still the configuration of river valleys is greatly due to the steady and regular flow of the water. Floods may be divided into two classes, (1) those due to the bursting of some upper reservoir, such, for instance, as the great flood of the Dranse de Bagnes in 1818, due to the outburst of the lake, which had been dammed back by the glacier of Gietroz, or the more recent flood of St. Gervais ; and (2) those due to heavy rains. No one can travel much in Switzerland without seeing the great precautions taken to confine the rivers within certain limits. In fact, what we call the river Til ACTION OF EIVEES 133 bed is rather the low-water channel, and the whole bottom of the yalley would, but for these precautions, be covered during any considerable flood. Egypt itself is the river bed of the Nile during the winter flood. Giants' Caldbons These are more or less circular cavities, often some- what raised in the centre. They sometimes attain a considerable size — as much as 8 metres in diameter and 5 in depth. There is a very fine group at Lucerne, where they are known as the "Jardin du Glacier." They have been excavated in the rock by blocks of harder stone being whirled round by the action of water. Some of them no doubt, and probably those at Lucerne, were formed under glaciers, at the foot per- haps of a " moulin," but I believe that as a rule the)^ were formed in streams.^ Several have recently been discovered at the Maloja ; there are some specimens also near Servoz in the valley of the Arve. Renevier points out that such caldrons can be seen actually in process of formation in some of the existing rivers, as, for instance, near the junction of the Rhone and the Valorsine below Geneva. These, however, will be de- stroyed as erosion continues. Surprise is sometimes expressed that Giants' Caldrons occur where no stream now flows. But it is just to this fact that they owe their existence. If the river had not changed its course they would long since have been destroyed. Before closing this chapter I must say a few words about subterranean streams. These occur mainly in porous rocks, such as those of the Jura. The most considerable of these partly subterranean rivers is the iPavre, Beck. Geol. v, i. 134 SCENBEY OIT SWITZERLAND chap. Orbe, which rises originally in a little French lake, Les Rousses, traverses two others on Swiss territory, the Lake de Joux, and that of Brenet, and then disappears suddenly in the ground at the foot of a high cliff, reap- pearing again at a distance of 3 km. near Vallorbes. Summing then up this chapter we may say that as soon as any tract of land rose out of the sea, the rain which fell on the surface would trickle downwards in a thousand rills, forming pools here and there, and gradu- ally collecting into larger and larger streams. When- ever the slope was sufficient, the water would begin cutting into the soil and carrying it off to the sea. This action would, of course, differ in rapidity accord- ing to the slope and hardness of the ground. The character of the valley would depend greatly on the nature of the strata, being narrow where they were hard and tough ; broader, on the contrary, where they were soft, so that they crumbled readily into the stream, or where they were easily split by the weather. Gradu- ally the stream would eat into its bed until it reached a certain slope, the steepness of which would depend on the volume of water. The erosive action would then cease, but the weathering of the sides and consequent widening would continue, and the river would wander from one part of the valley to another, spreading the materials and forming a river plain. At length, as the rapidity still further diminished, it would no longer have sufficient power even to carry off the materials brought down. It would form therefore a cone or delta, and instead of wandering would tend to divide into different branches. When we look at some great valley of denudation and the comparatively small river which flows through it, we may deem it almost impossible that so great an effect can be due to so small a cause. We can, how- VII ACTION OP RIVERS 135 6ver, find every gradation from the little gully cut out by the last summer shower up to the great Canon of Colorado. We must consider not only the flow of the water, but the lapse of time, and remember that our river valleys are the work of ages. Moreover, even without postulating any greater rainfall in former times, we must bear in mind that we are now looking at rivers which have attained or are approaching their equilib- rium ; they are comparatively steady, and even aged, and we cannot measure their present effect by that which they produced when they possessed the energy and impetuosity of youth. BVom this point of view the upper part of a river val- ley is peculiarly interesting. It is a beautiful and in- structive miniature. The water forms a sort of small meshed net of tiny runnels. Here we can as it were surprise the river at its very commencement ; we can find streamlets and valleys in every stage, — a quartz pebble may divert a tiny stream, as a mountain does a great river ; we find springs and torrents, river terraces and waterfalls, lakes and deltas, in the space of a few square metres, and changes which on a larger scale require thousands of years pass under our eyes. And as we watch some tiny rivulet, swelling gradually into a little brook, joined by others from time to time, growing to a larger and larger torrent, to a stream, and finally to a great river, it is impossible to resist the conclusion gradually forced upon us, that, incredible as it must at first sight appear, even the greatest river valleys, though their origin may be due to the original form of the surface, owe their present configuration mainly to the action of rain and rivers. Note. — Throughout western Europe a large propor- tion of the river names fall into three groups. 136 SCENERY OP SWITZERLAND chap, vii From the Old German Aha, Celtic Uisge, Gaelic Oich, Latin Aqua, Water, softened into the French Eau, we have the Aa, Awe, Au, Avon, Aue, Ouse, Oise, Grand Eau, Aubonne, Oieh, Ock, Aach, Esk, Uisk, etc. From the Celtic Dwr (Greek vSeop'), we have Oder, Adour, Thur, Dora, Douro, Doire, Durance, Dranse,. Doveria, etc. From the Celtic Rhin, or Rhedu, to run, Greek pm, we have the Rhine, Rhone, Reuss, Reno, Rye, Ray, Raz, etc. The names Aa and Drance or Dranse are so common in Switzerland that it is necessary to specify them by some further description, such as the Engelberger Aa, the Aa of Alpnach, the Milch Aa, Hallwyler Aa, Waggithaler Aa, etc. The Drance which falls into the Lake of Geneva near Thonon is perhaps the Drance par excellence, but in the same river system we have also the Drance de Bagne, the Drance d'Entremont, and the Drance de Ferret. In the case of the Rhine also there is the Vorder Rhein, Mittel Rhein, Hinter Rhein, Oberhalbstein Rhein, Averser Rhein, Safien-Rhein, etc. CHAPTER VIII DIRECTIONS OF EIVEES The general direction of the river courses in any country is determined in the first instance by the con- figuration of the surface at the time of its becoming dry land. The least inequality in the surface would determine the first direction of the streams, and thus give rise to channels, which would be gradually deep- ened and enlarged. They are, however, in many eases materially modified by subsequent changes of relative level, and by the results of erosion, which acts of course much more rapidly on some strata than on others. It is as difiicult, however, for a river as it is for a man to get out of a groove. If we imagine a district raised in the form of a regu- lar dome, the rivers would radiate from the summit in all directions. The lake district in the north of Eng- land; the Plateau of Lanneme-zan in the south of France, and the Ellsworth Arch in the Henry Moun- tains,^ offer us approximations to such a condition. It seldom happens, however, that the case is so simple; and the directions of rivers offer many interesting problems, which are by no means easy to solve. As already mentioned (ante, p. 110), the Swiss rivers follow two main directions, at right angles to one another, namely, S.W. by N.E. and N.W. by S.E. The first follows the strike of the strata. The explana- 1 See Gilbert, Geology of the Henry Mountains. 137 138 SCENBEY OF SWITZERLAND CHAP. tion of the second is not so simple. The probable cause, however, which has determined the two main directions of the Swiss rivers has been already sug- gested (anie, p. 114). The principal Swiss rivers must be of great antiquity. Some of the streams in the eastern and central parts of the Alps probably commenced even in Eocene times. The Nagelflue was brought down from the mountains by rivers which probably occupied the upper parts of the valleys of the Aar, Reuss, etc. Nevertheless there have been great changes in the courses of the Swiss rivers. These are ascribable to four main causes : First, it must be remembered that streams are continually eating back into the hills. In many cases they cut completely through them, and if the valley into which they thus force their way is at a higher level, they carry off the upper waters ; Secondly, later earth movements in many cases diverted the rivers ; Thirdly, they have in many cases been diverted by masses of glacial deposits ; and Fourthly, the sum- mit ridge of the Alps is slowly retreating northwards, which affects the river system of all the upper districts. In the great Swiss plain the country slopes on the whole northwards from the Alps, so that the lowest part is that along the foot of the Jura. Hence (Fig. 42) the main drainage runs along the line from Yver- dun to Neuchatel, down the Zihl to Soleure, and then along the Aar to Waldshut. The Upper Aar, the Emmen, the Wigger, the Suhr, the Wynen, the lower Reuss, the Sihl, and the Limmat, besides several smaller streams, running approximately parallel to one another — N.N.W., and at a right angle with the main axis of elevation, all join the Aar from the south, while on the north it does not receive a single tributary of any importance. vm DIRECTIONS OF KIVBES 189 On the south side of the Alps again, and for a corresponding reason, all the great affluents of the Po — ^the Dora Baltea, the Sesia, the Ticino, the Olonna, the Adda, the Adige, etc. — -come from the north, and all run S.S.E. from the axis of elevation to the Po. Indeed, the general slope of Switzerland being from the ridge of the Alps towards the north, most of the large affluents of rivers running in longitudinal val- leys fall in on the south, as, for instance, those of the Is^re from Albertville to Grenoble, of the Rhone from its source to Martigny, of the Vorder Rhine from its source to Chur, of the Inn from Landeck to Kufstein, of the Enns from its source to near Admont, of the Danube from its source to Vienna, and, as just men- tioned, of the valley from Yverdun to Waldshut. Hence also, whenever the Swiss rivers running east and west break into a transverse valley, as the larger ones all do, and some more than once, they invariably, whether originally running east or west, turn towards the north. But why has the country this slope? Why is it lowest along the wall of the Jura ? As has been already pointed out, this part of Switzerland was formerly a great valley, which was partially filled by river deposits. It is indeed a great " cone " due to many rivers which flowed down from the rising Alps. This being so, the general slope is naturally from, and the lowest part is that farthest away from, the mountains. It must be remembered that the conformation of the strata situated below by no means always corresponds with that of the surface. Again it will sometimes happen that rivers follow a course which is very difficult to explain, because, in fact, it has no refer- ence to the present configuration of the surface, but 140 SCENERY OF SWITZERLAND chap. has been determined by the existence of strata which have now disappeared. It often happens, for instance, that the rivers now run apparently on an anticlinal, and have a synclinal on one side (Fig. 57), as, for instance, the Rhine at Dissentis (see Fig. 135). The folds, however, being inclined, it will be seen from the dotted lines that when the river began its labour it perhaps did run in the synclinal, but having Fig. 57. — Diagram to illustrate a River now running in an Anticlinal. out its way directly downwards is now some way from it, and will diverge further and further as erosion proceeds. It is a remarkable fact that great folds by no means always determine the watershed, but, on the contrary, rivers often cut through ranges of mountains. Thus the Elbe cuts right across the Erz-Gebirge, the Rhine through the mountains between Bingen and Coblenz, the Potomac, the Susquehanna, and the Delaware through the AUeghanies. Even the chain of the Himalayas, though the loftiest in the world, is not a watershed, but is cut through by rivers in more DIRECTIONS OF EIVERS 141 than one place. The case of the Dranse will be alluded to further on. In these instances the rivers probably preceded the mountains. Indeed, as soon as the land rose above the waters, rivers would begin their work, and having done so, if a subsequent fold commenced, unless the rate of elevation exceeded the power of erosion of the river, the two would proceed simulta- neously, so that in many cases the river would not alter its course, but would cut deeper and deeper as the mountain range gradually rose. In other cases where we generally speak of a river Fig. 58. — Sketch Map of the Ehone and its Tributaries. suddenly changing its direction, it would be more cor- rect to say that it falls into the valley of another stream. Thus the Aar, below Berne, instead of con- tinuing in the same direction, by what seems to have been its ancient course, along the broad valley now only occupied by the little Urtenenbach, suddenly turns at a right angle, falling into the valley of the Sarine, near Oltigen. Take again the Rhone (Fig. 58). It is said to turn 142 SCENERY OP SWITZERLAND chap. at a right angle at Martigny, but in reality it falls into and adopts the transverse valley, which properly belongs to the Dranse; for the Dranse is probably an older river and ran in the present course even before the origin of the Valais. This would seem to indicate that the Ober- land range is not so old as the Pennine, and that its ele- vation was so gradual that the Dranse was able to wear away a passage as the ridge gradually rose. After leav- ing the Lake of Geneva the Rhone follows a course curv- ing gradually to the south, until it falls into and adopts a valley which properly belongs to the Valserine, and afterwards another belonging to the little river Guiers ; it subsequently joins the Ain, and finally falls into the Saone. If these valleys were attributed to their older occupiers, we should therefore confine the name of the Rhone to the portion of its course from its source to Martigny. From Martigny it invades successively the valleys of the Dranse, Valserine, Guiers, Ain, and Saone. In fact, the Saone receives the Ain, the Ain the Guiers, the Guiers the Valserine, the Valserine the Dranse, and the Dranse the Rhone. This is not a mere question of names, but also one of antiquity. The Saone, for in- stance, flowed past Lyons to the Mediterranean for ages before it was joined by the Rhone. In our nomenclat- ure, however, the Rhone has swallowed up the others. This is the more curious from the fact that of the three great rivers which unite to form the Lower Rhone, namely, the Saone, the Doubs, and the Rhone itself, the Saone brings for a large part of the year the great- est volume of water, and the Doubs has the longest course. We will now consider some of the cases in which Swiss rivers have altered their courses. In some of these the change of direction is doubtless due to the VIII DIRECTIONS OF RIVERS 143 fact that some stream at the lower level, or with a greater fall, has eaten its way back, and so tapped the higher valley. Rivers, indeed, have their adventures and vicissi- tudes, their wars and invasions. Take, for instance, the Upper Rhine (Fig. 59),. of which we have a very ^^ /A^aAuT, z„fmau„.uuit \ /^ V >aWai"j(HM / yv^«^ ■1 ^Clnir Verein^ iTieichena ei^ ThusisS Heida <^ .^ Fig. 59. — River System round Chur, as it is. interesting account by Heim. It is formed of three main branches, the Vorder Rhine, the Hinter Rhine, and the Albula. The two latter, after meeting near Thusis, unite with the Vorder Rhine at Reichenau, and run by Chur, Mayenfeld, and Sargans into the Lake of 144 SCBNEEY OF SWITZERLAND Constance at Rheineck. At some former period, how- ever, the drainage of this district was very different. The Vorder and Hinter Rhine united then, as they do now, at Reichenau, but at a much higher level, and ran to Mayenfeld (Fig. 60), not by Chur, but by the Kunkels Pass to Sargans, and so onwards, not to the Fig. 60. — River System round Chur, as it used to be. Lake of Constance, but to that of Ziirich. The Land- wasser at that time rose in the Schlappina Joch, and after receiving as tributaries the Vereina and the Sar- dasca, joined the Albula, as it does now at Tiefen- kasten; but instead. of going round to meet the Hinter DIRECTIONS OF RIVERS 145 Rhine near Thusis, the two together travelled parallel with, but at some distance from, the Hinter Rhine, by Heide to Chur, and so to Mayenfeld. As we look up from Tie- fenkasten towards Lenz and the Parpan Pass it seems almost incredible that the Oberhalbstein Rhine can ever have taken that course. I give therefore (Fig. 61) the following profile showing the old river ter- race, but with the height exaggerated in compari- son with the distance. This, however, does not affect the relative eleva- tions. The dotted lines follow the natural slope of a river, and the strength- ened parts show where portions of terrace still remain. It is obvious that before the ancient Schyn had cut its way up to Tiefenkasten the Oberhalbstein Rhine and the Landwasser flowed over the Parpan Pass, and not only flowed over it, but have cut it down 6SEE MBpmwj^ 04I> B37ii?Bn3pBO S30f uapiUMiiiHo i"! i- «MS aasciiaqo— f-H I eeu araiHsany-japj^ T-6SF eas JezWjt" EE6E XOMz-ivx ''Tl I ' i i ! ' r £388 uajBuJinajBix'" tCZ9 Iim»S- 809E waanmiaMitba 16E9-E6Z9 OUBJOS qui mioiBOs' SSii spnopuj flejo" 188! Oiisa 998Z enBjiu_A.. 0E08-99eZ SVAIVSUAVJf) ip ■'T 146 SCEMEEY OF SWITZEELAKD chap. some 610 metres, that is to say, when the river flowed over it with its natural regimen in relation to the valley it was at a height of 2200 metres, and has left a frag- ment of terrace at that height at Vor der Angstberg, the Parpan itself being only 1500 metres. In fact, the Parpan and Kunkels passes are deserted river valleys, showing on each side river terraces, and were obviously once the beds of great rivers, very dif- ferent from the comparatively small streams which now run in their lower parts. In the meanwhile, however, the Landquart stealthily crept up the valley, attacked the ridge which then united the Casanna and the Madrishorn, and gradually forcing the passage between Dorfli and Klosters, invaded the valleys of the Schlappina, Vereina, and Sardasca, absorbed them as tributaries, detached them from their allegiance to the Landwasser, and annexed the whole of the upper province which had formerly belonged to that river. The Schyn also gradually worked its way upwards from Thusis till it succeeded in sapping the Albula and carried it down the valley to join the Vorder Rhine near Thusis. In what is now the main valley of the Rhine above Chur, another stream ate its way back, and eventually tapped the main river at Reichenau, thus diverting it from the Kunkels and carrying it round by Chur. It is possible that in the distant future the Landwasser may be still further robbed of its territory. The waters of the Davos Lake, the Fliiela, the Dischma, and the Kuhalpthal now take a very circuitous route to Chur, and it is not impossible that they may be captured and carried off by the Plessur. At Sargans a somewhat similar process was repeated, with the addition that the material brought down by vm DIRECTIONS OF EIVERS 147 the Weisstanneh, or perhaps a Rockfall, deflected the Rhine, just as we have seen (p. 126) that the Rhone was pushed on one side by the Borgne. The Rhone, however, had no clioice : it was obliged to force, and has forced, its way over the cone deposited by the Borgne. The Rhine, on the contrary, had the option of running down by Vaduz to Rheinbach, and has adopted this course. The association of tlie three great European rivers — the Rhine, the Rhone, and the Danube — with the past history of our race, invests them with a singular fascination, and their own story is one of much inter- est. They all three derive part of their upper waters from the group of mountains between the Galen- stock and the Bernardine, within a space of a few miles ; on the east the waters now run into the Black Sea, on the north to the German Ocean, and on the west to the Mediterranean. But it has not always been so. Their head-waters have been at one time interwoven together. The present drainage of western Switzerland is very remarkable. If you stand on a height overlooking the valley of the Arye near Geneva, you see a semicircle of mountains — the Jura, the Vuache, the Voirons, etc., which enclose the west end of the Lake of Geneva; the Arve runs towards the lake, which itself opens out tow- ards Lausanne, where a tract of low land alone sepa- rates it from the Lake of Neuch&tel and the valley of the Aar. This seems the natural outlet for the waters of the Rhone and the Arve. As a matter of fact, how- ever, they escape from the Lake of Geneva at the western end, through the remarkable defile of Fort de I'Ecluse and Maupertuis, which has a depth of nearly 300 metres, and is at one place not more than 14 feet across. There are reasons, moreover, as we shall see 148 SCBNEBY OP SWITZERLAND chap. presently, for considering the defile to be of compara- tively recent origin. Moreover, at various points round the Lake of Geneva, remains of lake terraces show that the waters once stood at a level much higher than at present. One of these is rather more than 76 metres above the lake. The low tract between Lausanne and Yverdun has a height of 76 metres (250 feet) only, and corresponds with the above-mentioned lake terrace. The River Venoge, which rises between RoUe and the Monte Tendre, runs at first towards the Lake of Neuchatel, but near La Sarraz it divides ; the valley continues in the same direction, and some of the water joins the Nozon, which runs to the Lake of Neuchatel at Yver- dun ; but the main river turns sharply to the south, and falls into the Lake of Geneva to the east of Morges. It is probable, therefore, that when the Lake of Geneva stood at the level of the '76-metres terrace the waters ran out, not as now at Geneva and by Lyons to the Mediterranean, but near Lausanne by Cissonay and Entreroches to Yverdun, and through the Lake of Neu- chatel into the Aar and the Rhine. But this is not the whole of the curious history. At present the Aar makes a sharp turn to the west at Waldshut, where it falls into the Rhine, but there is reason to believe that at a former period, the river con- tinued its course eastward to the Lake of Constance, by the valley of the Klettgau, as is indicated by the presence of gravel beds containing pebbles which have been brought, not by the Rhine from the Grisons, but by the Aar from the Bernese Oberland, showing that the river which occupied the valley was not the Rhine but the Aar. It would seem also that at one time the Lake of Constance stood at a considerably higher level, and that the outlet was, perhaps, from Friedrichshafen DIRECTIONS OF RIVERS 149 to Ulm, along what are now the valleys of the Schussen and the Ried, into the Danube.^ The river Aach, though a tributary of the Rhine, still derives its head-waters from the valley of the Danube. A part of the water of the Danube sinks into fissures in the Jurassic rocks at Immendingen, and makes its appearance again as copious springs at Aach, from whence it flows into the Lake of Con- stance near Rudolphzell. Thus the head-waters of the Rhone appear to have ■Feet 1230S- 9833- 8194- 6555- 4916- 3277- 1639- Fig. 02. — Section across the Val d'Entremont at Bourg St. Pierre. 1 = 100,000. originally run between Morges and Lausanne and to the Lakes of Neuchatel and Constance into the Danube, and so to the Black Sea. Then, after the present val- ley was opened between Waldshut and Basle, they flowed by Basle and the present Rhine, and after join- ing the Thames, over the plain which now forms the German Sea into the Arctic Ocean between Scotland 'Du Pasquier, BeUr. z. Geol. K. d. Schw., L. 150 SCENERY OP SWITZERLAND and Norway. Einally, after the opening of the passage at Fort de I'Bcluse, by Geneva, Lyons, and' the valley of the Saone, to the Mediterranean. Ill the upper parts of the district there have also been some changes. Fig. 62 shows the river terraces on the Dranse d'Entremont, near Bourg St. Pierre, where the Society for the protection of Alpine plants have established a very interesting Alpine garden, and (Fig. 63) those further down the valley near La Douay. The uppermost of these terraces is at a height of 2200 Fig. 63.- - Cross section of the Valley of the Dranse, between the Valley of Champey, Sembranchier, and Orsieres. metres. The col leading to the Vallee de Champey is at a height of about 1500 metres, and until the river had reached a lower level than this, the waters of the Dranse followed what the map shows was their natural course down the Vallee de Champey. Eventually, however, the Orsieres branch of the Dranse de Bagne cut its valley back and carried off the upper waters to join the Dranse de Bagne at Sembranchier. This was facilitated by the comparative softness of the Jurassic vm • DIBECTIONS OF RIVERS 151 strata ana Gray Schists, while the Vallee de Champey is in Protogine, Felsite, and Porphyry, which offered a much greater resistance to the action of the water, i The Trient also has changed its course. Originally it ran over the Col de la Forclaz down to Martigny. In this case the change is due, not to any difference in the hardness of the rock, but to the greater fall, and consequently greater erosive power of the Eau Noire. It would also seem that some of the Vaud and Frie- burg rivers must be older than the final elevation of the mountains at the north-east end of the Lake of Geneva. Gillieron points out that the Broye, the Mionnaz, the Flon, and I may add the Sarine, from Sarnen to below Chateau d'Oex, run towards the Lake of Geneva, until they are stopped by the mountains between Chatel St. Denis and the Rocher de Naye, and forced to return northwards. There is also one important change which applies to the whole crest of the Alps. Watersheds are at first determined by the form of the earliest terrestrial surface, and if the slopes in each side are equal they will be permanent ; on the other hand if, as in the Alps, one side is much steeper than the other, it will be worn back more rapidly. Hence the whole crest of the Alps is, of course, very slowly moving northwards. This is specially marked in the case of the Engadine (see ch. 24). These changes and struggles have by no means come to an end. In some cases we can already foresee future changes. For instance, the NoUa, which falls into the Hinter Rhine at Thusis, is rapidly eating back into the mountains near Glas, and in, geologically speaking, a comparatively short time it will probably invade the 1 Bodmer, p. 21. 152 SCENEEY OF SWITZERLAND chap, vm valley of the Versam, carry off its upper feeders, and appropriate the waters from the upper valley. So rap- idly is the change progressing that after even a few hours' rain the NoUa becomes quite black. In its upper part the Biindnerschiefer is saturated with water, and reduced almost to a black mud. It may be said to be continually in slow movement down to the valley, and the houses of Glas and Tschappina have to be continu- ally repaired. Some have moved as much as 60 metres downwards in thirty years. Age op Rivbks It follows from these considerations not only that the Swiss rivers are of very different ages, some being of comparatively recent origin, while others date back to very great antiquity, but that different parts of what is now considered a single river are of very different ages and have a very different history. The southern part of the Central Alps is supposed to have been first raised above the waters, and to have formed an Island in Eocene times, to which therefore some of the head-waters date back. It is, however, clear that the rivers crossing the Miocene deposits of central Switzerland cannot have commenced until after the Miocene strata had been raised and become dry land. In fact the upper parts of the Reuss and the Aar probably represent the rivers which brought down the great masses of Miocene gravel which now form the lowlands of Switzerland, and through which they subsequently cut the lower parts of their courses, which therefore must necessarily be of much less ancient origin ; even these valleys, however, were as a rule excavated to their full depth before the Glacial period, and must therefore be of immense antiquity. CHAPTER IX THE LAKES The Alps are surrounded by a beautiful circle of lakes. We have on the north, besides many smaller ones, those of Constance, Walen and Ziirich, Zug, Lucerne, Brienz and Thun, Geneva ; on the south the Lago Maggiore, Lugano, Como, Iseo, and Garda, which seem to radiate as it were from the great central mass of the St. Gotthard. I do not mention the Lakes of Neuchatel or Morat, because they belong to a different category. These great lakes are clearly not parts of a former inland sea. They stand at very different levels. The Lake of Brienz, for instance, is 190 metres above that of Geneva ; that of Orta is 225 metres above the Lake of Garda. But in considering the origin of these lakes we must have regard not merely to the surface level of the water, but also that of the bottom. When we give the level of a lake it is usual to quote that of the upper surface, but the bottom is perhaps even more important, and as we shall see from the following table, there is a great contrast between the two. Surface Level. Greatest Depth. Bottom Level. Constance 895 metres 252 metres 148 metres Walen 423 « 151 " 272 " Zurich 409 " 142 « 267 " Zug 417 " 198 « 219 " 153 154 SCENERY OP SWITZERLAND Surface Level. Geeatest Depth. Bottom Level. Lucerne 437 metres 214 metres 223 metres Sempach 507 it 87 " 420 Brienz 566 (( 261 it 305 Thun 560 a 217 it 345 Geneva 375 il 309 a 66 Neuchatel 432 a 153 a 279 Bienne 434 11 74 a 357 Orta 290 il 143 a 147 Maggiore 194 " 655 a 461 Como 199 a 414 it 415 Lugano 266 a 288 il —22 Varese 289 li 29 il 210 Iseo 185 a 436 (1 —161 Garda 65 (( 346 11 —281 These depths are the more remarkable if we com- pare them with certain seas. For instance, the English Channel is nowhere more than 50 metres in depth, the North Sea, 60. The original depth of the lakes was, moreover, even greater, because the present bottom is in every case covered by alluvium of unknown, but no doubt consid- erable, thickness. The Lakes of Neuchatel and of Bienne only differ by 1 metre as regards the water-level, but the Neuchatel basin is 60 metres deeper than that of Bienne. The great Italian lakes as shown in the foregoing table descend below, sometimes much below, the sea- level. The lakes, moreover, are in some cases true rock basins. In the case of Geneva, for instance, though the actual outlet is over superficial debris the solid rock appears in the river bed at Vernier only 10 metres below the surface of the lake or 300 metres above the deepest part. The materials brought down by the rivers have not only raised the bottoms of the lakes, but have dimin- IX THE LAKES 155 ished their area by filling them up in part, especially at the upper ends. It is evident that they were at one time much larger than they are now. The Lake of Geneva extended at least to Bex and perhaps to Brieg, that of Brienz to Meiringen, of Lucerne to Erstfeld, the Walensee to Chur, the Lake of Con- stanqe at least to Feldkirch, the Lago Maggiore to Bellinzona, that of Como to Chiavenna. Moreover, the Lakes of Brienz and Thun formed one sheet of water, as also did the Walensee and the Lake of Ziirich. Very slight changes might again greatly enlarge the lakes. For instance, if the narrow outlet of the Aar, somewhat below Brugg, were again closed, a great part of the central Swiss plain would be submerged. The problem of the origin of lakes is by no means identical with that of rivers. We have not only to account for the general depth of the valley — this may be due to running water — but for the exceptional basin of the lake ; running water produces valleys, it tends to fill up and drain lakes. To what then are lake basins due ? It used to be supposed that many lakes were due to splits and fractures. I do not, however, know of any Swiss lake which can be so explained. We may divide lakes into four classes : — 1. Lakes of embankment. 2. Lakes of excavation. 3. Lakes of subsidence. 4. Crater lakes. In many cases, however, a lake may be due partly to one of these causes and partly to another, and for con- venience of description they may be dealt with under eight heads : — 156 SCENERY OF SWITZERLAND chap. 1. Those due to irregular accumulations of drift; these are generally small and quite shallow. 2. Corrie lakes. 3. Those due to moraines. 4. Those due to rockfalls, landslips, river cones, glaciers, or lava currents damming up the course of a river. 5. Loop lakes. 6. Those due to subterranean removal of soluble rock, such as salt, or gypsum. These principally oc- cur in Triassic areas. 7. Crater lakes. 8. The great lakes. 1. As regards the first class, we find here and there on the earth's surface districts sprinkled with innu- merable shallow lakes of all sizes, down to mere pools. Such, for instance, occur in the district of Le Pays de Dombes between the Rhone and the Sa6ne, that of La Sologne near Orleans, in parts of North America, in Finland, and elsewhere. Such lakes are, as a rule, quite shallow. They are due to the fact of these regions having been covered by sheets of ice which strewed the land with irregular masses of clay, gravel, and sand, on a stratum impervious to water, either of hard rock such as granite or gneiss, or of clay, so that the rain cannot percolate through it, and where there is not sufficient inclination to throw it off. 2. Corrie lakes may be thus explained. Let us assume a slope (Fig. 64, a 6 c c?) on which snow and ice (e) accumulates. The rocks and fragments falling from the heights would accumulate at d. Moreover, the ice would tend to form a hollow at c (Fig. 65) where the pressure would be greatest. THE LAKES 157 If subseq jently the snow and ice melted, water would accumulate in the hollow (Fig. 66), and lakes thus formed are common in mountainous districts, where they have a special name — Corries in Scotland, Oules in the Pyrenees, Botn in Norway, Karwannen in the German Alps, etc. 3. A third class of lakes is that due to river valleys having been dammed up by the moraines of ancient glaciers. To this cause are due the Lake of Ziirich (in part), the Lake of Hallwyl, of Sempach, several of the Italian lakes (Iseo, Orta), and many others. In fact, most of Fig. 64. Fig. 65. Fig. 66. Diagrams to illustrate Corrie Lakes. the valleys descending from the Alps have, or have had, a lake where they open onto the Plain. 4. The fourth class of lakes were once even more numerous in Switzerland than at present. As cases of lakes due to rockfalls, I may mention the Torler See, near Ziirich, and the Klon See in Glarus; among those due to river cones, the Sarnen See, and the lakes of the Upper Engadine ; and as instances of lakes dammed back by glaciers, the Lake of Tacul on the Mont Blanc range, and the Merjelen See, which is dammed back by the Aletsch glacier. In our own country the margins of such an ice-dammed lake form the celebrated "parallel roalds of Glenroy." 158 SCENERY OP SWITZERLAND chap. 5. Loop lakes occur along the course of many large rivers. The stream begins by winding in a loop which almost brings it back to the same point. The narrow neck is then cut through and the loop remains as a dead river channel, or "Mortlake." , Again, Avhen an island is formed in mid-channel, one of the side streams is often cut off, and forms a curved piece of standing water. 6. Subsidence lakes as already mentioned occur principally in Triassic areas. The gyjisum or salt is dissolved away in places, and eventually the ground gives way, leaving funnel-shaped hollows. Such a pool was actually formed near the village of Orcier in the Chablais in the year 1860. There had previously been a strong spring giving rise to a stream. Suddenly the ground fell in, forming a pond about 20 metres long and 8 wide. Three fine chestnut trees were engulfed, and the pool was so deep that at 20 metres no bottom was found, nor were even the tops of the trees touched. ^ These hollows are generally small, though in some cases, as for instance the Konigs-See, the Lakes of Cadagno and Tremorgia in the Ticino, they are of con- siderable dimensions. Our Cheshire Meres are mainly due to the same cause. 7. Lakes occupying craters are far from infrequent in Volcanic regions, as for instance in the Auvergne, the celebrated Lake Avernus in the district of Naples, and the Maare of the Eifel. There are, however, no crater lakes in Switzerland. 8. As regards the greater Swiss lakes there has been much difference of opinion. Ramsay and Tyndall maintained that they were rock basins excavated by glaciers. 1 Favre, Bech. Geol., vol. ii. IX THE LAKES ' 159 Mortillet and Gastaldi ^ have suggested that the val- leys were in pre-gUcial times filled with alluvium, and that this soft material has been ploughed away by the glaciers. "That glaciers rub down rocks," says Sir A. Geikie, " is demonstrated by the roches moutonnSes which they leave behind them." That they can dig otat hollows has been denied by some able observers, but that they can do so to some extent at least, seems to be proved by the way in which the ice-strise descend into and rise out of rock basins. " Taking the case of a glacier," says T3rndall, " 300 metres deep (and some of the older ones were probably three times this depth), and allowing 12-20 metres of ice to an atmosphere, we find that on every square inch of its bed such a glacier presses with a weight of 486,000 lbs. With a vertical pressure of this amount the glacier is urged down its valley by the pressure from behind." 2 Indeed, it is obvious that a glacier many hundred, or in some cases several thousand, feet in thickness, must exercise -great pressure on the bed over which it travels. We see this from the striae and grooves on the solid rocks, and the fine mud which is carried down by gla- cial streams. It is of quite a different character from river mud, being soft and impalpable, while river mud is comparatively coarse and gritty. The diminution in the rapidity of motion of a glacier at the sides and near the bottom, which has been some- times relied on as evidence that glaciers cannot excavate, shows on the contrary how great is the pressure. The question has been sometimes discussed as if the ^ Siir V affouillement glaciaire. Atti della Soc. Ital. 1863. 2 Tyiidall, "Conformation of the Alps," Phil. Marj., Oct. 1860. 160 SCENERY OF SWITZEKLAND point at issue were whether rivers or glaciers were the more effective as excavators. But this is not so. Even those who consider that lakes are in many cases due to glaciers might yet admit that rivers have greater power of erosion. There is, however, an essential dif- ference in the mode of action. Rivers tend to regular- ise their b6ds ; they drain but cannot form lakes. As Playfair long ago pointed out,^ a lake is but a tempo- rary condition of a river. Owing in fact to rivers, lakes are mere temporary incidents. The tendency of running waters is to cut through any projection, so Fig. 67. — Diagram to illustrate the Action of Kivers and Glaciers. A, A', hard ridges; B, B', B", softer strata; O, O, slope of running water; D, JO, slope of ice. that finally its course assumes some such curve as that in Fig. 47, from the source to its entrance into the sea. The existence of a hard ridge would delay the exca- vation of the valley ; above it the slope would become very gentle, but no actual basin could be formed ; we should have some such section as in Fig. 67. The action of a glacier is different ; it picks out as it were the softer places, and under similar circumstances basins might be formed above the harder ridges as shown in the dotted lines, D, D. In many of the Swiss valleys the pressure of the ice 1 Playfair's Works, vol. i. ix THE LAKES 161 on its bed must have been very great. The Rhone glacier not only occupied the basin of the Lake of Geneva, but rose on the Jura to a height of 760 metres. The lake is 309 metres deep, so that the total thickness of ice must have been over 1000 metres. The greatest depth of the lake is moreover opposite Lausanne, where the thickness of the ice would be at its maximum. Moreover, the depth in proportion to its size is quite insignificant ; Fig. 68 shows the height of the moun- tains, the thickness of the ice at the time of its great- est extension, while the dark line below gives the 9 960 978 960 300 -m C 111 1 11 lu III!" VI III ' n\ IV'II DIJ \ w !ll Ice. Water-level/ Fig. 68. — Diagram Section along the Lake of Geneva. Tlie dark line shows the relative depth of the water. relative depth of the water, showing that after all the Lake of Geneva is really but a film of water. There are, however, strong reasons against regard- ing glaciers as the main agents in the formation of the great Swiss and Italian lakes ; and Swiss geologists are not generally disposed to accept this as a sufficient ex- planation. They admit that glaciers grind and smooth the rocks over which they pass, but deny that they effectively excavate. The Lake of Geneva, 375 metres above the sea, is over 309 metres deep, and if we allow for the accumu- lation of sediment, its real bottom is probably below the sea-level. The Italian lakes are even more re- 162 SCENERY OF SWITZEELAND chap. markable. The Lake of Como, 199 metres above the sea, is 414 metres deep. Lago Maggiore, 194 metres above the sea, is no less than 655 metres deep. The difficulty thus arising, moreover, is not so much the absolute depth, as the absence of relative height above the sea, so that there would be no sufficient fall to carry off the water. Even if we suppose that the sea came up to Lyons, still the distance from Lausanne being 180 km., the . lake must have been raised 300 metres to give even a minimum fall of 2 per cent.^ In the valley of the Rhone the upper level of the ice had a slight but regular slope. At Schneestock the upper limit was at a height of 3550 metres, at Leuk 2100, at Morcles near St. Maurice 1650 metres. But at Chasseron on the Jura the height is now 1410 metres, at Chasseral 1306, on the Saleve 1330. This gives a slope of 21 to 3 per cent only. Now in the present Swiss glaciers the slope is about 6 per cent. That of the glacier of the Aar, which is the least in- clined, is 5 per cent. No doubt the greater the glacier the less is the inclination at which it can move. Still a slope of 3 per cent would seem quite inadequate. If, however, we suppose that the Alps had a relative greater altitude of say 1000 metres the difficulty would be re- moved, and the glacier would have a sufficient fall. These and other considerations have led gradually to the opinion that while the valleys occupied by the Swiss lakes were mainly excavated by running water, the lakes themselves are due to a change of level which has raised parts of the valleys as compared with the river courses nearer the mountains. Prof. Heim has suggested that the compression which 1 Forel, Le Leman. IX THE LAKES 163 elevated the Swiss mountains and piled, as we have seen (p. 50), more than double the original weight on this portion of the earth's surface, led to the formation of the great lakes. The mountain mass thus concentrated on a comparatively small area would from its enormous weight tend to sink somewhat into the softer magma below, which of course would have had in this respect the same effect as if the surrounding country had risen. The result would be to dam up the rivers and fill the valleys. For instance, in the Lake of Lucerne the bot- tom of the Bay of Uri is almost flat ; it is evidently a river valley which has been filled with water. In fact, speaking generally, the great Swiss lakes are drowned river valleys. The relative subsidence of the mountains is no mere hypothesis. There are, as we shall see, strong grounds for believ- ing that the country round Geneva has been recently raised. The old river terraces of the Reuss can still be traced in places along the valley near Zug. Now, these ter- races must have originally sloped from the upper part downwards, that is to say, from Zug towards Mettmen- stetten. But at present the slope is the other way, i.e. from Mettmenstetten towards Zug. From this and other evidence we conclude that in the direction from Lucerne towards Rappersdorf there has been an eleva- tion of the land, which has dammed up the valley, thus turned parts of the Aa and the Reuss into lakes, and as we shall see considerably changed the course of the river. Again Professor Heim has pointed out that there has been a comparatively recent elevation, even since the commencement of the Glacial period, along a line trav- ersing the Lake of Ziirich. This is shown by the fact 164 SCENERY OF SWITZERLAND chap. that while the lower terraces follow the general slope of the valley, the upper glacial deposits present for some distance a reverse inclination. M. Aeppli in his recent work ^ has described them in more detail. They are seen on both sides of the lake, between Horgen and Wadenschweil on the one side, and between Meilen and Stafa on the other. They do not, however, exactly correspond on the two sides of the lake, because the zone of compression crosses the lake diagonally, com- mencing more to the south on the east side. For the same reason while the compression has on the east side made the terraces slope towards the lake, on the west the slope is towards the hill. This curious fact was very difficult to account for, but is satisfactorily ex- plained by the inversion of the terrace. ■ I had the great advantage of visiting the terraces on the west of the lake under the guidance of Professor Heim, and looking across we could clearly see those on the east side also. Looking to other countries the case of the Dead Sea is very suggestive. From its southern end a long de- pression leads southwards ; it is evident that the Jor- dan once ran into the Gulf of Akaba and so to the Red Sea, and that a subsequent change of level has created the Dead Sea, which has a depth of 396 metres below the ocean-level. The great American lakes are also probably due to differences of elevation. Round Lake Ontario, for instance, there is a raised beach which at the western end of the lake is 110 metres above the sea-level, but rises towards the east and north until near Fine it reaches an elevation of nearly 300 metres. As this terrace must have originally been horizontal, we have 1 Beitr. z. Geol. K. d. ScJiw., L. xxxiv. IX THE LAKES 165 here a lake barrier, due to a difference of elevation, amounting to over 180 metres. The next question which arises is as to the age of the lakes. The valleys are now regarded by most Swiss geologists as pre-glacial, but the lakes themselves origi- nfited after the retreat of the glaciers.^ If these views are correct the larger lakes north of the Alps may be divided into three classes. Firstly, the lakes of the Jura, — those of Neuchatel, Bienne, and Morat, which occupy synclinal valleys. Secondly, those of Hallwyl, Baldegger, Sempach, Greifen, etc. , which are moraine lakes, the dams at the lower ends being moraines. Thirdly, those of Constance, Ziirich, Walen, Zug, Lucerne, Thun, Brienz, and Geneva, which are to some extent indeed dammed up, but in which the lower ends of the valleys have risen relatively, and which are partly at least geotectonic lakes. Dr. F. A. Forel has suggested ^ that this subsidence of the Central Alps also throws light upon the former extension of the glaciers. The present snow line is at a height of say 2600 metres. If we assume the subsi- dence to have been 500 metres (which seems the mini- mum), and suppose that 900 metres have been since removed from the whole surface, certainly no exagger- ated estimate, this would bring the snow down to the present Ime of 600 metres, which would involve a great extension of the Firn, and consequently of the glaciers. He considers that an elevation of 900 metres would bring the glaciers of the Rhone down again to the Lake of Geneva. The theory deserves careful study, but is open to the objection that the Glacial period is no mere local phenomenon, but seems to have affected the whole northern hemisphere. I Penck, Vergletschertmg der Deutschen Aipen. ^ Le Leman, 166 SCENEEY OP SWITZERLAND chap. In considering the great Italian lakes, which descend below the sea-level, one suggestion has been that they are the sites of the ends of the ancient glaciers, and their lower ends are certainly encircled by gigantic moraines. We must, however, remember that the valley of the Po is an area of subsidence and a continuation of the Adri- atic, now partially filled up and converted into land, by the materials brought down from the Alps. The plain of Lombardy is an area of subsidence, and we are tempted to ask whether the lakes may not be the re- mains of the ancient sea which once occupied the whole plain. Moreover, just as the seals of Lake Baikal in Siberia carry us back to the time when that great sheet of fresh water was in connection with the Arctic Ocean, so there is in the character of the Fauna of the Italian lakes, and especially the presence of a crab in the Lake of Garda, some confirmation of such an idea. However this may be, the lower ends of the lakes have been dammed up by glacial accumulations, rais- ing their levels considerably above the rim of the "rock basins." Further evidence, however, is necessary before these interesting questions can be definitely answered. The Coloue of the Swiss Lakes Switzerland owes much of its charm to the lakes, and the lakes owe their beauty in great measure to their exquisite colouring. In this respect they differ considerably : the Lake of Geneva is blue, but most of the Swiss lakes are more or less green, and some brownish. What is the reason of their difference ? The blueness is not due to, though it may be en- hanced by, the reflection of the sky. Pure water is of an exquisite blue. Of all the Swiss lakes the Lake IX THE LAKES 167 of Lucel in the Val d'Herins is perhaps the clearest, and it is of a lovely blue. Various suggestions have been made to account for the green colour of some lakes. The probable explanation appears to be that suggested by Wettstein, and ably supported by Forel,^ namely, that the blue is turned into green by minute quantities of organic matter in solution. Forel took samples of water from several lakes, thoroughly filtered them, but they retained their colour, showing that it was not due to particles in suspension. He then took a block of peat, and infused it in water, thus obtaining a yellow solu- tion. By adding a small quantity of this to the blue water of the Lake of Geneva, he was able to obtain a green water, exactly similar to that of the Lake of Lucerne. He refers as a test case to the sister Lakes of Achen- see and Tegernsee in the Tyrol. The basin of the Ach- ensee is free from peat, in that of the Tegernsee peat mosses cover a large space. The former is a brilliant blue, the latter a lovely green. He concludes, there- fore, with Wettstein, that the bluest lakes are those which are the purest ; while green lakes contain also a certain quantity of vegetable matter, or peat, in solution. This is, however, by no means the only cause to which water owes a green hue. Shallow water over yellow- ish sand is green by the reflection of the yellow light from the bottom. Again, after storms the water is often rendered thick and turbid. After the coarser mud has subsided the finer impalpable particles give the water a greenish hue, which, however, is only temporary, though it may last for some time. Finally, the water is sometimes coloured green in patches by microscopic algse. 1 Le Leman, vol. ii. 168 SCENERY OF SWITZEKLAND chap. But though the blueness of lakes and seas is not owing to reflection from the blue sky, the brilliancy, beauty, and variety of tone and tints, the play of colour to ultramarine and violet, the constant changes and patterns varying with every breath of wind, the life and glory and beauty of the lakes are entirely due to the light of the sun. The Beinb ok Blancfond If on a fine, still day we look down the Lake of Geneva from some neighbouring height, we see the azure blue of the deep water fringed by a clear gray or greenish margin. This is the "Beine" or "Blancfond" where the shallowness of the water renders visible the gray or yellowisli tint of the bottom. Such a shallow fringe or margin encircles many of the Swiss lakes, and may be explained as follows: The waves gradually eat away the bank, giving rise to a small cliff and talus (Fig. 69). The loose stones and sand are gradually rolled downwards, forming a slightly inclined terrace (Fig. 69, K, M') which finally ends in a steep slope. This terrace is known as the Beine or Blancfond. The depth of the Beine depends on that to which the water is agitated by the waves ; it is less, therefore, in shel- tered, and greater in exposed, situations. In the Lake of Geneva it ranges between 1 and 4 metres. It falls into two parts, the inner (^K, C) due to erosion, and the outer (f, ilf) to deposition. The inclination of the outer slope depends on the nature of the materials; the finer they are the gentler it is. The ancient Swiss Lake Villages were constructed on the Beine, and this shows us how constant the level of the great Swiss lakes must have been for many cen- turies or even some thousands of years. Many of the THE LAKES 169 lake villages belong to the stone age, and the stumps of the piles on which they were built still remain. The platforms could not, of course, have been con- structed over water more than at the outside 5 metres in depth, so that during this whole period the level of the lakes must have been practically what it is now. Indeed, the structure of the Beine itself shows that the level must have remained approximately the same for a very long period. CHAPTER X ON THE INTLUBNCE OP THE STRATA UPON" SCENERY The character of Swiss scenery depends mainly on denudation and weathering, modified by the climate, the character, the chpmical nature, the height, and the angle of inclination, of the rocks. The total thickness of the sedimentary rocks has been estimated roughly at 200,000^ feet, and as the whole of this was deposited in seas or lakes and was derived from former continents, we see how enormous the amount of denudation must have been, especially if we bear in mind that much of it has been washed down and deposited, then raised and afterwards washed down again; some of it moreover several times. The principal forces which have disintegrated rocks are (1) Water; (2) Changes of temperature; (3) Chemical actions ; (4) Vegetation. There are few rocks which are not more or less alter- able by, or soluble in, water. It soaks in and filters through innumerable crevices, dissolving some sub- stances, especially when it is charged with carbonic acid, and leaving others. It also acts mechanically, for as it expands when freezing, it splits up even the toughest rocks, if only there are any crevices into which it can enter. In a dry climate, therefore, the slopes will generally be steeper than in a more rainy region. ' Many of the beds however are not represented in Switzerland. 170 CHAP. X IKFLUENCE OF STRATA UPON SCENERY 171 Even in the absence of water, changes of temperature have a considerable effect owing to the fractures which they produce by the successive contractions and expan- sions to which they give rise. These, liowever, though the principal, are by no means the only factors in denudation. The roots of plants, for instance, have a considerable effect, insinuating them- selves into the smallest crevices and, as they expand with growth, enlarging them by degrees. Yet, on the whole, the action of vegetation is conservative. It absorbs much of the rainfall, and the formation of tor- rents is thus greatly checked. Some of the French Alpine districts, and much of northern Africa, have suffered terribly, and in fact been reduced almost to deserts, by the reckless destruction of forests. Different kinds of rocks are very differently affected by atmospheric influences. Siliceous rocks are liable to disintegration by weather; but, on the other hand, the separate grains of sand or quartz are not only insoluble, but offer great resistance to mechanical action. Water, especially if charged with carbonic acid, can dissolve some Silica, but the quantity is insignificant. Calcareous rocks are much more readily attacked. They generally contain some alumina and siliceous nodules, which remain as a reddish clay with flints after the calcareous matter has been removed. Argillaceous rocks cannot be dissolved, but they are in many cases readily reduced to fine particles and then easily removed. They generally contain some calca- reous material, and when this is washed away, pores and hollows are left which let in moisture. Even when compressed into Schists they often yield to the influence of moisture, and if sufliciently saturated sink into the form of mud. 172 SCENEEY or SWITZEllLAND chap. Along the sides of valleys calcareous rocks often pre- sent steep, even vertical faces. (See Fig. 44, valley of Bienne.) Sandstones and Granite are generally less bold, and marly beds assume still more gentle slopes. The behaviour of argillaceous beds is more dependent on circumstances ; if they are fairly dry they bear themselves well, but if they become wet they are very perishable. So varied are the conditions that every mountain, even if the top only is visible, has a character and in- dividuality of its own. "Le profil de I'horizon," says Amiel, " affecte . toutes formes : aiguilles, faites, creneaux, pyramides, obelis- ques, dents, crocs, pinces, cornes, coupoles ; la dentelure s'inflechit, se redresse, se tord, s'aiguise de mille fa9ons, mais dans le style angulaire des sierras. Les massifs inferieurs et secondaires presentent seuls des croupes arrondies des ligues fuyantes et courbes. Les Alpes sont qu'un soulevement, elles sont un dechirement de la surface terrestre. Le granit mord le ciel et ne le caresse pas. Le Jura au contraire fait comme le-gros dos sous le dome bleu." Not one of these varied forms is accidental. Every one of them has its cause and explanation, though we may not always know what it is. The same configuration wiU of course look very dif- ferent from different points of view. What seems like a sharp point is often the end of a ridge. The sedimentary rocks of the Northern Alps generally present one very steep side; and thus sloping away more or less gently (Rigi, PUatus, Bauenstock, Sentis, Speer, etc.), often in a succession of steps which are rendered conspicuous by lines of snow, having therefore what has been happily called by Leslie Stephen a desk-like form (Fig. 84), they present broad, gently inclining plateaux, ending X INFLUENCE OF STRATA UPON SCENERY 173 suddenly in a steep, almost perpendicular, precipice, wh-icli towers like a wall over the valley, such as the Dia- blerets, Wildstrubel, Gadmerfluh, Claridenstock, Todi, Vorab, Balmhorn, Doldenhorn, Bliimlisalp, etc. In such districts still further denudation gives rise to ridges terminating in towers and teeth, sometimes of terrific wildness, as in the Engelhorner, or in the chain of the Gspaltenhorn. The calcareous Alps are also characterised by the numerous terraces, bands, pil- lars, and cornices. The precipices, as for instance on the Jungfrau and the great wall of the Bernese Ober- land, sometimes reach 2000 metres. We might at first be disposed to anticipate that from their hardness and toughness the Crystalline rocks would be less liable to denudation than the calcareous. And in a sense this is true. In consequence however of these very qualities the drainage in Crystalline dis- tricts is mainly superficial ; while in calcareous regions much of the rainfall sinks into the ground and is carried off by subterranean passages. In our own country we know that the chalk uplands, though cut into along the margins by deep combes, are seldom intersected by valleys, and almost all our railway lines leaving London have been compelled to tunnel through the Chalk. So also in Switzerland the calcareous strata form long con- tinuous ridges, of which the great wall of the Bernese Oberland is a marvellous example. Another reason for the extremely bold character of the calcareous mountains is that such strata are extremely stiff, and where argillaceous rocks would gradually bend, they break away and thus give precipitous cliffs. It was at one time supposed that each kind of rock gave its own special mountain form. Such was the view, for instance, even of excellent observers, such as L. V. Buch and A. v. Humboldt. 174 SCENERY OF SWITZERLAND chap. It would, however, be quite a mistake to suppose that particular contours always indicate the same kind of rock. On the contrary, we find the same forms in dif- ferent rocks, and different forms in the same descrip- tion of rock. They depend greatly on the hardness of the rock, and on the angle at which it stands. Thus tower-like forms occur in Granite, Amphibolite, Sand- stone, Conglomerates, Hochgebirgkalk, Dolomite, etc. The desk-like form which is so frequent in calcareous strata (see, for instance. Fig. 70 on the right-hand side) occurs also in some districts of Gneiss or of Nagel- flue, as, for instance, at the Rigi (Fig. 84). On the other hand, the same rock may give a very different landscape. Thus Granite often assumes rounded out- lines, but often also gives wild ridges of teeth and needles. Gneiss summits with gently inclined beds are less steep and less pointed ; while calcareous rocks if hard and steeply inclined assume not only wild but grand outlines. The Eiger is perhaps the finest type of a cal- careous mountain. On the other hand, in any given district similar geo- logical structure will generally give similar scenery. As a rule steeply inclined strata produce bold outlines, while those which are more horizontal give a tamer scenery. Still, where the rocks are very resistant, and denuda- tion has been great, even horizontal strata may give very bold forms ; of this we have a remarkable in- stance in the Matterhorn, a mountain left between two valleys, where the strata are but slightly inclined, and yet owing to their position and hardness give us the boldest and steepest mountain of the whole chain. In districts of the softer rocks we naturally miss the bold, steep precipices, the jagged ridges, and noble peaks. X INFLUENCE OF STRATA UPON SCENERY 175 and must content ourselves with smiling landscapes and gentle undulations. Another reason which affects the landscape in dis- tricts of sedimentary and Crystalline rocks is that the former crumble away more rapidly, and thus more quickly lose the rounded surfaces due to ice action. Thus, as we ascend the valley of the Reuss where we leave the softer strata and enter the district of Gneiss, we also commence a scenery of knolls rounded by ice. In calcareous districts " weather terraces " form a special feature (Figs. 44, 45). They are due to a succession of rocks of different hardness and toughness, so that some strata weather back more quickly and take a gentler slope than others. Crystalline rocks are generally more homogeneous, weather more evenly, and consequently present more regular and continuous slopes. The Bristenstock, for instance, which towers over the Reuss, is a beautiful example. For a height of 2500 metres it presents an unbroken slope at an angle of 36°. Weather terraces are particularly con- spicuous in certain lights, and especially in winter when there is snow on the gentler slopes. Even in summer, however, the contrast of vegetation is often striking, some lines being marked out by luxuriant grass or bushes, while otliers are comparatively bare. On Granite or Gneiss a good mountaineer can go almost anywhere, while in mountains of sedimentary strata he is stopped from time to time by an impassa- ble precipice. On the whole, when seen from a distance, the forms of the sedimentary mountains are more marked, more broken, and, so to say, more individualised. The central Crystalline " massivs " present very dif- ferent forms. The desks, terraces, pinnacles, and cor- nices disappear and we have noble pyramids. The 176 SCENERY OF SWITZEKLAND chap. ridges, moreover, are more jagged and serrated. Fig. 70 shows the contrast of a jagged Crystalline ridge and the desk-like form of the calcareous strata on the right (Hiihnerstock). In the splendid panorama seen from Bern the Crystal- line mountain peaks (Finsteraarhorn and Schreckhorn, Breithorn, Tschingelhorn, etc.) can readily be distin- guished from the calcareous mountains (Bliimlisalp, Doldenhorn, Aletsch, etc.). The difference of charac- ter is also well seen as we ascend the valley of the Reuss from Fluellen to Andermatt. On the whole, the calcareous chaius of the Alps are wilder, the Crystalline grander. Typical Gneiss often gives gentle rounded outlines. Fig. 70. — Ridge of the Gauli. Profile of the ridge from the Bachlistock to the Hiihnerstock, showing the peaks of the granite rock and the desk- like slope of the calcareous strata forming the Hiihnerstock. On the other hand, Sericitic Gneiss and Mica Schists, which often closely resemble Gneiss, show generally great readiness to fracture in sharp, knife-edge ridges, and very wild if perhaps less sublime forms. The Bernese Oberland owes both its great average height and the variety of its scenery to the combination of Gneiss with calcareous strata. The consequence is that it does not form an uniform range, like the Pyre- nees, but a succession of individual mountains, present- ing some of the noblest forms. In this district the Gneiss is inverted over the secondary strata, which it thus serves to protect. The result is that the weather- X INFLUENCE OP STRATA UPON SCBNBEY 177 ing forms of both strata come into play, and thus pro- duce endless variety. Granite is regarded by poets as peculiarly resisting, and it is described as stern, unyielding might Enduring still through day and night Eude tempest shock and withering blight. As a matter of fact, however, Granites, as a rule, are very susceptible of disintegration. Granite mountains tend to gentle, rounded, and massive forms. Rain, and especially water charged with carbonic acid, acts on Granite profoundly. In many quarries where it looks solid enough it will be found to be dis- integrated to a considerable depth, and even changed into a loose sand. This is due to the Felspar ; the alkaline salts of soda and potash being decomposed by the carbonic acid, leaving the Silicate of Aluminium, the Mica and the Quartz. It seems at first inconsist- ent with this that Granite ridges are often peculiarly jagged, but in such cases the Granite is steeply inclined, and the debris are removed as they form. In other oases Granite shows a tendency to weather in fiat, convex shells, and to split vertically in two or often three different directions : it is divided, more- over, into horizontal layers at more or less regular in- tervals, thus forming rhomboidal blocks or pillars. Granite possessing this structure often assumes very bold, wild forms. Protogine, though so similar to Granite, generally gives a different scenery. It breaks up more readily into Aiguilles, and the stratification is more marked. The Mont Blanc range, for instance, which consists of vertically structured Protogine, has a different aspect from the chains which are composed of true Granite. 178 SCENERY OF SWITZERLANP chap. The "Aiguilles" formed by Crystalline Schists, as for instance in the Mont Blanc district, at first sight resemble dolomite peaks. The transverse lines, how- ever, are not continuous, and the summits are even more pointed, though in many cases, as, for instance, the Aiguille de Charmoz, what seems a pointed needle is really a long, narrow crest. The materials are among the very hardest in existence. Hornblend schist is sometimes quite pale, sometimes very dark. It often becomes reddish by decay of the ferrosilicate, so that many mountains of this rock are known as the Rothhorn, Rothfluh, etc. It forms bold, sharp ridges and torn, wild, pointed peaks. Porphyry, though rather rare, forms an extensive bed in the neighbourhood of Botzen, occupying an irregular strip, running from north to south some 40 miles long by 12 wide, through which the outlet of the Adige has been cat. The great rounded walls of dull purplish- red rock, clothed in many places with brushwood, and supporting large upland plateaux of the richest herb- age, produce a scene of singular luxuriance and beauty, especially when their tints are heightened by the glow of the setting sun. Beautiful as they are at all times, there is then something almost unearthly in their splen- dour ; and no one who has not made an evening journey from Meran to Botzen, or from the latter place by the gorge of the Kuntersweg, knows what treasures of colour the Alps can afford. Dolomite is a magnesian limestone. The aspect of Dolomite mountains has been most aptly compared to ruined masonry, and it is often difficult to believe that the summits of dolomite peaks and ridges are not crowned by crumbling towers, castles, and walls built by man. A square columnar formation is characteristic. The X INFLUENCE OP STRATA UPON SCENERY 179 whole of the face shows transverse and vertical marking, the transverse lines running more or less continuously across the whole. The jagged outlines of the crests form a principal feature for their recognition. The outline is usually " embattled," to borrow an expression from heraldry. The colours are marvellously beautiful; cream colour and gray predominate, but not to the ex- clusion of others. In the glow of sunset they are almost unearthly.! The Upper Jurassic gives valleys a very characteristic aspect. It assumes a steep slope of from 40° to 60°. If the inclination is not above 45° it becomes covered with vegetable soil and often clothed with fir ; but the steeper slopes are bare and arid, and are known as Chables or ravieres, giving an aspect of ruin and deso- lation forming often a strong contrast with the brilliant vegetation below. In calcareous districts the surface is sometimes quite bare and intersected by furrows attaining a depth of several, sometimes even as much as 30, feet. A good illustration is to be seen above the hotel at Axenstein on the Lake of Lucerne, where a portion of the rock has been uncovered. Another is at the Kur- haus on the Brunig. RoUier refers to a great erratic on the Lapie of Bon- jean near Bienne, which has protected the rock below it, so that it rests on a flat surface in the middle of the Lapie. The Hohle Stein near Donanne is another case of the same kind. The Karren are extremely barren, but the rock gen- erally contains some small percentage of clay, which is washed into the hollows and supports some scanty veg- etation. 1 C. T. Dent, Mountaineering, "Badminton Library." 180 SCENERY OP SWITZEKLAND chap. The Fly sell gives gentle uniform slopes. The Nagel- flue in the familiar case of the Rigi is an illustration of the desk-like form, with a steep escarpment towards the Bay of Kiissnach and a gentle slope following the inclination of the beds from Rigi Kulm to the Schie- deck. In other cases the Nagelflue gives a very com- plicated relief, sometimes forming mountain knots from which valleys radiate in all directions. Deep gorges, with perpendicular, almost overhanging, bellied walls, and abrupt terminations, also frequently occur in Nagel- flue districts, as for instance to the north of the Lake of Thun, on the Speer, and elsewhere. Glaciated regions present us two totally distinct types of scenery : a central or upper of bare, barren rock with rounded outlines (Fig. 32), and a peripheral ring of debris in scattered heaps and long mounds. These morainic deposits give a peculiar character to the scenery : the country is very diversified and irreg- ular, thrown into confused heaps and depressions, which, as the lower or ground moraine is very impervious, often contain small lakes. They occur especially in well- watered districts, and the rich network of rivers often take very devious courses. Desor has happily characterised such a district as "un paysage morai- nique." The scenery is again affected very much by different strata in consequence of their influence on streams and springs. For instance in a country of hard, impervious rock we have numerous little runnels which gradually unite into larger and larger streams. On the contrary in a calcareous district, especially if fissured, we find, as for instance in parts of the Jura and elsewhere, large districts with very few streams, and here and there copious springs, where the water is brought to the sur- face by some more impervious stratum. A glance at X INFLUENCE OF STRATA UPON SCENERY 181 any geological map will show, for instance, that the districts occupied by the Upper Jurassic rocks are especially waterless, there being many square miles without even the smallest rivulet. The distribution of springs naturally affects that of villages. Thus in several of the valleys of the Jura we find a row of hamlets along the outcrop of the imper- vious Purbeck strata. The influence of different rocks upon vegetation is another way in which they affect the character of the scenery. The principal contrast is between Crystalline and calcareous strata. Cargneule gives fertile pasturage, as do the Lower and Middle Jura owing to the quantity of Marl they contain. The Cretaceous rocks furnish sweet but not abundant herbage, and the Lias is but moderately favourable to vegetation. The Urgonian districts are arid and bar- ren, and can be distinguished even at a distance from the Neocomian, which bears a luxuriant vegetation. Flysch supports a vegetation, vigorous indeed, but of comparatively little value ; the slopes generally bear dry grass and heather, while the flat ground is marshy. Moraines often bear high Alpine plants, not so much from any peculiarity of soil, as because of its coming from the heights. Screes are generally bare from the continuous move- ment, which does not give plants time to grow. ROCKFALLS Falling stones constitute one of the greatest dangers of the Alps. Tyndall was injured, and Gerlach killed by one. Many couloirs cannot be" ascended without much risk, and the ancient passage up Mont Blanc, 182 SCENERY OP SWITZERLAND chap. first discovered by Balmat, has been abandoned for another, longer but safer, route. Many of the steeper valley sides, as, for instance, those between Martigny and the Lake of Geneva, are furrowed by stone streams, which, like those of water, have their collecting ground above, their regular channel, and a cone of deposit below, which, however, stands at a steeper angle than that of a torrent. Many rockfaces have a continuous talus or scree of fallen stones at the base, which takes an angle of about 30°, and in some cases has almost climbed up to the summit. Along the valleys of the Niremont-Pleiades which abut on the Lake of Geneva at Montreux, the debris from the two sides meet in the middle, and attain a great thickness. One of the finest examples is that at the foot of the Diablerets, which rises from 2035 metres to about 2400 metres.^ The Glarnisch is nearly surrounded by rockfalls on its northern and eastern sides. They are mostly of inter-glacial age, and to one of them the Klonthalsee is due. In the debris of rockfalls the edges of the stones re- main fresh and angular ; on many of them the surfaces show marks of blows, rubbing, hollows, and impressions, where they clashed against one another during the descent. They lie in wild confusion, large and small together, from fine dust up to rocks larger than a house. In some cases the originally loose materials have been subsequently cemented together into a breccia. The surface is very irregular, and often contains lakes, as, for instance, at Sierre in the Valais, and Flims on the Rhine. The rockfall of Goldau from the Rossberg which occurred in 1806, which has been figured by Ruskin,^ is 1 Renevier, Beitr. z. Geol. d. Schw., L. xvi. ^Modern Painters, vol. i7. X INFLUENCE OP STKATA UPON SCENERY 183 well seen on the St. Gotthard line, between Lucerne and Brunnen. Even more destructive was that of Piuro (Plurs) in the Val Bregaglia in 1618. After heavy rain a great part of the side of Mont Conto fell suddenly into the valley, and of 2000 inhabitants very few escaped. At Flims (" Ad flumina," so called from the number of springs and streams) the road rises far above the Rhine and passes over an ancient rockfall, the greatest in all Switzerland, far surpassing that of Goldau. It blocked up the valley, thus forming a lake, and the Rhine has not even yet cut completely through it. The debris rise to a height of 700 metres on both sides of the river. They consist mainly of Malm, interspersed however with blocks of Dogger, Verrucano, etc., and fell from the Flimserstein. The fall appears to have taken place between the first and last great extension of the glaciers. As in all rockfalls the surface is very uneven ; and in the hollows are several beautiful lakes. The isolated eminences in the valley below Reichenavi are probably portions of another rockfall. Among other great rockfalls may be mentioned those of Antrona Plana on the 26th June, 1642, which destroyed the Parish Church and many houses, caus- ing also much loss of life : those of the Diablerets in 1714 and 1749, of Montbiel in Prattigau in 1804, and the Dents du Midi in 1835, and that of Elm in 1881. The pretty little lake of Chede, on the road between Geneva and Chamouni, was filled up by a rockfall in the year 1837. Nor must rockslips pass altogether unmentioned. Sometimes the movement is continuoiis, though very slow. In the chains of the Gumfluh, between Chateau d'Oex on the Sarine and the Diablerets, which are composed of hard calcareous rock on which vegetation 184 SCENERY OP SWITZERLAND chap. establishes itself with difficulty, the cone of talus descends slowly towards the valley almost like a river. 1 Again at Soglio in the Val Bregaglia a mass of detritus which has itself fallen from the steeper preci- pices, was for a long time, and probably is still, slowly moving downwards. The firs which grow on it do not stand upright, but cross one another at various angles, some being almost prostrate. The rocks below (Gneiss and Mica Schist) are inclined so that the edges retard the ' movement, which would otherwise be quicker and more dangerous. Theobald tells us that in the summer of 1861 at the time of the melting of the snow, he was on a geologi- cal excursion near the Schwarzhorn in the Grisons, when he gradually became aware of a strange roaring and crushing noise all round him. At first he paid little attention to it, but he at length found that the whole surface on which he stood was slipping down- wards. He escaped as quickly as he could, but the movement continued, and about a quarter of an hoiu" afterwards a great mass, 20 to 30 paces in length, pre- cipitated itself over a precipice. ^ Earth Pyramids Whenever we have a deposit of comparatively loose material with hard blocks, or layers, there is a ten- dency to form earth pyramids, owing to the looser material being here and there protected by a more or less tabular block of hard substance. The most re- 1 Favre and S., Beiti: z. Geol. K. d. Schw., L. xxii. ^ Beitr. z. Geol. K. d. Schw., L. ii. X INFLUENCE OP STKATA UPON SCENEKY 185 markable assemblage of such earth pillars is near Klo- benstein, in the valley of the Katzenbach, near Botzen,i described and figured by Lyell ; that of Useigne in the Val d'Herins is another classical example. ^ Prin. of Oeol.-i vol. i. CHAPTER XI JURA The Jura forms a curve somewhat resembling that of the Alps, trending at first N. and S., and subse- quently S.W. and N.E. It falls into two well-marked divisions, the Tabular Jura and the Folded Jura.^ Tabulae Jtjka The Tabular Jura consists of two comparatively small tracts, one to the N.E., the other to the S.W., which have escaped compression, and consist of approx- imately horizontal strata. In Fig. 71 the ancient mountains of the Black Forest and the Vosges are shown on the N.E. and N.W. Be- tween the two dotted lines is the area of subsidence now forming the valley of the Rhine. The Dinkelberg is a district south of the Black Forest, which has sunk to some extent, but not so much as the Rhine valley. The Tabular Jura of Aargau lies south of the Din- kelberg, and the Elsgauer Tabular Jura south of the Vosges. Between them, south of the Rhine valley, the Jura is thrown into a succession of folds. The ancient crystalline rocks of the Black Forest and the Vosges are probably continued under the Jurassic strata to the 1 Miiller, Seitr. z. Geol. K. d. Schw., L. i. 186 3VRA 187 south, and as Miiiliberg suggests, may have protected them from being folded and contorted as they have been further to the south. It is interesting as confirm- ing this view that the horizontal character of the strata ceases opposite the sunk area of the Rhine valley, and the foldings there reach northwards to the edge of the valley. At the line of contact of the " Tabular Jura " with the Folded Jura, the latter are generally thrust more /. BiirgetitaU. IV Buehertf V. Movilia m.P Section across the WannenfluTti After MUhibery. Lias . Dogger Towen „ middlA „ upper Malm lowen uppen Miooen0. Fig. 73. — Section across the Wannenfluh. clearly visible in the Jura, is frequent also in the Alps, and indeed in folded chains generally.. A glance at any map will show that the Jura is a suc- cession of hills and valleys, running approximately S.W. and N.E. These ridges and depressions are mainly due to compression, and to the consequent undulations of the strata, as shown by Fig. 74, giving a section from N.W. to S.E. a little south of Porrentruy, near the remarkable turn of the River Doubs and crossing both stretches of the river. It will be seen that the valleys 190 SCENERY OF SWITZERLAND are synclinals, and that in the valleys the action of water has been but slight. The next figure (75) represents a section across the Mont de Moutier, from the vaUey of Delemont to that of Moutier, and we see that some of the highest ground is a synclinal. Fig. 76 gives a case of two neighbouring valleys, one CK dii tfonterri on da Lomoat Selente Gli. da Clos da Doubs Epaavilliers St,Brais Fig. 74. — Section across the Clos du Doubs. of which (Le Locle) is a synclinal, the other (Entre- Deux-Monts) an anticlinal. In both the cases above mentioned the configuration of the surface — the arrangement of hills and valleys, the direction of rivers and mountains — corresponds closely with the geological structure. Fig. 77 represents a section of the Vuaclie. It will 7, de Selemoat Ch. de.VeUerat LeUout ■H. de Uoutier V. de Uoatier Fig. 75. — Section from the Valley of Delemont to that of Moutier. be seen that the Vuache is the half of an anticlinal, the western part having subsided about 1000 m. The Rhone runs along the fault. In this case the fault is nearly vertical, but in others one side is thrust more or less over the other. In the Jura, faults generallj', but not always, betray themselves on the surface. The Saleve (Fig. 78), which forms such a conspicu- JURA 191 ous object at Geneva, is an arch, fractured at the sum- mit, and steeply inclined to the N.W. While river valleys, being due mainly to erosion, slope to one end, the valleys of the Jura are so en- tirely the result of geological causes that they are sometimes horizontal, or even lowest in the middle, Entre-deiix-Afouts Combe de Monterban N.W. Fig. 76. — Profile of the Valley of Locle. S.E. and in several cases closed at both ends. The result is that they are often dry valleys, or contain streams running from the two ends towards the centre. Thus between Biel and Delemont we have the Val de St. Imier, in which the Suze, running to the E., meets the stream which comes down the Combe de Pery, and the two together find an exit through the T/-. Rocher (blc'az rnto-Monts t/o. (Ituin) >»"'■ Rhone Vuaoho Glialct 3080 fi. delaBalmo ™~ 2557 n. F19. 77. — Section across the Vuache. Cluse de Pery to Biel. A little north is the Val de Tavannes, where again two streams, one from the N.E., and the other, the Birse, from the S.W., meet at Court and find an exit northwards by Moutier to Delemont. The valley of Delemont itself is another case. Two streams, one from the east, another, the Some, from 192 SCENERY Ol!" SWITZERLAND the west, meet the Birse near Delemont, and run through another cluse to the N.E. The Jura is thus crossed by four principal trans- verse valleys or cluses. The longitudinal valleys were probably filled at one time by MoUasse, and some perhaps formed lakes, as, for instance, the flat plains near Pontarlier, Delemont, the Val St. Imier, etc. Between Delemont and Soleure are several ridges, which are cut through by the " cluses " of the Birse and the Some. If we imagine these "cluses" abolished, the result would be to form lakes; these would gradually fill up, and event- ually run over where the "cluses" now are, which would thus be re-excavated. This throws light on the cases, not otherwise easily explicable, where in neigh- bouring and parallel valleys the streams run in opposite directions. The valley of Etraches, for instance, N.E. of Pontarlier, runs parallel to that of the Doubs, but the Etraches runs from N.E. to S.W., the Doubs from S.W. to N.E. Nay, the Doubs itself, after running north-eastward to St. Ur- sanne, between rocks 250 to 300 metres high, makes an JURA 193 extraordinary turn. Its course so far has been in the main to the N.E., but at St. Ursanne it turns to the W.S.W., enclosing a higla ridge (Fig. 74) known as the Clos du Doubs. The valley of the Rhine from Basle northwards is of comparatively recent origin, being due to a subsidence Rhein numngea Hein-Bassl 3835ft. bdoivseilwel Pig. 79. — Section across the Rhine Valley. which has separated the Black Forest from the Vosges. Just south of Basle the anhydrite beds which at Bet- tingen are 400 metres above the sea-level, have sunk at Hiinningen to 600 metres below it, a drop of 1000 metres in about five miles. At Basle the section is as in Fig. 79. Further north the sinking is more profound, and the strata are fract- ■w. Basel Vcttsteintrucke _,. ,,,■■, Eisenbaiinbnicke E. Donili Horn Junldiolz yrflen Fig. 80. — Section across the Rhine Valley at Basle. ured (Fig. 80). At Kandern the depression amounts to 1500 metres. The sinking of the Rhine valley near Basle was no doubt a slow process. It probably began in the Glacial period, before which time the whole drainage of the country must (see ante, p. 147) have been entirely dif- ferent from the present. 194 SCENEKY OF SWITZERLAND chap. The eastern boundary of the Rhine valley subsidence is apparently continued along the cross line of Miimlis- wyl Balstall. The downthrow of the fault is here also to the west. Again the western boundary of the Rhine valley, though this is more uncertain, may perhaps be correlated with the cross valleys which pass by Delle, Porrentruy, and St. Ursanne, continuing possibly by Sonceboz to Biel. The selection of Pontarlier for the line of railway has been determined by one of the geological events which has most profoundly affected the chain of the Jura. The displacement, commencing in the direction of the valley of the Lone, and passing through it to the eastern end of Mont Tendre, has been utilised by rivers, roads, and railway lines. It passes nearly due S.N., and all the anticlinal and synclinal folds on the two sides of the line show a dislocation, sometimes amount- ing to 2 or 3 km. The Jura is very poor in rivers and streams. It con- sists mainly of calcareous strata, often much fissured, so that the rain sinks into the ground and reappears often in copious springs — named from one of the most celebrated " sources vauclusiennes " — where the water is brought to the surface by some more impervious stratum. In several cases the disposition of the ridges and the character of the rock is such, that the streams have no natural issue, and after a longer or shorter course under ground, reappear at some distance. Thus the Orbe commences in a closed valley. The upper part, or Vallee de Joux, is double, one branch being without any river, except a little streamlet which runs into the Lake of Ter. The southern is traversed by the Upper Orbe which falls into the Lake of Joux, and its contin- uation, the Lake of Brenet. Neither of these has any « JURA 195 open outlet, but the waters escape by an underground passage, and reappear above Vallorbes. This had long been suspected, but was eventually proved in 1893 by M. Picard, who poured in some fluorescine, which after the lapse of 30 hours reappeared in the source of the Orbe. Again the valley of La Brevine is a synclinal of Cretaceous rock, surrounded by Jurassic, and entirely closed. The waters escape through several swallow holes or "emposieux." These, however, sometimes get choked and the valley is flooded. It has been suggested, as already mentioned, that before the sinking of the Rhine valley at Basle, which opened a new route to the north, it belonged to the river system of the Danube ; there is also some ground for thinking that at a subsequent period it continued its course W.S.W. to the Saone, and that the valley of the Doubs below St. Ursanne is in fact an old bed of the Rhine. This interesting point, however, can only be determined by further evidence. The southern limit of the Jura forms the great mountain wall, which, from the Lake of Geneva north- eastwards to Bern, Freiburg, and Aarau, may be seen stretching along the north, without a break, from the Fort de I'Ecluse, where the Rhone crosses the Mont Vuache, to Montricher near La Sarraz. Some districts of the Jura have suffered greatly from the reckless destruction of forests, as, for instance, parts of Mont Tendre, whose dry and barren slopes were once clothed with luxuriant vegetation. It is unfortu- nately becoming evident that much arable land and pasture which, at great labour and expense, have been formed out of the primeval forest, will, with perhaps even more, have to be reafforested again. The Jura Mountains contain several interesting caves, 196 SCENEEY OF SWITZERLAND often associated in popular traditions with the fairies, as the Temple aux Fees near Longeaignes, the Grotte aux Fees near Vallorbes, the Beaumes de la Cote aux Fees, etc. The Grotte de Remonot on the Doubs was long used as a village church. Near Moutier a crack in the Upper Jurassic beds, which was exposed in preparing the founda- tion for a church, was found to contain many bones of quadrupeds belonging to the Eocene period, including three species of Palao- therium. Similar fissures contain- ing Eocene fossils have been met with at Egeriingen, Ober-Gosgen, and elsewhere, showing that dry land existed here during the Eo- cene period.^ The celebrated asphalt of the Val de Travers (Fig. 81) comes mainly from Urgonian strata. The val- ley is a synclinal, bounded, how- ever, on the S.E. by a fault, which brings the more recent strata, from the Portland Beds to the Mollasse, directly against the Malm. As already mentioned, during the Glacial period the grand sheet of ice which spread over the whole Central plain of Switzerland, rose to a great height on the slopes The glacier even rose over more than one of the Jura. of the cols, and streamed into the inner valleys, as, foi 1 MuUer, Beitr. z. Geol. K. d. Schw., L. i. XI JURA 197 instance, by Romainmotier into the Val de Vaulion. The Val de Travers has long been celebrated for the number of erratic blocks which it contains. In many- places the rocks are ground and polished by the glac- iers. The Rhine at Basle runs on a bed of gravel 30 metres at least in thickness, and the hills on each side are capped -with a yellow, fine, sandy marl known as " loess " up to a height of 100 metres. ^ Most indeed of the valleys were once much deeper than they are now. The bottoms are filled up with gravel and alluvium, indicating the presence of bars which are now covered up. The alluvial deposits often attain a great thickness. Near Travers a pro- posed railway bridge had to be abandoned, from the difficulty of obtaining any sufficient foundation.^ Lake of Neuchatbl The Lake of Neuch^tel is about 24 km. in length, and 6 in breadth. It is 432 metres above the sea and 153 in depth. Unless therefore the gravel beds of the Aar are 500 feet deep it is also a rock basin. It is sur- rounded by marshes which used to cover 50,000 acres, but a good deal of the area has now been drained. The Lake of Neuch&tel and of Bienne at one time formed a single sheet. Indeed, the former lake ex- tended from Orbe on the west to Soleure on the east. The basin is formed by one, or rather two, of the longi- tudinal Jura valleys. I say two because a ridge of Marine MoUasse commencing at the hill of Chamblon near Yverdun, runs along the centre of the lake, forms the Jolimont between the Lake of Neuch^tel and Bienne, 1 Miiller, Beitr. z. Geol. K. d. Schw., L. i. 2 Jaccard, Beitr. z. Geol. K. d. Schw., L. vi. 198 SCENERY OP SWITZERLAND chap, xi and continues along the centre of the Lake of Bienne, forming a ridge over 400 feet in height, and appearing above the surface as the Isle de St. Pierre. In fact, if the level of the water was reduced, the Lakes of Neu- chatel and Bienne would each be resolved into two narrow lakes ; while if the water rose they would form a single sheet with the Lake of Morat. CHAPTER XII THE CEKTKAL PLAIN To the S.E. of the Jura is the great Central plain of Switzerland, which is a plain however only in con- trast with the mountains by which it is surrounded, and in other countries would be regarded as an ele- vated hilly region. Thanks to its geological and cli- matic conditions, it is one of the richest and most genial parts of Europe. It extends in a S.W. and N.E. direction from the Lake of Geneva across that of Constance to Wiirtem- berg, and has an average width of about 30 miles. It is mainly formed of Miocene strata known as MoUasse; usually divided into — (1) Lower Fresh- water MoUasse ; (2) Marine MoUasse ; and (3) Upper Freshwater MoUasse ; which, however, according to Kaufmann were in some cases being deposited simulta- neously ; no doubt there were several alternations of sea, marsh, and freshwater. The MoUasse attains an unknown thickness. In parts of Vaud the upper beds alone reach over 1000 metres. In fact, during the Miocene period, the country be- tween the rising Alps and the Jura was a basin occupied sometimes by the sea, sometimes by a great lake and then by the sea again. The rivers from the Alps brought down boulders, gravel, and sand, gradually filling up the hollow, depositing the largest boulders at 199 200 SCENERY OF SWITZERLAND chap. the foot of the mountains and carrying the finer mate- rials further into the plain. The water escaped first perhaps by the Danube ; there is some reason to believe that at one time it flowed by the valley of the Doubs to the Mediterranean, and lastly through Germany northwards, carrying the finer materials to build up the plains of Belgium and Holland. Then came a period of cold — the Glacial period — when rivers of ice gradually descended from the moun- tains, filled up the valleys, and eventually covered the whole of the lower country with a great sheet of ice. The MoUasse consists of beds of sandstone, marl, and, especially as we approach the Alps, of a coarse gravel known as " Nagelflue," which is often cemented so as to form a hard conglomerate. The pebbles are often crushed, sometimes compressed, and the sandstone often shows ripple marks, like those of our present sea shores. Seams of coal occur throughout the iloUasse ; they are, however, not of any considerable extent, nor of good quality, and are generally very thm, not exceed- ing two feet, and rarely more than a few inches. The character of the jMoUasse in fact differs greatly in different localities, which no doubt indicates varj-ing conditions of deposit, rather than difference of age. The beds are more compact towards the south and become looser in texture, more sandy and marly as they approach the Jura. Fossils are rare in the Lower Freshwater JMoUasse. Still there are some places in which they occur. The Nagelflue is abnost without fossils. In the Marine jNIoUasse several hundred species have been determined, mostly marine shells. Remains of land animals occur, however, in the freshwater beds, including a ^lastodon, two species of Rhinoceros, the Dinotherium, etc. xn THE CENTRAL PLAIN 201 The Upper Freshwater MoUasse is much richer and contains the celebrated locality of Oeningen, near the Lake of Constance, where, in strata evidently deposited in a shallow and quiet lake, have been found the re- mains, beautifully preserved, of no less than 1000 spe- cies of insects, about 400 plants, and many vertebrates. , At the close of the MoUasse period the great Swiss plain must have been nearly horizontal, but its elevation above the sea was probably not entirely uniform, and some inequalities were thus produced. The present hills, however, are mainly due to un- equal erosion ; the hard Nagelflue especially has been able to resist the destructive action of time and weather. Towards the south boundary the MoUasse is thrown into two well-marked arches, separated by a synclinal line, marked blue on the Swiss geological map. The anticlinal line runs south-westwards from Bava- ria to the valley of the Rhine, a little south of Bregenz, on the Lake of Constance, then to the Lake of Ziirich, passing along the Obersee to Uznach, then across the Lake of Zug at Oberwyl, so to Lucerne, bends sharply south nean Schangnau, crosses the Aar near Kirchdorf, by Guggisberg on the Sense to Lausanne, and finally in a more accentuated form gives rise to the Mont Saleve (Fig. 78), south of Geneva, where the arch is broken and the Jurassic and Cretaceous strata become visible. This great anticlinal has a length of not less than 370 km.^ At its southern limit the Nagelflue appears, though this is not yet absolutely proved, to be in some places turned over on itself, so that we should in this case have a repetition of the conditions of the Jura (see p. 187) ; nearly horizontal strata to the north, then a series of folds, becoming more and more accentu- iFavre, liech. Oeol., vol. i. 202 SCBNEEY OP SWITZERLAND chap. ated to the south, and finally turned over at the south edge. To this, however, I shall refer again in the next chapter, and will here only observe that it will account for the enormous thickness of the Nagelflue at the Rigi; and also for the want of conformity between the strata, where the Nagelflue and Cretaceous strata meet, as, for instance, at the Vitznauerstock on the Lake of Lucerne. The rivers are now mostly cutting into the old river terraces, and deepening their beds. The elevation of the Alps, as already mentioned, commenced during the Eocene period, but was much more active during the Miocene. The last period of compression and folding was later than the Miocene period, for we find the whole series of sedimentary strata from the Verrucano to the Mio- cene folded together. Between the Alps on the south, the Jura and the Black Forest on the north, the great plain of Switzer- land was tuider water and received the material brought down by torrents from the rising mountains. These de- posits, forming the Nagelflue, consist of coarse agglom- erates and gravels. The pebbles of the Nagelflue are often more or less flattened, and such pebbles are frequently arranged somewhat like the tiles of a roof, so as best to stand the current. They therefore indicate the direction of the streams, showing them in general to have run from S.E. to N.W. They are larger, near the Alps, as for instance at the Rigi and the Napf; and get gradually smaller to the north. Exceptions may no doubt be found, and along the Rhine the gravels contain some large blocks and pebbles of Jurassic limestone. These, however, belong to the Black Forest, and haVe come from the north. XII THE CENTRAL PLAIN 203 Dr. Friihi has made a careful examination of the pebbles forming the Nagelflue. Many come from the neighbouring Flysch. Of many the origin cannot be determined. Pebbles, for instance, from the Flysch and the Lias are in many cases indistinguishable, unless indeed they contain fossils. These are unfortunately very rare. Neither Riitimeyer nor Frlih, in spite of most careful search, have found any fossils in the great mass of Nagelflue forming the Rigi. Heim, however, has met with fragments of Triassic corals, and in other districts fragments of Belemnites, and such pebbles cannot belong to the Tertiary period, Belemnites being then already extinct. It is remarkable that many of the pebbles of the Nagelflue seem to be exotic, that is to say they do not belong to rocks found in the neighbouring mountains. We find scarcely any blocks or pebbles of the Granite, Gneiss, and Crystalline schists which now form the central mountain range of the Alps. Amphibolite, Ser- pentine, Verrucano, and other rocks which we should have expected to find, seem to be entirely absent. At that time, however, these Crystalline rocks were cov- ered to a great depth by the sedimentary strata. Some of the pebbles indeed do not agree with any rock now found in or near the Alps. It has, however, been sug- gested that some of these may really have been derived from the Alpine rocks, but before the enormous pressure had brought them into their present condition. The Nagelflue is evidently a gravel formation — an enor- mous cone deposited at the northern edge of the Oligo- cene and Miocene Alps. The sources of certain pebbles can, however, be ascer- tained with great probability, and Friili concludes that 1 Neue Denkscliriften, 1890. 204 SCBNEKY OF SWITZERLAND chap. the rivers came from the S. and S.E. The watershed was then further south than it is at present, and he believes that the rivers drained not only the nearer Alpine districts, but the Voralberg, the Grisons, North Tyrol to beyond Botzen,.the Val Tellina, and the north of Italy, even to the Lake of Lugano and of Maggiore. The Middle Rhine", Reuss, Inn, etc., extended consider- ably further south. Several of the smaller streams, such as the Carassina, belonging to the Val Blegno, the Forno and Albigno and upper waters of the ]Maira, which now run into the Val Bregaglia to Lombardy, still show by their direction and their terraces that they originally belonged to the river system of Swit- zerland. "The pebbles of the Nagelflue," says Bonney, "indi- cate that this river, instead of flowing as the Reuss now does for the greater part of its course over Crystalline rocks, was then engaged in removing the overlying sedimentaries, and had only here and there cut down the Granitoid Gneisses and Schists."^ Glacial Deposits Over the Tertiary strata lie vast masses of glacial deposits which increase in thickness as we approach the Jura, and cover the whole district with the exception of a few of the highest parts, as for instance the district of the Napf . These deposits can be traced from their extreme limits at Lyons, high up on the Jura, and along the Aar, right up to the modern glaciers. ^loreover, the char- acteristic rocks retain the same relative position. Many of the rocks and stones which it brought down are found ^ The Ch-owth and Sculpture of the Alps, Tyndall Lectures, 1888. XII THE CENTRAL PLAIN 205 in different localities', but some are confined to special districts. Guyot ^ specially mentions the Puddingstones from the Dents de Morcles, the white Granite of the Upper Valais and the Galenstock, the Euphotides of the Saas valley, the Arkesines of the AUelin glacier and the Val d'Herens, and the Protogine of the Mont Blanc range. These do not mix, but occupy the same relative positions at the end of the ancient glacier : the Puddingstones of the Dents de Morcles at Guggisberg; the Upper Valais rocks between Schwarzenberg and Koniz (near Bern) ; the Euphotides at Bern and Bourg- FiG. 82. — Section of the Valley of the Aar. dorf ; the Arkesines at Seeberg ; and the ]\Iont Blanc Protogine at Aarwangen. I have already indicated the borders of the great glacial sheet (^ante, p. 99), and, referred to the reasons long ago brought forward by Morlot for believing that the Glacial period was not one of continuous cold, but that it was interrupted by more genial periods. Fig. 82 represents a section across the valley of the Aar, from Leuggern to Klingnau, a short distance above Coblenz. It is a general character of the upper terraces to be capped by loam or "loess," the deposit of ancient floods before the present river valleys had been cut down to their present depths. Most of the river valleys originated before the Glacial period, but the main erosion seems to have taken place between the first and second ice ages. That they were 1 Bull. iSoc. Sc. Nat. Neufchd.tel, vol i. 206 SCBNEKY OF SWITZERLAND chap. occupied by glaciers during the second and third Glacial periods (see map, p. 83) is proved, as already men- tioned, by the existence of numerous terminal moraines crossing the valleys, and lateral moraines lining the hills along the principal river valleys; as for instance the Aar, especially from Thun to Bern, the Suhr from Sempach to Wittwyl, the Aar from the Baldegger See to Lenzburg, the Reuss from Klein Dietwil below Lu- cerne to Mellingen, the valley of the Limmat from Rapperschwyl, on the Lake of Ziirich to near Baden. Besides the actual moraines and the erratic blocks, the glaciers as they retreated, and the floods arising from the melting of the ice, left great masses of so-called "Diluvial" gravels, which occupy much of the valley bottoms, not having even jet been completely re- excavated by the rivers, and as we approach the Jura even form the hills, the valleys being occupied by com- paratively recent river deposits. Thus the river Lorze runs on this gravel from the Lake of Zug as far as Baar : at Lucerne the gravel has been pierced to a depth of 30 metres without reaching the bottom ; in several places it attains a thickness of even 60 metres.^ The River Langeten near Roggwyl sinks almost entirely into the gravel, so that it disappears except in very wet weather, rising again in several strong springs a little further down the valley. The surface of the gravel beds is very irregular, and often gives rise to small lakes, as for instance the Mauensee, Bibersee, Finster See, Rothsee, etc. , Several of the present peat mosses were formerly shallow lakes of this character. The Baldegger See and Hallwyler See are separated from one another by this Quaternary gravel, which in- deed has so much raised the bed of the whole valley of 1 Kaufmann, Beitr. z. Geol. IC d. Schw., L. xi. XII THE CENTRAL PLAIN 207 the Aa, that the bottom of the Baldegger See is at the same level as Lenzburg many miles down the valley. ^ Round the Lake of Geneva, especially on the south side, biit also elsewhere, as for instance round Aubonne, the glacial deposits attain a great thickness. The ravines, though deep, are excavated altogether in them, and rarely penetrate to the MoUasse. They are more- over very impenetrable, as shown by the great detour which they compel the Versoix to make on its way to the lake. To these glacial deposits the lowlands of Switzerland owe much of their great fertility. Kaufmann^ and Gremaud^ attribute much importance to these deposits in determining the present courses of the rivers. They point out that while some compara- tively large streams such as the Sihl run in narrow valleys, others such as the Suhr occupy much wider ones, out of all proportion to the water supply, and the size of which they account for by glacial action, espe- cially as these wider valleys occupy just the courses of the ancient glaciers. For instance the Rohnthal runs almost from the lower end of the Lake of Sempach westwards to Scholz on the River Wigger. This broad valley is drained by a little stream, the Rohn, and instead of narrowing upwards, retains almost its full width. A little to the north again is the valley of the Hurnbach, which presents very similar characteristics. Kaufmann explains these features by suggesting that the glacier which came down the valley of the Suhr was obstructed by the hill of Wohlen below the Lake of Sempach, and broken up ; one branch passing down the present valley 1 Kaufmann, JBeitr. z. Creol. K. d. Schw., L. xi. ^ jftj^. 8 " :i;tudes sur les yallges de Fribourg," JBuU. Soc. So. Nat., 1888. 208 SCENEEY OP SWITZERLAND chap. of the Suhr, another down that of the Rohn, while a portion of the ice surmounted the hill and continued in a direct course down the valley of the Hurnbach. The pressure of the ice caused by this obstacle may possibly account for the depression now occupied by the Lake of Sempach. The valley of the Bienz, to the west of the Reuss, which is out of all proportion to the size of the present stream, was perhaps occupied by the Reuss in ancient times. The valley contains several moraines, especially at Othmarsingen, where evidently for a considerable time was the head of the glacier, and below which the valley alters its character, becoming much narrower. Another " dead " valley leads from the Aar at Wild- egg, below Aarau, to Mellingen in the A-'alley of the Reuss. It probably marks the ancient bed of the Aar before that river had acquired its present course through the Jura north of Lenzburg. Gremaud has subsequently called attention to other similar cases. The Kleine Emmen rises north of Interlaken and has a well-preserved old valley across the plateau to the Aar at Aarburg, but has now abandoned its old course at Wiggern, and turns sharply round to the east, following a trough which carries it to the Reuss below Lucerne. The river system round Bern is also curious and in- teresting. From the direction of the Upper Sense the natural course of the river would be by Wangen to Bern, and along the valley of the Urtenenbach to the Aar valley below Soleure. In fact there is here a broad valley, apparently once the bed of a considerable river. At present, however, it is occupied by three streams. In the upper part, by the Sense itself, which, however, near Thorisch turns at a right angle to the east and falls into the Sarine. Below Thorisch is a XII THE CENTRAL PLAIN 209 small brook which falls into the Aar near Bern, and turning at a right angle also joins the Sarine. Lastly, the lower part of the valley is occupied by the Urtenen- bach, which joins the Emmen and falls into the Aar below Soleure. It is clear indeed that there are many dead valleys which have once been occupied by rivers, but which are now dry; such as the Klettgau between Schaff- hausen and Basle, which was probably once the course of the Rhine, or perhaps of the Aar; the Glatthal, between the Upper Lake of Ziirich and the Rhine at Kaiserstuhl, which was probably one of the beds of the Limmat; the valley from Oerlikon, by Katzensee to Wettingen, which was also once occupied by the Lim- mat. In some cases the rivers have been forced to change their courses by the enormous masses of glacial deposits. Thus the Sihl was probably cut off from the Lake of Ziirich, and compelled to adopt its pres- ent course parallel to the lake, between the Albis range and the great lateral moraine which forms the low ridge of hills along the west side of the lake. The Aar again appears to have been excluded from its old course down the Gauthal by the moraine at Soleure, and driven to excavate a new bed in the MoUasse.i It is interesting that these deserted valleys not only contain thick deposits of river gravel, etc., but also show the usual terraces along their sides. The remarkable case of the Venoge has been already described {ante, p. 148). The Aar at Aarberg and Schinznach, the Reuss at Miilligen, and the Limmat at Baden, have sawn their way through Jurassic ridges. The Sarine cuts through 1 Du Pasquier, Beitr. z. Qeol. K. d. Schio., L. xxxi. y 210 SCENERY OP SWITZERLAND chap. several mountain ranges.^ If these had risen more rap- idly than the rivers could cut through them, they must have formed lakes, and it is even possible that for a time such lakes may have existed. It is clear then that the courses of the ancient rivers were in many cases very different from those of the present day. But although on the whole the trend of the rivers is simple and uniform, there are not a few cases, as for instance in the north of the Canton of ,Vaud, and south of Fribourg, where the courses of the rivers are far from easy to understand. Gillieron points out that the character of the Flysch which forms the district makes it difficult to distinguish the structure of the mountains, and that it is impossible at present to form any idea as to the original relief. The arrangement, both of the Marine and Fresh- water MoUasse, makes it probable that the drainage of Switzerland was then eastwards by the valley of the Danube to the Black Sea. The openings which now carry the waters of the Valais westwards to the valley of the Saone and so to the Mediterranean, and of the Aar and the Rhine by Brugg and Basle to the North Sea were not yet in existence. The Tertiary strata of France and Germany have no connection with those of Switzerland, and were evidently separated by dry land — by the Jurassic chains. The subsidence which has given rise to the Rhine valley from Basle northwards, and the erosion of tlie Rhone valley at Bellegarde, are therefore long posterior to the period of the MoUasse. The Rhone was eventually shut off at Mormont, between the Lakes of Geneva and Neuchatel, the Aar at Baden, while the subsidence between the Vosges and 1 Musy, " Disc. pron. k I'ouv. de la 74' sess.," Ann. Soc. Helv., Fri- bourg, 1891. xn THE CENTEAL PLAIN 211 the Black Forest opened a way for the Rhine to the north. The rivers then adopted their present courses, the Rhone to the Mediterranean, the Aar and the Rhine to the North Sea, thus depriving the Danube of a very- large part of its original territory. It is evident that these changes must have taken a long time, though from a geological point of view they are very recent. The evidence of many changes in the course of the Rhine from Eglisau to Coblenz indicates this, as well as the fact that neither the Rhone, the Rhine, nor the Aar have yet been able to regularise their beds. They are divided by ridges into distinct sections with different inclinations. The result of the general inclination of the plain is that the Lower Aar runs at the foot of the Jura, and that a succession of rivers, the Upper Aar, Eramen, Suhr, Aa, Reuss, Limmat, Glatt, Toss, and Thur, at approximately equal intervals, run from S.E. to N.W. into the Aar and the Rhine. But while it is clear that the rivers formerly ran at a much higher level than the present, and have excavated their valleys, the great deposits of river gravel, etc., show that the valleys were at one time even deeper than they are now, and were subsequently filled up to a certain height. The present period is again one of erosion. The rivers are at present deepening- their beds, but in the lower portions of their course have seldom cut down to their former level, though they have done so in some places, as, for instance, the Lim- mat below Baden ; but in other cases where they appear to have done so, for instance the Aar at Brugg, and the Rhine near Irchel, Kaiserstuhl, Laufenberg, and Rhein- felden, though the present bed is cut into the rock, this is due to a change in the course of the river. The old river gravels at the Brugg railway station, and south of Laufenberg, are much deeper than the present river. CHAPTER XIII THE OUTER-ALPS The outer chain of the Northern Alps consists of Eocene and Secondary strata thrown into a series of folds, and running from S.W. to N.E. They extend far into Austria on the east, forming the north part of the Voralberg, and into Savoy on the west, but so far as Switzerland itself is concerned they commence in the valley of the Rhine at the east end of the Lake of Con- stance, form the Sentis Mountains, and the Churfirsten over the Walensee, extend by Einsiedeln and Schwyz to the Lake of Lucerne, stretch away to the Lake of Thun, and then form a grand curve with its convexity northwards, reaching almost to Fribourg, and so to Vevey and Montreux on the Lake of Geneva, to the south of which they extend into the Chablais and Savoy. They form a complicated net-work, which on an ordi- nary map shows no regular arrangement ; the configura- tion of the surface has been greatly affected by folds, fractures, faults, and denudation, and the structure is in many places still an enigma.^ They are as a rule more folded and contorted than the Jura, but less so than the central chains. The arches, however, though less compressed are'-more often fractured at the summit,^ pointing to a difference of iSohardt, " Struct. G60I. des Pre-Alpes," Bib. Univ., Geneve, 1892. ''Favre and Sohardt, Beitr. z. Geol. K. d. Schw., L. xxii, 212 CHAP. XIII THE OUTER-ALPS 213 conditions. Possibly the explanation may be that the compression was more rapid or nearer to the surface. The Eocene strata often lie in troughs between Juras- sic and Cretaceous mountains, and it has been supposed by some geologists that they were deposited in bays or iiords. It seems, however, now to be established that the Eocene strata were formerly continuous, that the ele- vation of the Jurassic and Cretaceous mountain ranges is of more recent date, and that where the Eocene strata are absent this is due to denudation. The presence of fragments of Eocene, as for instance on the summit of the Ganterisch near Bovatez between the Jaun and the Fig. 83. — Section through the Mattstock. a S £ Montelon (though too small to be marked on the map), seems conclusive on this point. In many places the Secondary strata have been con- siderably reduced in thickness by the tremendous press- ure to which they were subjected during the process of folding. This is the case for instance on the north-\yest of the Mattstock in the Sentis where (Fig. 83) thq Urgonian (17") is reduced from its normal thickness of 220 metres to 30 metres, or to ^, the Gault from 70 metres to 10, and the Seewerkalk from 100 to 12, or 214 SCENERY OF SWITZERLAND chap. to ^. On the northern limb of the Gulmen Arch the Seewerkalk is reduced to j-^ of its original thickness, while elsewhere the strata form mere shreds or de- tached lens-like masses, and finally in some cases dis- appear altogether.^ Sentis Mountains and the Lake op Walenstadt The Sentis group and the Churfirsten occupy the tri- angle between the Lake of Walen and the Rhine. They are formed mainly of Cretaceous strata with a mantle of Tertiaries at their feet. The Sentis Mountains occupy the northern and wider part. They trend from N.E. to S.W. The N.E. end consists of six ridges, due to as many folds, the ridges being often Urgonian: they gradually coalesce a little north of Wesen into two, the Goggeyenberg (with the Hadernberg), and the Mattstock (Fig. 83), and finally to one in the Kiipfenstock. The ridges are generally anticlinal, but the highest summit is at the place where two synclinals meet one another. In the Churfirsten, which overlook the Lake of Walen, the strata (Fig. 26) are folded into a complete S. The configuration of the surface has been less affected by denudation in the Sentis than in most other Alpine districts.^ From the Sentis Mountains a glacier formerly streamed to the N.W., occupying the country between the Sitter and the Tlmr. The Walensee is a long valley originally due to a trough-like depression, the strata being actually folded back on themselves. The Strahlegg is a ridge of Urgonian. 1 Burokhardt, Bettr. z. Geol. K. d. Scliw., L. xxxii. 2 Heim, Mech. d. Geb., vol. ii. See however Rothpletz, Oeotek- tonische ProbUme, THE OUTER-ALPS 215 The Rigi The Rigi (Figs. 84, 85, and 88), as already mentioned, is the southern slope of a' great arch of Miocene Pud- /" Sattcrlipass Scheidego^°^^"'' Kigi Ttulm, ''^eehoden Ebonlem&nt diu Ito&Hherg Lac de Zug Fig. 84. — Section across the Rigi seen from tlie North, and sliowing the Rockfall of the Rossberg. dingstone, the summit and most of the north slope hav- ing disappeared. It is a gigantic bed of gravel brought from the mountains to the south. I — ; } Mollasse dkaU' datua feal%:l Glaciaire jr-^ ^1 r."'^:ij^^i i&Udsse Tnttrine- \Mallasso rouge ^^ Eocene j Urgonien^ ^^g^ Neocorniervw Fig. 85. — Section from the Rooterberg across the Rigi to the Vitznauerstock. The thickness of these gravel beds at the Rigi (some 5000 feet) is enormous, and they appear to have been folded back upon themselves, though the evidence is not 216 SCENERY OF SWITZERLAND chap. as yet conclusive. The mountain forms a long ridge. At the east end the MoUasse beds abut against Eocene and Cretaceous strata, which form the Hohfluh. The Rossberg is a continuation of the Rigi. From this mountain came the great rockfall of 1806 (chap. xxii). The railway passes over the rockfall, and enormous blocks may still be seen. It is indeed a wonderful geological lesson to stand on the summit of the Rigi and use the eyes and the brain. The view is magnificent. We see seven lakes, those of Lucerne, Zug, Lowerz, Egeri, Baldegger, Hall- wyl, and Sempach. To the north is the rich plain of Switzerland, and we can trace several rivers running nearly parallel with one another to the Aar ; to the west is the grand mass of Pilatus, of great geological interest, and fascinating from its mediaeval traditions ; to the east the Rossberg, still showing the scar of the great catas- trophe of 1806, and the two mysterious Mythen; to the south, range after range of mountains, culminating in the giants of the Bernese Oberlaud. Greatly as these latter appear to differ in height when we are near to them, as we look from such a point of vantage as the Rigi, we see that in reality the level is very uniform, the differences and the valleys being mainly due to denu- dation. Under our feet is a gigantic gravel bed stretch- ing completely down to the lake. Now, what are the lessons which this gravel teaches us? 1. It is obviously a gravel of mountain torrents, but which has come a considerable distance, for it is well rounded, and contains blocks up to 1 or even 2 feet in diameter. Well-rounded gravel implies transport for a consider- able distance. Bonney^ mentions that the gravel of the 1 Geol. Mag., 1888. xin THE OUTER-ALPS 217 Stura after a course of 32 km. was still subangular, and in the Sesia after 65 km. still only moderately rounded. 2. The character of the pebbles proves that it has come from the south. 3. This is also shown by the position of the pebbles, the flatter ones being arranged, as in modern streams, so as to offer most resistance to the current; and the position in this case shows that the stream came from the south. 4. The deposition of the gravel must have taken a prodigious time. Not only do the beds extend from the summit right down to the lake, but, as shown in Fig. 84, they slope from the Kulm to the Scheidegg. Those on the summit of the Kulm do not therefore correspond to those on the summit of the , Scheidegg, but so to say to those 500 feet below. It is obvious that the Schei- degg layers were once continued over the Kulm, and even if we assume that they represent the real upper- most layers (and it is certain that there must have been others which have been removed), we must add say 500 feet, to the present height of the Kulm. This being 4500 feet above the level of the lake, by adding these 500, we get a thickness of no less than 5000 feet of gravel ! 5. Gravel cannot be deposited on the top of a moun- tain. It must be formed by running water, either on a coast or in rivers; in the present case by rivers, and must therefore have been deposited at a relatively low level. As the rivers originally ran from the moun- tains to the S.E., the slope of the gravel must have been towards the N.W., whereas it is now towards the S.E., so that the gravel beds must have been tilted so as to dip in a direction the reverse of their original slope. That they do so slope we see clearly both from the lake and as we ascend. If, moreover, we examine the cliffs 218 SCENERY OF SWITZERLAND chap. overlooking the plain we shall find that, as shown in the figure, the layers of gravel dip in towards the hill in the direction of the Scheidegg. They were in fact origi- nally continued so as to form a great arch, the summit of which was (Fig. 85) approximately over the Bay of Kiissnacht, and the north-west side immediately on the other side of the bay, where the strata are nearly horizontal, rising however almost immediately into an- other arch, which forms the Rooterberg. We must therefore allow for another long period, during which the summit and north-west limit of the arch were destroyed and removed. 6. The actual pebbles themselves have been carefully studied by Dr. Friih, whose Memoir has been referred to in the previous chanter, and I will here only refer briefly to three points. 1. If the central mountain ranges had been as they now are, much of the gravel must have been derived from the Jurassic and Crystalline rocks ; but these are comparatively scarce, no doubt because at the time the gravel was being carried down the central rocks, now exposed, were covered by thick beds of the younger Secondary strata which have now disappeared. 2. Some of the pebbles are fragments of rocks, now only found on the Italian side of the central ridge. They cannot of course have been brought over such a ridge, and they prove therefore that the watershed was once considerably to the south of its present line. We shall find other evidence in corroboration of this inter- esting fact. 3. Others of the pebbles differ from any rock now found in situ. It has been suggested that this is because since their removal the parent rocks have been so com- pressed and contorted that their character and structure have been materially altered. THE OUTER-ALPS 219 Cretaceous Fia. 86. — Diagram showing North shore of Alps in Miocene Times. The features presented along the line of contact, between the Miocene and Eocene, present much diffi-. culty, and have given rise to various hypotheses. The strata are gen- erally conform- able, but this is by no means al- ways the case; for instance the Miocene strata of the Rigi abut against the steeply inclined Eocene and Cre- taceous beds of the Vitznauerstock (Fig. 85). These cases have been accounted for by supposing certain districts to have sunk, and great overthrusts to have taken place. Burckhardt explains the general concordance and occasional cases of discordance, by supposing that in the latter the Miocene strata were deposited in deltas. For instance. Fig. 86 is a diagram rep- resenting a deposit of Miocene strata in a delta. Now suppose a fold to take place, we should have the arrange- ment shown in Fig 87. If then subsequently de- nudation took place to the dark line X, the comparatively soft Eocene strata suffering most, we should have a section not unlike that of the Rigi and the Vitznauerstock. Fig. 87.— After Elevation of Alps. 220 SCENEKY OF SWITZERLAND chap. Mount Pilatus Mount Pilatus consists of Urgonian, Neocomian, Cre- taceous, and Eocene strata strongly folded. The ridges are mainly formed of Urgonian. Kaufmann^ describes five successive folds at the north extremity, which is the summit. Towards the south-west these folds are reduced to three. It well deserves its ancient name of Mons fractus — the broken mountain. From Staad, at the extremity of the Lake of Alpnach, the railway rises with a very steep gradient on the south- , , Rigilioclifliih /' \ Fig. 88. — Section of the Rigi and Eigiliochflue. east flank of the mountain. It crosses obliquely first the Eocene, then Urgonian, as far as the torrent of Wolfurt, where it crosses the first Neocomian anticlinal. It then enters the Eocene synclinal of Matt, touches the calca- reous summit of Esel, and terminates on the precipitous slope of Urgonian. The two hotels (Bellevue and Pilatus Kulm) are "sit- uated at the extremity of the Eocene synclinal, en- sconced between the two banks of Urgonian which form the principal summits of the mountain — the Esel and Oberhaupt. Behind the hotels, a zigzag path crosses the ridge of ' Beit. a. Geol. K. d. 8chw., L. v. THE OUTER-ALPS 221 Urgonian by the Kriesilocli, and traversing the folded Neocomian strata descends to the Klimseu Hotel, which Fig. 89. — Section througli Mount Pilatus. is situated in another Eocene synclinal. The two prin- cipal ridges of the mountain, those of the Tomlishorn and Matthorn, are formed of Schrattenkalk (Urgo- OherJiaupt Fig. 90. — Section of tlie Synclinal on the Pilatus near the Hotel Bellevue, nian), while the valley which separates them is an Eocene synclinal — a continuation of that in which the Hotel Bellevue stands. Glaenisch Double Fold In some cases the strata have been pushed for con- siderable distances one over the other — a fact which 222 SCENERY OF SWITZERLAND might seem incredible, but of which we have well- established instances in the Scotch highlands and else- where. One of the most wonderful cases occurs in the moun- tains between the Lin th thai and the llhine. The strata have been compressed in a great double fold, as is shown in Fig. 91. This double fold seemed so incredible that Studer, by Avhom it was first observed, hesitated to publish it. CuImGD leistkaiam "Waluuscs Soxsmor "^eissmeilsil Mageren ! Spitzmeilen, " I'lG. ill. — Sectiou from the Walensee to the Rhine at Fliins. 21, Mioceue ; S, Eocene; C, Cretaceous; J, Jurassic; I), Dogger; B, Rauchwacke; V, Verrucano. The subsequent researches of Heim seem, however, to place it beyond a doubt. Fig. 91 is a section from the Walensee, showing the remarkable folds of the Chur- firsten, to the Rhine valley at Waldhaus Flims. The manner in which the double fold dies away towards the east has not yet been clearly explained. The Glarnisch and the Silbern also present a stu- pendous example of inversion, the strata being folded XIII THE OUTER-ALPS 223 back upon themselves, so that we have Nummulitic limestone at the base, followed by Jurassic and Cre- taceous strata. I ought however to say that Rothpletz^ has pro- pounded another explanation, based on faults and overthrusts, which however also involves tremendous changes. Klippen I have reserved to the last the consideration of cer- tain mountains, for instance the Mythen, Stanzerhorn, Buochserhorn, and others, known as " Klippen," which present problems of great difficulty. It has been already mentioned (ante, p. 217) that the Nagelflue gravels consist in part of pebbles of un- known origin. The blocks of granite known as Habkern Granite, because they exist by thousands in the Habkern val- ley on the Lake of Thun, belong to a variety which does not occur anywhere in the Alps. Prof. Heim suggests that they perhaps represent some of the Alpine Granite before it was crushed and folded during the elevation of the Alps. The blocks are sometimes of great size ; the Berglit- tenstein on the Grabserberg for instance has a length of 40 feet.^ Another is 105 feet long by 90 broad and 45 feet above ground.^ In some cases they attain the dimensions of small hills, so that we have in fact every gradation of size from a mere pebble to such a moun- tain as the Stanzerhorn. Fig. 92 represents a section of the Roggenstock, and it will be seen that the more ancient Triassic and 1 Geotektonische Probleme. 2Quereau, Beitr. z. Geol. K. d. SeJiw., L. xxxiii. 8 Murchison, " Structure of the Alps," Q. J. Geol. Soc, 1848. 224 SCENEEY OF SWITZERLAND Jurassic rocks rest on the more recent Eocene beds, below which again are Cretaceous strata in regular arrangement, and with regular normal folds. The strata in the " Klippen " slope in the most differ- ent directions ; they are sometimes in the normal order ; sometimes, as for instance in the case of the Roggen- stock, reversed, the younger ones overlying the older ; the different kinds of rocks are mixed together in the utmost confusion : they are fractured, crushed, contorted in the most extraordinary manner, penetrated by veins, crossed by innumerable surfaces of sliding, and in fact fiAtemieA E11D94 OS) Ot 1 E 1 Cw "■/.■y.-/.:- o c< ?-v=»: ^^ C> Jtft "i^SIl Cw, Wangschic7it6n ; Cs, Chalk; H, Hawptdolomite ; J, Jurassic; K, Raihl&r Mergel. Fig. 92. — Section through part of the Roggenstock. have evidently been subjected to the most extreme vio- lence, while the Cretaceous and Eocene rocks below lie comparatively undisturbed. The "Klippen" form most conspicuous features in the landscape. To use Kaufmann's graphic expression they are " eckig, hockerig, rissig, und rauh," and rise in abrupt pyramids with steep, sharp points in striking contrast with the rounded grassy slopes of the Eocene and Cretaceous layers by which they are surrounded and on which they rest. Four theories have been suggested to account for XIII THE OUTER-ALPS 225 these remarkable mountains. First, that they were pushed up by subterranean forces through the more recent beds ; second, that they were islands in the sea, and that the more recent beds were deposited round them ; thirdly, that they are part of an inclined fold, of which the upper part has been removed by denuda- tion ; and fourthly, that they are the remnants of great overthrusts. It seems clear that the first supposition is untenable. The "Klippen" have no "roots." They rest upon the more recent strata. The Schien group to the N.E. of Schwyz'is cut to the base by a stream, so that it takes the form of a U, and the result is to expose the Flysch, and show that the other rocks actually rest upon it.^ Moreover, the more recent strata show little evidence of disturbances ; they present no traces of the fracture and crumpling which they must have undergone if the " Klippen " had been forced up through them. The second suggestion, namely, that they were Islands in the Eocene and Cretaceous seas, is also untenable. The Eocene and Cretaceous strata surrounding the "Klip- pen " were evidently deposited at a distance from land. They do not contain the remains of a littoral fauna ; and if the "Klippen" had stood up in the form of lofty islands, many pebbles from them must have been deposited in the surrounding waters. Nor do the " Klippen" appear to be the mere remnants of an overlying fold. It would be somewhat difficult to condense the strong geological evidence brought forward by Quereau against this theory. I may however mention one reason, namely, that the rocks of the "Klippen" present a very different facies from those of the same age in the immediate neighbourhood ; for instance the 1 Quereau, Beitr. z. Q-eol. K. d. Schw., L. xxxiii. Q 226 SCENERY OF SWITZERLAND chap. Neocomian of the Roggenstock differs greatly from the Neocomian of the surrounding district. The basis of the " Klippen," moreover, where they rest upon the Eocene, is a breccia, indicating that the upper strata have been pushed bodily over the lower. We find ourselves then driven to the conclusion that these mountains have been literally pushed into their present position ; that they are the last remnants of a range which has disappeared, and which perhaps sup- plied many of the enigmatic pebbles of the Nagelflue. The range was once continuous or nearly so; the frag- ments remaining, though now towering over the sur- rounding plains, owe their preservation to having been originally in a deep trough. The " Klippen " attain still greater importance to the west, where they form the mountain groxips of the Stockhorn and the Chablais. Haug^ and Lugeon have suggested that they have been forced to their positions from the Briangonnais, before the elevation of the intervening mountains : that the whole of the Pre-Alps from the Arve to the Lake of Thun in fact is a vast zone of overthrusts from the other side of the range of Mont Blanc. No doubt the strata present very much the same as- pect as those of the Briangonnais, and were evidently continuous ; but while the existence of an overthrust seems to be demonstrated, further evidence is still re- quired as to the locality from which they were brought. Other great cases of overthrust extending for several miles have, as Quereau points out, been established in Scotland, in Provence, in the Appalachians, and as we have already seen, by Heim in Glarus. Moreover, however improbable, not to say impossi- ble, this explanation may at first sight appear, we must 1 Haug, V Origins des Pre-Alpes Uomandes. Xlli THE OUTER-ALPS 227 remember the enormous disturbances of which we have the clearest proof. As already mentioned it has been calculated that the strata which lie between Basle and Milan, a distance of 130 miles, would, when extended, have occupied 200 miles. The origin of the " Klippen " is still, however, a mat- ter of discussion, and in the most recent memoir on the subject, M. Ch. Sarasin^ and M. Schardt^ differ in sev- eral respects from the conclusions of M. Quereau. 1 Arch, de Geneve, 1894. 2 Schardt, " Struct. G6ol. des Pre-Alpes," Bib. Univ., Geneve, 1892. CHAPTER XIV CENTRAL MASSrVES The Alps are not, strictly speaking, a chain of mountains, but rather a series of bosses, or "central massives," to use the term of the Swiss geologists. Speaking generally, we may say that the Central Massives have Gneiss as the central rock with Crystal- line schists, of uncertain age, on the sides ; followed by other rocks undoubtedly of sedimentary origin, but so much metamorphosed that it is in many cases difficult, or even as yet impossible, to determine their geological position. The Central Massives were at first regarded as grand but simple arches, and this impression is still widely dif- fused, partly because in the small generalised sections which alone can be given in text-books, it is impossible to give details. Their structure is much more complex than would be inferred even from the largest geological maps. In Studer's excellent map, for instance, the whole of the St. Gotthard route from Erstfeld to Lugano is coloured as Gneiss, with the exception of three belts — that of Protogine from Wasen to Goschenen ; of the Second- ary strata which constitute the Urserenthal, and another secondary belt forming the Bedrettothal, and crossing the Ticino at Airolo to the Val Piora. The great Swiss Dufour map shows that the structure is far from being so simple ; but in fact no map can adequately 228 CHAP. XIV CENTRAL MASSIVBS 229 show its real complexity. The following figure (Fig. 93) gives a faint idea of the complexity of the St. Gotthard Massif. The whole tendency of recent re- searches has been to demonstrate that the structure of these "central massives" is much more complicated than had been at first supposed — to confirm Saussure's wise saying that " Es giebt in den Alpen nichts Con- stantes als die Mannigfaltigkeit." In this respect, however, the massives differ consider- ably. Monte Rosa, for instance, is simpler than the St. Gotthard. Indeed, the southern Gneisses are, as a general rule, much lest contorted than those in the northern massives. The strata form more or less lenticular masses, and are very varied in composition and structure — the Gneiss itself presenting many varieties. The Gneiss, Granite, Protogine, and even apparently Mica Schist pass almost imperceptibly into one another. " The changes of texture and condition," says Escher, " vary not only in different layers, but even in different parts of the same layer, so that we often pass from one extreme to the other by imperceptible gradations." Grubenmann,! who has recently published a special memoir on the Granites of the St. Gotthard, suggests that they may all have been derived from an originally similar rock, modified by differences of pressure and temperature. Schmidt suggests that we find normal Granites in just those parts of the central massives where we should expect the pressure to be less extreme, while Protogine occurs in the more intensely folded parts. Heim has pointed out that many rocks which in hand specimens might well be taken for Granite are shown 1 Verh. Thurgaisch. Nat. Ges., 1890. 230 SCENERY OP SWITZERLAND chap. to be really stratified if seen in larger masses. As already mentioned he regards some varieties of Gneiss as part of the original Earth's crust. He regards parts of the Protogine as compressed Granite, and some of the Gneiss as compressed Protogine ; while other Gneiss masses he regards as metamorphosed sedimentary rocks, and he refers to places where the one passes impercep- tibly into the other. Duparc and Mrazec,^ who have especially studied the Protogine of the Mont Blanc Massif, regard it as a granulitic Granite, "presentant une disposition en bancs plus ou moins epais, acquise a la suite d'actions dyna- miques ulterieures a sa consolidation." On a larger scale the sections show repeated succes- sions of similar rocks, and the more they are examined the more complicated do they appear. In the Aar profile we find Granite repeated at least nine times, Gneiss-Granite ten times. Eyed-gneiss, Mica Gneiss, and Gray Gneiss several times. In the Reuss Valley the Granite and Crystalline schists alternate some twenty times in a distance of 4 km. The Urseren fold is itself double. These changes may in some cases be due to faults and overthrusts, but in general appear to indicate folds. Baltzer considers that the Aar mas- sif comprises at least six.^ The following figure (Fig. 93) representing the sec- tion of the St. Gotthard Tunnel, shows this complexity very clearly. The existence of "bosses," such as the great "mas- sives," would naturally follow from the general view of the Swiss Alps, which has been given above. It would be most improbable in any case, that we should have a simple succession of ridges extending the whole length ''■Arch. Sc. Fhys. et Nat. de Geneve, 1892. - Baltzer, Beitr. z. Geol. K. d. Sckw., L. xxiv. CENTRAL MASSIVES 231 of the mountains, and especially so in a curved chain, such as the Alps. Moreover, we find as a matter of fact, that folds rarely extend the whole length of a range. In the Jura, for instance, which extends over 300 km., the folds have lengths of 12, 27, 28, 31, 45, 14, 51, 92, 48, and in one case 162 km. respec- tively. The length, I may add, has no rela- tion to the height. Thur- mann calculated that for the whole Jura there are no less than 160 folds, though there are never more than 12 in any one cross section. As a rule the strata on the northern line of the Central Massives are in- clined at a high angle, and indeed are in places perpendicular. This may be said to be the rule in the centre, while they are less steeply in- clined at the sides. The inclination, however, in- stead of being, as might at first sight have been 2 m cS CO "S r^ rs 232 SCENERY OP SWITZEELAND expected, away from the centre, trend towards it. Indeed, so extreme has been the pressure that the central ranges have been squeezed into a fan-shaped structure, long ago noticed by Saussure, well described by Studer, but fii"st explained by Lory. Fig. 25 gives a section across the Mont Blanc range. A similar fan-shaped structure occurs in the St. Gotthard (Fig. 26), the Grimsel, the Silvretta, etc., and may indeed be said to occur in all the northern Crystalline Massives of the Alps, but not in the Ticino, Fig. 9i. Fig. 95. Diagrams showing the Structure o£ Folded Mountains. Adula, etc. It has also been found in the Pyrenees, in Pennsylvania, and some other mountain ranges.^ Figs. 94 and 95, showing the folds assumed by layers of clay, sand, etc., in two of Mr. Cadell's experiments, compared with the section of the Mont Blanc Massif given in Fig. 25, or that of the St. Gotthard in Fig. 26, show how the structure of these mountain ranges may have originated. In attempting to understand the structure of the Central Massives, the first problem which confronts us is the true nature of the Crystalline rocks. They were long regarded as intrusive plutonic rocks, which had forced up, and were therefore younger than the Second- ary strata. As already mentioned, however (ante, p. 25), they are now regarded as essentially passive, not iFavre, Bech. Geol., iii. XIT CENTRAL MASSIVES 233 active ; not as having forced up the Secondary rocks, but as having been forced up with them by the same lateral pressure ; as being of extreme antiquity, and indeed in the opinion of some geologists as part of the original crust of the Earth. Some Swiss geologists consider that the Crystalline rocks had been not only denuded, but also much folded before the deposition of the Secondary strata ; other great authorities, as for instance Heim, dispute this ; they consider that the earlier folding was comparatively slight, and that in the main the folding of the Gneiss and the Secondary strata was simultaneous. The Central Massives, the Mont Blanc Massif, the St. Bernhard, Monte Rosa, Aar, St. Gotthard, Adula, etc., are at present more or less completely detached. It has long been a question whether these mountain masses should be regarded as independent centres of elevation or as parts of a general system. As long as mountain chains were regarded as having been thrust up from below by volcanic action, the former view seemed most probable. The structure of the rocks affords no conclusive evi- dence. They agr.ee no doubt in general character. The Gneiss of the Aar Massif cannot be distinguished from that of the St. Gotthard Hospice. The Protogine also repeats itself. That of the St. Gotthard Massif from Medels to Somvix is practically identical with that of Mont Blanc. On the other hand the fundamental rocks are very similar all over the world. Moreover, underlying this similarity there are considerable differences in detail. These differences may be in many cases due to me- chanical causes — those, for instance, between the St. Gotthard and the Adula, perhaps to the fact of the former being more compressed. It seems clear, how- 234 SCENERY OP SWITZERLAND chap. ever, that the rocks in each differ as much as those be- tween different "massives." Moreover, as the rocks included in the folds between the massives are of the same age, we can hardly doubt that this applies to the massives themselves. Here also the analogy of the Jura is very instructive. The bosses there are not on so grand a scale, they are not formed of such ancient rocks, and they are not so far denuded; but they are clearly parts of a system, and I cannot doubt that the same is the case with the great massives of the central Swiss chain. The Granite is no doubt for the most part of great antiquity, pebbles of it occurring in Carboniferous Puddingstone ; it crops .up in many places, now more or less detached, and there were probably several dis- tinct eruptions of this rock ; but the action of subse- quent denudation has divided many tracts which un- questionably were once continuous. Some Granite is no doubt intrusive. This is shown by the fact that the rocks near it are in many places forced up and modified by heat. Still it would be a mistake to regard the Granite as having been the active agent of disturb- ance ; it was, on the contrary, itself forced up by the general side pressure. In some cases it appears not to have entirely broken through the overlying rocks, but is exposed in deep ravines. ^ I have already shown that the central massives were once covered by a great thickness of Secondary rocks. Apart from this evidence, however, we must bear in mind that Gneiss, Granite, and Crystalline Schists must have cooled under great pressure and at a great depth. When we stand on such a rock we must in imagination replace over it several thousand feet of I Theobald, Beitr. z. Qeol. K. d. Schw., L. iii. XIV CENTEAL MASSIVES 235 rock now removed. Gneiss would as it approached the surface gradually have assumed a totally different character, the superficial parts probably not differing greatly from modern lavas. These upper layers were removed by denudation, and on the surface thus exposed was deposited a great thick- ness of Sedimentary rock. Figs. 25 and 26 show that on both sides of the Mont Blanc Massif and that of the St. Gotthard are folds of Secondary strata ; these must have been originally continuous, and have passed over the intervening mountains in a great arch. Sorby, as already mentioned, considered that the Granites examined by him had cooled at a depth of no less than 30,000 feet. While, then, we have still much to learn as to the structure of these central massives and their relation to one another, there are strong, not to say conclusive, reasons for regarding them, (1) As an integral part of the general Alpine sys- tem, not as independent centres of upheaval, and (2) as complex systems of compressed folds. CHAPTER XV THE LAKE OF GENEVA Mon Lac est le Premier. — Voltaire The Lake of Geneva is 45 miles in length, and atout 10 in breadth. It is 375 metres above the Sea, and 309 in depth. The bottom, moreover, is covered by subsequent deposits to an unknown depth, so that originally it was probably below, perhaps much below, the Sea-level. Indeed, if the slopes of the mountains at jVIeillerie and Vevey (see Fig. 100) are continued under the bed of the lake, the alluvium must have a thickness of no less than 600-800 metres, which would make it 200-400 metres below the Sea-level. The actual outlet at Gen- eva is in superficial debris, but the river comes upon solid rock at Vernier, 1197 feet above the Sea-level, 33 feet therefore below the surface level of the lake, and 951 feet above the bottom. It is therefore a true rock basin. In the Port of Geneva, a little to the S.E. of the Jardin Anglais, are tAVO erratic blocks Avhich project above the water. They are known as the Pierres de Niton, and it is said that in Roman times sacrifices were offered to Neptune upon them. The Lake of Geneva has somewhat the form of a crescent, and if we remember that the valley, as far at any rate as St. ]Maurice, if not to Brieg, was once part 236 CHAP. XT THE LAKE OF GENEVA 237 of the lake, the resemblance must have been even more marked formerly. Port Valais is supposed to have been on the lake in Roman times. The primary rocks nowhere make their appearance round the Lake of Geneva. The east end of the lake is a transverse valley cut through a succession of syn- clinal and anticlinal folds in strata extending from the Triassic to the Tertiary. The rest of the lake from Clarens on the north, and Meillerie on the south, lies in Miocene (Mollasse), which, however, is in many places covered by glacial deposits. On the south especially, these attain a considerable thickness. Most of the promontories round the lake are trav- ersed by a stream ; they are, in fact, river cones. That of Yvoire, however, cannot be so accounted for ; and Favre ^ has pointed out that it is, in fact, a great moraine. It is one of the most picturesque districts of the whole shore. The view of the lake, the magnifi- cent groups of chestnuts, and the innumerable erratic blocks give it quite a special character. The plain on the south side of the lake, and even the high terrace of St. Paul, above Evian, is entirely erratic, and due to the confluence of the ancient glaciers of the Rhone and the Drance. "V ^cftjs5^^V Vevfyse ^__^ SB The deposits at- tain an immense thickness in the ' ■^ Fig. 96. — Section across the Valley ol the Veveyse. Drance above Thonon, from the study of which Morlot many years ago convinced himself of the existence of at least two glacial periods. The chain of the Voirons is an anti-clinal N.S. ridge, 1 HecU. Geoh, vol. i. I %*g I River Cones \■:■:■:;;;r^ Rock-falh ^^'y,''.z'J{i:"'-{J''J crrafi'c dehosits \Mid.&'Low.Lia.s ^(f&^ rhatisck ^I^Gyjinim Fig. 97. — The East End of tlie Lake of Geneva, and Part of the Khone ^'alley. 238 CHAP. XV THE LAKE OP GENEVA 239 overthrown to the west ; and the arch is more or less profoundly broken to the Flysch, the Neocomian, or even the Malm.^ The country about Vevey and Montreux is the Ri- viera of Switzerland. It is lovely now, but what must it have been before the monotonous terraces of the vineyards, and the endless rows of vine bushes replaced the ancient forests of Chestnut, Birch, and Beech; and the picturesque Swiss chalets were extinguished by whitewashed villas and gigantic hotels. ]\Iorlot first called attention to the existence of a fault to the west of Vevey. It begins at Gonelles, Fig. 98. —Transverse Profile of the Valley of the Tiuifere, near Villeneuve. just to the west of the town, and goes in the direction of Chatel St. Denis, following for some distance the right bank of the Veveyse. The cone of the Tiniere is particularly interesting from the attempt made by M. Morlot to calculate roughly the date of the later Stone age in Switzerland. He estimated for the age of Bronze an antiquity of from 2900 years to 4200 years, for that of the Stone period from 4700 to 7000 years, for the whole cone of from 7400 to 11,000 years. 1 Renevier, Add. Pres. Soc. Helv. des Sc. Nat. 1893. 240 SCENERY OP SWITZERLAND At the eastern end of the Lake of Geneva (Fig. 97) the strata are thrown into a series of arches on the north side. Messrs. Renevier and GoUiez give the fol- lowing series : — 1. Anticlinal valley of the Verage at Jaman. 2. Synclinal ridge of Sonchaud at Naye. 3. Anticlinal valley of the Tiniere (Fig. 98). 4. Synclinal valley of the Eau Froide (Cretaceous and Flysch). 5. Anticlinal Cirque of Corbeyrier (Triassic). 6. Synclinal plateau of Leysin. 7. Anticlinal valley of the Grande Eau, excavated down the Trias. The Tour d'Ai which forms so conspicuous a feature in the landscape at the eastern end of the liake of Gen- eva is, as shown in Fig. 99, the point of a broken arch of ]Malm. ■-__ Tour d'Ai Fig. 99. — Section across the Tour d'Ai. From the Rocher de Naye, now ac- cessible by a moun- s.E, tain railway, there is a glorious view. To the east the Bernese Oberland, further west the Dent du Midi and the extreme summit of Mont Blanc, to the north the great plain of Switzerland, around us the Pleiades, etc., the Tours d'Ai and de Mayen; a Avilderness of ridges and valleys, gray precipices, steep bright green grass slopes, mottled with dark masses, patches, lines, and groups of pines, below which are paler green deciduous trees, and at our feet the blue water of the Lake of Geneva. THE LAKE OF GENEVA 241 Conformation op the Lake Though the form of the lake is in itself so simple, the lake is in reality formed of two converging basins : that of the east which is a cross valley, while the west- ern half, like the Lakes of Neuchatel, of Bienne, and of Morat, follows the direction of the Jurassic chains and the anticlinal axis of the Mollasse. The Petit Lac, the Lake of Neuchatel, and that of Bienne may almost be said to form one lake basin. It probably originated at the same time as the mountains, which have the same general curve as that part of the lake.^ The eastern end on the contrary as far as a line crossing from Vevey to Meillerie is a transverse valley or cluse, cut through the Secondary and Eocene strata, which are thrown into a succession of synclinal and anticlinal folds. The greater part of the original " Haut Lac " is now a plain, filled up to an unknown depth by the deposits of the Rhone. The " Haut Lac " is in fact a transverse river valley cut out by the Rhone, and subsequently, owing to a change of inclination, partly filled up again. This distinction between different parts of the lake is to some extent recognised in the local nomenclature, the eastern end being known as the "Haut Lac," the centre as the " Grand Lac," and the narrower western end as the "Petit Lac." The water of the Rhone from its greater density sinks rapidly below the blue water of the lake, but the fine mud is carried half-way across the lake, and covers the bottom as far as Amphion and St. Sulpice. The " Grand Lac " is bounded on the north by Mio- cene Mollasse, on the south as far as Tour-Ronde by 1 Favre, Rech. Geol. , vol. i. 242 SCENERY OP SWITZERLAND Scale: iorizoital li200 000«, vertical 1:25 000=. Fig. 100. — Profile across the Lake of Geneva from Cully to Meillerie. Lias and Jurassic, and further to the west by immense alluvial and glacial deposits. The centre (Fig. 100) is occupied by an almost horizontal plain at a depth of 309 metres, in- dicating that the allu- vium must be of great depth. The western half of the lake is in almost horizontal middle strata of middle Miocene MoUasse. It was therefore excavated after the middle Miocene, and before the close of the Glacial epoch. As already mentioned, there is some reason for sup- posing that the Petit Lac was originally the valley of the Arve. It presents a general inclination from Gen- eva to INIorges, but with some slightly marked basins, owing to transverse banks, which Forel considers to be ancient moraines. The sides, moreover, like those of an ordinary river valley, slope more or less towards the centre. I have already (ante, p. 148) given reasons for thinking that the outflow of the waters was formerly, not at Geneva, but between Morges and Lausanne, to the Lake of Neuchatel. The following figure gives the profile from St. Prex to Amphion. It must always be remembered that the vertical and s^p Scale: horizontal 1:200 OOO". vertical 1:25 000«. Fig. 101. — Profile across the Lake of Geneva from St. Prex to Amphion. horizontal scales in this and other similar figures are quite different. They bring out clearly the special XV THE LAKE OF GENEVA ' 243 point which they are intended to illustrate, but in other respects might give an erroneous impression. We generally think of the Lake of Geneva as deep, but taken in relation to its area it might almost be described as a film of water (see Fig. 68). Between Yvoire and Rolle and at a depth of 60 metres, is a remarkable bank known as the Ombliere, because it is the best fishing ground for the "Omble Chevalier," which comes there to breed. It is an old moraine, and is also remarkable because a moss (Thamnium alope- curum, var. Lemani) still lives on these stones.^ The " blue waters of the arrowy Rhone " ^ " rush out with a depth of 15 feet," says Ruskin, " of not flowing but flying water ; not water neither, melted glacier matter one should call it ; the force of the ice is in it, and the wreathing of the clouds, the gladness of the sky, and the countenance of the time." ^ Tlie remains of the lake villages show that, as in the other great lakes, the surface level has varied very little for several thousand years ; for if the water level had been lower, the remains would have been destroyed, and on the other hand the piles could not have been fixed in deeper water. At present the lake is maintained at a nearly constant level by dams and sluices at Geneva. The condition and configuration of the Lake of Gen- eva oft'er many difficult problems, as to which there is still much difference of opinion. The course of the Rhone below the Lake of Geneva is extremely curious and interesting. It presents many indications of comparatively recent origin, or at any rate of recent changes.* At the Fort de I'Ecluse it 1 Forel, ie ieroare. ^ Byron. ^ Euskin. * " Le Canon du Rhone," Bull. /Soc Geol., France, 1894 ; Sohardt, "Cliaine de Keoulet Vuaohe," Eclog. Geol. Selv., 1891. 244 SCENERY OF SWITZERLAND passes through a narrow canon or gorge, several hun- dred feet in depth, between the Credo (Cret d'Eau) and the Vuache Mountain (Fig. 77). The gorge coin- cides witli a cliange in tlie direction of the mountain chain whicli has, according to Bourdon, given rise to a fault, the difference of level between the Credo and the Vuache amounting to 1000 metres. It then enters a plain, and at Bellegarde joins the Valserine, which, though the smaller, is really the mother river. Imme- diately above the junction is the celebrated Perte du Rhone, where the river narrows to about 15 metres,^ Fig. 102. — Longitudinal Section of tlie Perte du Rhone. and when it is low disappears more or less completely for 20 km. running in a deep, narrow, winding, and often invisible bed. This is due to the presence of horizontal layers, differ- ing considerably in hardness. Fig. 102 represents a longitudinal, and Fig. 103 a transverse, section — a, « are hard Calcareous strata, b, b softer layers. The boulders with which the river is laden, by degrees broke through the harder rock in various places, and then be- gan to act more effectively on the softer stratum below, which they gradually ate into more and more, finally meeting, and thus forming a sort of tunnel sufficient ' LenthSrlo, Le Bhone, vol. i. XV THE LAKE OP GENEVA 245 to carry all the water of the river when it is low. The lower Calcareous layer has in some places been itself worn through, so that the same process is beginning a second time. Neither the Rhone nor the Arve would by itself have been able to effect this. It requires gravel and bouldeVs, animated by a sufficient force of water. The Rhone is large enough, but does not carry down enough stones. The Arve has plenty of gravel and stones, but not enough flow of water. Thus the Rhone supplies the force and the Arve the tools. Fig. 103. — Transverse Section of the Perte du Rhone. From the Fort de I'Ecluse to below Malpertuis the Rhone is not a river, but a torrent. It has not had time to approach its "regimen." Below Bellegarde the slope of the river is the reverse of that of the valley. The river slopes from Bellegarde to Malpertuis, the valley from Malpertuis to Bellegarde. The river falls 20 to 25 metres, the ground rises over 200. At Bellegarde the gorge has a depth of 200 metres, at Malpertuis of 450. Thus while the river falls the valley rises. ■ If this had always been so it is evident that the Valserine and the Rhone would have formed a deep lake, the bottom of which they would have filled with river deposits, and round which we should find traces of lake terraces. Of such a lake, however, there is not a trace. Near Malpertuis the inclination of the ground changes, 246 SCENERY OF SWITZERLAND chap, xv slowly at first, afterwards more rapidly. The slope of the valley coincides with that of the stream, and at Seyssel the Rhone is a river again. The relation of the drainage to the surface is therefore very remarkable. We are driven then irresistibly to the conclusion that the high ridge between the Perte and Seyssel is of comparatively recent origin ; that it has risen since the Rhone ran in its present channel, and that it was cut through by the river as it rose. M. Bourdon is disposed to think that it is actually still rising. He points out that the present heights in many cases differ from those marked on the Govern- ment map, but it is very possible that they may have been right when the measurements were made, and have since altered. There has been a law-suit going on for nearly two centuries between the Canton of Vaud and that of Geneva, the former alleging that the mills, dams, etc., at Geneva have raised the level of the lake, flooding some of their roads and fields. The evidence they have produced seems conclusively- to show a slight elevation of the level of the water. On the other hand the peo- ple of Geneva appear to have proved that there has been no such change of level there. It seems possible that both may be right and that Geneva is even now slowly rising. Time will solve this interesting problem. On the whole it seems probable that the two ends of the Lake of Geneva represent the river valleys of the Rhone and the Arve respectively ; that they met the Dranse opposite jMorges, and that the combined river ran north to the Lake of Neuchatel ; that an elevation of the land then dammed back the water, giving rise to the lake ; and lastly, that the cutting of the gorge at Fort de I'Ecluse gave the lake its present exit to the west, and gradually lowered the level. CHAPTER XVI THE MASSIF OF MONT BLANC II y a dans la nature oomme dans les arts des choses diffioiles i comprendre, qu'on doit voir ou entendre plusienrs fois pour en saisir la grandeur; il en est ainsi de la oliaine du Mont Blanc, plus on la voit et la parcourt, mieux on en saisit la beauts. Favee. The Massif of Mont Blanc is elliptical in outline, about 30 miles in length, and 10 in breadth, extending from S.W. to N.E. from the Col de Bonhomme, across the Valais at Martigny to the Dents de Morcles, the extreme N.E. portion being severed from the rest by the Rhone. It consists mainly of two unequal ranges (see Fig. 104), the lesser, that of the Aiguilles Rouges on the N.W., and the greater Mont Blanc range on the S.E., separated by the longitudinal valley of Chamouni, and bounded by two others, the Vallee de Sixt on the north, and the Val Ferret on the south. These valleys have been greatly deepened by erosion, but are clearly due in the first instance to geotectonic action. Thus the Val Ferret extends from the AUee Blanche on the west to Sembranchier on the east, but with higher portions at the AUee Blanche and the Col de Ferret, so that the waters meet one another almost half-way between the two at the foot of the Glacier de la Brenva, when they turn south through a transverse valley to Villeneuve, S.W. of Aosta between Mont Chetif and the Mer de la Saxe, which seem to guard the entrance, as Studer says, like the pillars at the entrance of an Indian temple. 247 248 SCENERY OF SWITZERLAND The central range and the summit of Mont Blanc itself (4810 me- tres) consists mainly of Protogine, flanked as we pass to the north by Crystalline Schists of undetermined age, suc- ceeded by strata belong- ing to the Carboniferous, Jurassic, and Cretaceous periods. The Grands Mulcts and the Dome du Goute consist of Crystalline Schist, which indeed sur- rounds the whole massif, except on the south side, where it is wanting in the Val Veni, the Val d'Entreves, and the Val Ferret. In this respect the north and south sides of the chain present a remarkable contrast. Figs. 94 and 95, adapted from ]Mr. Ca- dell's experiments on the foldings of com- pressed layers of clay, illustrate the structure of the Central Massives ; that on the right giving the "fan" structure, while that on the left XVI THE MASSIF OF MONT BLANC 249 shows an overthrust, and suggests a possible explana- tion for the absence of the Crystalline Schists on the south of the Mont Blanc range. Carboniferous strata occur on both sides of the Arve from Servoz almost to Les Ilouches, and extend east- wards in two bands — one from Servoz towards Mont Buet, the other from below Argentiere over the Col des Montets down the Trient to Vernayaz, and across the Rhone to the Mont de Fully. The broad valleys of Chables and of Liddes are also due to the compara- tive destructibility of the Anthracitic shales belonging to this period. The three principal representatives of the Carbonif- erous strata are (1) argillaceous schists, frequently containing vegetable remains ; (2) micaceous sand- stones, which often much resemble some of the Crys- talline Schists ; and (3) the remarkable conglomerate known as the Puddingstone of Valorsine. This Puddingstone consists of rolled pebbles and blocks, sometimes over a foot in diameter. These must have been brought doAvn by torrents much re- sembling the Alpine torrents of the present day, and indicate therefore the presence of former mountains. The pebbles consist principally of primitive rock, mainly Gneiss, but comprise no Granite or Porphyry, so that these rocks cannot then have been exposed, but must have been covered and protected by other strata. The pebbles are mixed with Quartz and Mica embedded in a hard reddish cement. Blocks of this Pudding- stone, as already mentioned, have been transported by the glacier to a great distance. It was well studied and described by De Saussure in 1776 at Ceblancs, on the north of the mountain Les Posettes, where the layers are vertical, while, as De Saussure remarked, they must have been horizontal, 250 SCENERY OP SWITZERLAND chap. or nearly so, when originally deposited. " II faut done regarder," he says, "comme une chose demon- tree, que ces poudinges ont ete formes dans une posi- tion horizontale, ou a pen pres telle, et redresses ensuite apres leur endurcissement." This important observation was the first proof of the elevation of Sedimentary strata. ^ However self-evident this may appear to us now, it seemed extraordinary at the time, and Bertrand even attempted to show that the pebble beds might have been, deposited in a vertical position! The proportion of pebbles in this deposit varies greatly. Sometimes they form nearly the whole, with only enough cement to hold them together. At other places they are comparatively few, or even alto- gether absent, in which case it is very difficult to dis- tinguish this rock from one of the Crystalline Schists. Favre indeed suggests that some of the rocks which have been regarded as Crystalline Schists in reality belong to the Carboniferous period. The Val Ferret and the valley of Chamouni are syn- clinals, and contain Jurassic strata. As regards Mont Blanc itself, " Je n'entreprendrai pas," he says, " de d^crire I'apparence du Mont Blanc, on ne pent se faire une juste id^e de cette chaine cou- verte de frimats ^ternels et orn^e de mille pointes de rochers, sans I'avoir visit^e. II y a dans la nature, comme dans les arts, des choses difficiles a comjjren- dre, qu'on doit voir ou entendre plusieurs fois pour en saisir la grandeur; il en est ainsi de la chaine du Mont Blanc, plus on la voit et la parcourt, mieux on en saisit la beauts." ^ The whole district is of singular beauty. "I have climbed much," says Ruskin, "and 1 Favre, Bech. Geol., vol. ii. - Eavre, Bech. Oeol., vol. ii. XVI THE MASSIF OF MONT BLANC 251 wandered much, in tlie heart of the high Alps, but I have never yet seen anything which equalled the view from the Montanvert." Favre also speaks of this district with great, though not too great, enthusiasm, as "des lieux enchant^s," and returned over and over again to the Pavilion de Bellevue during his geological studies. He does not know which to commend most, the splendid air or the magnificent views, which, as he justly says, surpass all description. The true continuation of the valley of Chamouni eastwards is not the Col des Montets and the T§te Noir, but the Col de Balme. The Arve descends in a longitudinal valley to Les Houches. Here the west- ern line of the valley passes over the Col de Voza.- The river, however, breaks away to the north in a transverse valley, cutting across the Carboniferous strata. The contrast of the narrow and wild transverse gorge, with the more open longitudinal valley above, is very marked. Below Servoz for a short distance the river again occu- pies a longitudinal valley, and then from Sallenches runs transversely by the narrow gorge at Gluses to Bonneville, where it emerges on a wide alluvial plain. As already mentioned, the Val Ferret on the south, and the mountains on the west, which stretch from the Rhone valley, south of St. Maurice, to the valley of the Arve at Servoz — the Mont Euan, the Cheval Blanc, and the Mont Buet, are Jurassic : and the question arises whether the Secondary strata once extended in a great arch over the Protogine of Mont Blanc. This can now be confidently answered in the affirmative, and the final proof is due to M. Favre. On a memorable occasion, 12th August, 1847, he ascended the Aiguille de Gli^re. It was a splendid day, and he says,^ " Je fis 1 Favre, Bech. Geol., vol. ii. 252 SCBNEKY OF SWITZERLAND chap. une longue station au sommet de cette aiguille, jouis- sant de divers points de vue. Je considerais longtemps avec un inexprimable plaisir cette scene majestueuse, inais tout a coup je remarquai, au Nord-Est, dans I'une des Aiguilles Rouges, une structure qui me ramena su- bitement a un autre ordre d'idees, non moins grand et non moins releve que la rSverie oil m'avait plong^ la contemplation du grand spectacle que j'avais sous les yeux. "Je voyait toutes les Aiguilles Rouges form^es de gneiss en couches verticales ; je les examinais avec la lunette, lorsque je fus frapp^ de I'espdce de chapeau que portait la plus elevee. Ce chapeau (Figs. 104, 105) est form^e par des couches presque horizontales, reposant sur les tranches du gneiss qui composent le corps de la montagne. Cette vue captive toute mou attention. II 6tait Evident que la discordance que je voyait entre les couches presque horizontales et le gneiss indiquait que le chapeau de 1' Aiguille Rouge ^tait d'une autre nature que I'aiguille meme." The " cap " was in fact formed of Jurassic strata, con- clusively demonstrating that the Secondary rocks once extended continuously over the massif; and to judge from their thickness elsewhere, the amount of the Sec- ondary rocks denuded can hardly be less than 3000 metres, to which a substantial addition must be made, as a considerable thickness of the crystalline rocks has also been removed. Whether the same can be said of the older Tertiary strata is not so clear, but as they terminate along the north side of the Mont Blanc massif in a great escarp- ment, it is certain that they must at any rate have ex- tended far beyond their present limits. South of the Alps the cretaceous and nummulitic strata reappear in the neighbourhood of Varese and Turin. THE MASSIF OF MONT BLANO 253 At any rate, however, the Secondary strata formed a great arch over the Buet, dipping down into a com- pressed synclinal fold, which was the determining cause of the valley of Chamouni, and then (Figs. 104, 105) rose up into a great arch over the central Mont Blanc range. Mont Blanc therefore was once covered by from 10,000 to 15,000 feet of strata, which have been entirely removed. The lapse of time thus indicated must have been enormous. It has been calculated that the general surface of the land is lowered by the action of rain I ^ fl ■k ii ■•-VL^^i;*^'^"'-"'-^"""'"''''" ""iSs^'"^ "l^f 1'" '^...j...ysi Fig. 105. — Section from Sixt to Chamouni. and rivers about one metre in 12,000 years,^ though no doubt the rate would be greater in mountainous regions. The valley of Chamouni presents grand evidence of glacier action. It contains numerous erratic blocks and several glaciers. That of Argenti^re almost closes the upper valley. It has a height of over 100 metres, and was the right lateral moraine of the Glacier d'Argentiere. The right lateral moraine of the Glacier des Bois does not stop with the glacier, but is prolonged in the form of an immense rampart, which formerly extended right across the valley, damming back the river, and forming ■ Penck, Morplwlorjie cler Erdoberflaclie, vol. ii. J3 o 2 CHAP. XVI THE MASSIF OF MONT BLANC 255 a lake. It has now, however, been cut through by the Arve, forming the Passage des Tines. It has a height of over 170 metres, and one of the largest of the blocks, known as the Pierre de Lisboli, is 15 metres in length. The Arve has raised the whole valley above this moraine. Chamouni itself is built on, and to a great extent of, a former terminal moraine of the Glacier des Bois. This is shown by the character of the blocks, which are of Granite, very different from the rocks of the Brevent. Lower down the valley, at Montquart, is another mo- raine^ which ends a little below the torrent coming from the Glacier de Taconnaz. One of the blocks belonging to it, known as the Pierre Belle, is 24 metres long, 9 wide, and 12 in height. At an earlier period, however, the whole valley was filled by the glacier, and all along the face of the Mont Blanc range the upper limit of the ice can be clearly traced (see Fig. 106). At this epoch the glacier di- vided, one branch passing down the Arve, the other over the Col de Balme, and the TSte Noir to the Valley of the Rhone. These moraines are very instructive, because they con- nect so clearly the ancient glaciers of the Ice age with those of the present day. In the valley of Chamouni glacial action, as indicated by the smooth and rounded surface of rock, can be traced over the Col des Montets between Valorsine and Argen- tidre, a height of 1474 metres, at the Chalet de Pliampra, 2080 metres, and to the summit of the Posettes, 2208 metres. At the bend of the river Arve, opposite Les Houches, where the river turns abruptly into a transverse valley, the rocks are greatly glaciated. At Chatelard, near Ser- voz, at the right side of the road, are several very fine Giants' Caldrons. 256 SCENERY OF SWITZERLAND chap. Below Servoz the river again turns and enters another longitudinal valley. Further down on the right side between Combloux and Sallenches, M. Rendu long ago remarked with surprise that the cultivated ground rose to a certain height, and was then suddenly cut off by a belt of wood. This he found was due to a lateral mo- raine, the great blocks rendering cultivation impossible. It is one of the most remarkable groups in the Alps, and is probably due to its position just opposite the defile of Servoz, by which the great glacier descended into the valley of Sallanches. The moraine does not cease at Sallanches, but continues all down the defile of May- land. It exists, however, on the left side only. Not a single block of Granite occurs on the right anywhere in the whole defile. Why is this ? Rendu suggested the explanation. A smaller glacier from the Buet joins that of the Arve at Servoz, and con- tinues with it down.the valley. This affluent, however, came from a calcareous region ; the blocks forming its moraine, therefore, are undistinguishable from the debris which have fallen from the mountains, and are, more- over, more perishable than the blocks of Protogine com- ing from the Mont Blanc range. The whole plain between Cluses and the Sal^ve is covered with glacial deposit, and strewn with blocks of Protogine, except a calcareous band of very variable width extending from the opening of the valley of Bornand, by St. Laurent, La Roche, and Cornier, and ending somewhat to the east of Regnier. This is known as "Les Rocailles," is sterile and comparatively uncultivated. It is, in fact, a mo- raine belonging to the ancient glacier of the Bornand valley. Fig. 104 shows the fan structure so characteristic of the Alpine massives. The junction of the Crystalline Schists and the Pro- XVI THE MASSIF OP MONT BLANO 257 togine is well seen at Angle, on the edge of the Mer de Glace, above Montanvert. The schists become more Crystalline as we approach the Central Massif, and at the line of junction with the Protogine, can hardly be distinguished from true Gneiss. The Felspar is gener- ally white, sometimes rose. The Mica is white, brown, or black. The celebrated " Jardin " is an island of rock in the Glacier du Tal^fre. In the centre of the Plan des Dames, on the Col du Bon Homme is a cairn, on which it is the custom for every passer-by to place a stone, as is done in Jerusalem on the so-called Tomb of Absalom, and in so many other places. As usual in the Alps, the drop on the south side is more abrupt than that on the north, and the transverse valleys are consequently shorter. In fact, the moun- tains form a grand and almost continuous wall from Mont Blanc to the Aiguilles d'ArgentiSre. There are only two or three passes, and those very lofty. The Col de G6ant is that most frequently used. Of all the views in the Alps, says Forbes, few if any can be compared with that of the Mont Blanc Massif from Courmayeur. The moraines on the south of the chain are also very grand. The Cretaz de Saleinoz in the Val Ferret is one of the most magnificent in the whole Alps. It was the former right lateral moraine of the Glacier de Saleinoz, but is now quite detached from the glacier. It has a height of from 30 to 50 metres, and bears many immense blocks of Protogine. The polished surfaces of rock near the Glacier de Triolet, and of Mont Dolent reach a height of 2500 ■metres, that is to say, nearly to the Col du Petit Ferret. The moraine of Ivrea at the mouth of the Val of Aosta (see p. 85) is the greatest in the Alps, or indeed in Europe. CHAPTER XVII THE VALAIS The valley of the Rhone, from the Lake of Geneva to the Glacier, forms the Canton of Valais — the val- ley par excellence. The present valley from Villeneuve to the Gorge of St. Maurice was evidently at one time a part of the lake, and would be so still if it were not for the depos- its brought down by the Rhone. From Villeneuve to Martigny the Rhone occupies a transverse valley, cutting across the strike of the strata, which form a succession of complicated folds, the strata being often, as it were, brayed together, and sometimes vertical. They correspond on the two sides. The valley is, no doubt, of great antiquity. Favre and Schardt consider that it originally formed a narrow gulf of the sea.^ This view has also the support of Renevier's high authority, but seems to me, I confess, improbable. It has all the appearance of a river valley, but is no doubt very ancient, probably as old as the Mio- cene. It belonged originally to the Dranse de Bagne, and is most likely older than the upper valley or than the elevation of the Bernese range. It is indeed difficult to account for the facts, except by assuming that the Dranse was running approxi- mately along its present course before the folding at St. Maurice commenced, and cut back the ridge as it 1 Beiti: z. Geol. K. d. Schw., L. xxii. 258 CHAP. XVH THE VALAIS 269 rose. In this case, the Dranse is probably an older river than the Rhone, and to it properly belongs the valley between Martigny and the Lake of Geneva. Down to comparatively recent times the lower Val'ais was marshy, and subject to destructive floods. Hence, we find that the towns are generally placed on the cones oi the lateral streams, — Aigle on that of La Grande Eau, Bex at the mouth of the Aven§on, Mon- they of the Viege ; Muraz, Vionnaz, Vouvry, Aux Evou- ettes, etc., on the cones of other streams. The most remarkable cones are those (1) of the Bois Noir (Fig. 108), formed by the torrent of St. Barthdlemy, and y.-'AU'iaiii,: Sea level Fiu. 107. - Section across the Rhone Valley, showing the Cone of the Bois Noir. above Martigny; (2) that of Chamoson at the mouth of the Losenze, which is 4 km. in length, and rises from 480 metres to 730 metres, having therefore a height of 250 metres ; ^ and (3) the most striking of all, that of the Illgraben near Leuk. The amount of stones, etc., brought down by these three torrents has been so enor- mous as to dam back the river, and thus raise the gen- eral level of the valley for some distance above them. iKenevier, Beitr. z. G-eol. K. d. Sehw., L. xvi. 260 SCENERY OF SWITZERLAND chap. The plain of the Rhone valley where the river enters the lake is almost absolutely flat, but from Noville to Chessel are a number of undulations, and small hills, those to the west being the highest. At first they might be taken for moraines. They are, however, due to a great rockfall. The originally horizontal beds near No^dlle have been thrown into zigzags by the pressure of the fallen mate- rial. The scar, still known as the Derochiaz, is even now visible, immediately above Aux Evouettes. Mor- lot was inclined to identify this catastrophe with the great rockfall of 456 a.d., which, according to Marius d'Avenches and Gregory of Tours, overwhelmed the town of Tauredunum. Others, however, consider the Derochiaz fall to be more ancient, and point out that the fallen materials do not reach the foot of the moun- tain, but are separated by a stretch of absolutely flat ground. This they account for by supposing that the valley of Derochiaz was occupied by a small glacier, which acted as a sort of bridge, and over which the debris glided into the middle of the valley.^ There was a great rockfall from the Dents du Midi in 1835, producing a torrent of black mud which flowed down the St. Barth^lemy and covered the Bois Noir. Other rockfalls in this district have been already al- luded to. The rocky hill of St. Triphon, opposite OUon, must have been once an island. The sides plunge down almost vertically. There can be no doubt that the usual talus or scree exists at the base, but it is covered over by the alluvium, showing that the valley was a lake down to, geologically speaking, a very recent period. The bottom of the valley to a considerable depth con- 1 Favre et Schardt, Beitr. z. Geol. K. d. Schw., L. xxii. XVII THE VALAIS 261 sists of alluvium containing fresh water and sometimes land shells. The Navisance has cut 300 to 400 feet through gravel. On both sides of the Valais, marks of glacial action reach to a great height, and the upper limits of the ancient glacier can often be clearly traced. The gla- cial deposits in the lateral valleys are also of immense magnitude. The valley of Devens, between the Gri- onne and the Avangon, is especially remarkable in this respect, and contains many immense blocks. On the left bank of the Rhone a great moraine, which has been rendered classic by the labours and descrip- tions of Charpentier, extends, with some intervals, from the plateau of Verossaz above St. Maurice by Monthey to Muraz. It is almost entirely composed of Protogine from the north slopes of Mont Blanc. Some of the blocks are so large that they have received special names — the Pierre a Dzo, Pierre h Muguet, etc. At Bex are the celebrated Salt mines in the Trias, which have been worked for over 200 years, and were at one time managed by Charpentier, who resided at the village of Devens. The Dolomite and Gypsum, which are generally con- sidered to be Triassic, are especially susceptible to the action of weather and water ; hence the rivers (as, for instance, the Grand Eau), and the Cols (as, for instance, the Col de Pillon between the upper valleys of the Grande Eau and the Sarine, those of La Croix, Kinmeun, Frut- tlisspass, etc.) have a tendency to follow the outcrop of these strata. The Gypsum also often gives rise to swal- low holes, sometimes of considerable size. The little lake of Plambouit, which is said to be very deep, occu- pies one of these depressions.^ When the Gypsum oc- 1 Renevier, Beitr. z. Geol. K. d. Schw,, L. xvi. 262 SCENERY OF SWITZERLAND chap, xvii cupies high ground, it weathers into peculiarly pointed peaks, like those of the Dolomites. From the lake to Bex the valley is wide and open, but from St. Maurice to Martigny it is comparatively narrow, owing to the greater compactness of the rocks. Immediately below St. Maurice is a belt of dark, hard rock, belonging to the age of our chalk ; then come Crystalline rocks — the eastern extremity of the Ai- guilles Rouges Massif, with a synclinal containing Car- boniferous Puddingstone, and slate, which is worked near Vernayaz. A short distance above St. Maurice the torrent of St. Barth^lemy has formed the fine cone of Bois Noir (Fig. 107), and driven the Rhone to the foot of the Dents de Sea Level Fig. 108. — Section across the Rhone Valley at Martigny. Morcles. Fig. 108 gives a section across the valley at Martigny; it will be seen that the strata at the Pont des Martinets are reversed. The crystalline rocks consist of Chloritic schists, alternating several times with Mica schists. Prof. Gol- liez regards them as archaic sedimentary rocks much metamorphosed, but their age is still uncertain. They must be very ancient, for they are folded, and in his opinion this must have occurred before the deposition of the Carboniferous strata which lie unconformably upon them. If this view be correct we have here evi- La GiUe sur Charrat -• Valley of the Rhone near Fully Cote-de-Fully *'•" — rr. ' J ' ' Portrait de Fully — — ' -jwik Grand Chavalard "• — - Mont Bron -| \ \i^% Ool-des-Cornieules '^- !- Sex Treonhloz —-';-■ Grande-Dent — ~ Petite-Dent — - Riondaz'"-^ Raut-de-Morcle8 - - - V ""' 264 SCENERY OF SWITZERLAND dence of three great periods of disturbance, firstly, that of the Chloritic schists, secondly, of the Carboniferous strata, which overlie the schists, and thirdly, the great Cretaceous Nummulitic fold which forms the summit of the Dents de Morcles. Over St. Maurice on the west tower the magnificent Dents du Midi, which form so striking a feature in the view from the north side of the Lake of Geneva from Lausanne to Montreux, and are certainly among the most beautiful of Swiss mountains. The whole mountain has a torn and wild appearance. It is a part of the great Cretaceous Jurassic range which Fig. 110. — Section of the Dents du Midi. extends from the Lake of Walen, by Glarus, the Wind- galle, across the valley of the Reuss, through Ob Dem Wald, by Grindelwald, Lauterbrunnen, the Gemmi, to the Haut de Cry and the Dents de Morcles, which are a counterpart of the Dents du Midi, on the south- west. The strata, as shown in Fig. 110, are inverted; the older Neooomian resting on the younger Nummu- litic, which again reposes on Flysch. XVII THE VALAIS 265 For some distance on each side of Martigny, from Outre-Rhone nearly to Saillon, the bottom of the valley presents a number of Sand-dunes, first described by Mor- lot. They resemble in miniature those of the desert, and of some sea coasts. The most considerable are near Charat, and reach a height of 20 to 30 feet. They are formed especially in the spring when the Rhone is low, and leaves large sandy tracts uncovered. Shortly below Martigny ou the left side two streams enter the Rhone valley — the Sallanches and the Trient — but there is this remarkable difference, that while the Sallanches forms a beautiful waterfall, the Trient has carved for itself a deep and narrow gorge. The rocks over which they flow are similar, and apparently of equal hardness, and their difference is probably due, partly to the fact that the Trient draining a larger area, has a more considerable water power, and also that it brings down more pebbles and boulders, while the Sal- lanches is a clear stream.^ Most of the tributaries in this district enter the Valais through gorges more or less similar to that of the Trient ; those of the Lizerne, the Salenze, and the Triage are the most remarkable. The station of Vernayaz, at the opening of the gorge, which is well worth a visit, stands actually on the axis of the Carboniferous fold, and quarries of slate occur on both sides of the valley. They alternate with layers of Puddingstone. The Chloritic schists are well seen at the gorge of the Trient which is cut through them. From Martigny starts the great road over to St. Bernard, and Brockedon, who knew the passes well, assures us in a passage with which I entirely concur, that, besides the wildness of this Alpine pass, and the 1 Gerlach, Beitr. z. Geol. K. d. Schw., L. ix., p. ii. Favre, however, Eech. Geol, vol. ii. seems to indicate tliat tlie strata through which the Trient runs yield rather more easily to water action. 266 SCENEEY OF SWITZERLAND beauty of the valley of Aosta, through which the road to Turin continues after it leaves the mountains, " the kind reception which the traveller experiences from the religious community at the hospice on the summit of the St. Bernard, is remembered as long as he can be grateful for the devotion which induces these excellent men to offer to the travellers their welcome, and spread for him their hospitality in the wilderness." At Martigny the Rhone turns at a right angle. In fact it leaves the great longitudinal fold and enters a transverse valley properlj;- belonging to the Dranse. During the Ice age the ancient glacier in making this N. W. Fig. 111. — Face of the Rock from S.E. to N.W. at Martigny. sharp turn pressed with enormous force against the rockface opposite Martigny, which is tremendously worn and polished, affording in Ruskin's opinion the most remarkable illustration of ice action to be found in the whole Alps. Above Martigny we come to the true Rhone valley — the only part of its course which really belongs to the Rhone, for the valley below Martigny originally belonged to the Dranse, that below Belle- garde to the Valserine, and below Lyons to the Saoue. The valley from Martigny to Oberwald is a longitu- dinal valley of geotectonic origin, due to a fold created XVII THE VALAIS 267 during the elevation of the ,\lps. This great fold stretches west by Chamouni and the Isdre to Chamb^ry, eastwards by the Urserenthal and Rhine valley as far as Chur, reappearing indeed still further to the east. At Martigny itself the strata are nearly vertical (Fig. 111). The old Tour de la Batiaz stands on a narrow band of Jurassic rock, which extends west over the Col de Balme to the valley of Chamouni, and eastwards up the valley of the Rhone. It is a continuation of the great synclinal of Chamouni. For some distance above Martigny the valley of the Rhone was evidently once under water. M. Renevier Fig. 112. — Transverse Profile ol the Gorge of the Lizerne. considers that it was a distinct lake from that of Geneva, separated by the ridge at St. Maurice, but M. Forel has clearly shown that there was a time when the waters of the Lake of Geneva stood at a much higher level than the present, and they must then have been extended far up the Rhone valley. The present level of the lake is 375 metres,. the Rhone valley between Monthey and Bex is 400 metres, Martigny 460, and Brieg 670. The bottom of the valley is, however, raised by the alluvial deposits, the thickness of which is not known. When, therefore, the lake was at its highest it possibly extended to Brieg, though at another time the part above Mar- tigny may very likely have formed a separate and upper 268 SCENERY OF SWITZERLAND lake. To the east of Martigny is another belt of Crys- talline rocks, while some little distance up the Dranse, at Sembrancher, we come again upon Jurassic, the east- ern prolongation of the Jurassic synclinal of the Val Ferret. The valleys of Liddes and Chable owe their origin to the softer Carboniferous (Anthracitic) strata. XVII THE VALAIS 269 Fig. 112 represents a section of the valley of the Lizerne, which falls into the Rhone at Ardon below Sion. The above section, Fig. 113, shows the remarkable contortions of the strata on the great south wall of the Diablerets seen from the Tour d'Anzeindaz. The sum- mit here marked as Pointe de la Houille is perhaps more generally known as the TSte Ronde. The next figure (Fig. 114) represents a section from north-north-east to south-south-west. This " lying fold " is a remarkable case of complete inversion. The chain of Argenti^re between, but somewhat west Toinle de la ffoaille 30i3'.' HI — Fig. 114. — Section of the Wall of the Diablerets. of, the Diablerets and the Haut de Cry is formed of vertical Urgonian strata, and when seen in profile, seems sharp as a knife-edge. At the Lion d'Argenti- Sre, so called from a fancied resemblance to a crouching lion, the strata are also inverted, so that the summit is formed by reversed Urgonian resting on Neocomian, Nummulitic, and Flysch. Nearer to, and more conspicuous from, the Valais is 270 SCENEKY OP SWITZERLAND another great rock wall, that of the Haut de Cry. Fig. 115 shows the folds of the strata, which, if the light suits, may be clearly made out from the valley. Above Martigny one sees clearly the contact of the Calcareous and Crystalline rocks on the north of the valley grad- ually descending towards Saillon. Sion owes its picturesque and feu- dal aspect, and indeed, its impor- tance in mediaeval times, to the fact that the river has left several masses of native rock, on which three castles were built. The highest was formerly the Bishop's Palace, built in 1492, but now a ruin. Just above Sion the Borgne has formed a fine cone, and driven the Rhone to the foot of the oppo- site mountain. At and round Sierre we find the remains of the most gigantic rock- fall in the whole of Switzerland, excepting that of Flims in the val- ley of the Rhine. It extends from Pfyn almost to the mouth of the Liena, and has a width of about a mile. It must have long dammed up the valley, but is now com- pletely cut through both by the Rhone and by several tributary streams. The surface is very irregular, in many places reaching a height of 70, 80, at Geronde even 100 metres above the river level ; further westwards it gradually diminishes. The irregu- larities of surface have given rise to several small THE VALAIS 271 lakes, the largest of which, a little north of Geronde is 450 metres long, 100 to 150 broad, lies 3 metres below the level of the Rhone, and has a depth of 8 to 10 metres. The banks are very steep. The landslip took place above Cordon, under the Varener Alp. It was prehistoric, bxit must have taken place after the retreat of the great glacier. A beautiful bronze sword was found in a grave on the hill of Tevent, below Sierre, showing that the fall was before the Bronze age. Opposite Leuk is the grand cone of the 111, which has again driven the Rhone to the north side of its valley, and to some extent dammed back the river. The valley Sea level Fig. 116. — Section across the Haut de Cry, and the Valley of the Lizerne to the Rhone. of the 111 — the lUgrabeni — affords one of the most striking instances of recent rapid denudation with which I am acquainted, and is well worth a visit. Between Turtmann and Raron well-marked lines may be seen on the north side of the valley. These are " Bises " or artificial water-courses, and are fringed with lines of trees. The north side being most exposed to 1 Murray's Handbook, though as a rule marvellously accurate, gives the lllgraben as a case of rockfall. 272 SCENERY OP SWITZERLAND chap. the sun is comparatively dryer and more bare than the south, which is greener and well-wooded. The side of the valley above Gampel is much smoothed and rounded. Many of the lateral valleys, for instance, on the south side those of Iserable, Nendaz, Herins, Reschy, Anniv- iers, Turtmann, and Ginanz, though broad in their upper parts, open into the main valley by narrow, and often, inaccessible gorges. Similar cases also occur on the north side. The gorge of the JoUibach at Nieder Gestelen (Jolebach on some maps) is 200 to 300 metres deep, and in places only a few metres in width, cut through Calcareous rock. It is quite inaccessible, and in its great height as well as in its extreme narrowness almost equals the celebrated gorge of the Trient. Prof. Desor proposed for such gorges the special name of " Roflas." Between Gampel and Karon the synclinal fold which has given rise to the Rhone valley divides ; one branch diverges northwards through the Aar massif in the direction of the Aletsch glacier, the other has deter- mined the line of the river. The Swiss geological maps do not, unfortunately, show this very clearly, because the country north and south of the valley were mapped by different observers, and the strata are coloured differently. There was, more- over, at first much, and is still some, difference of opin- ion as to the age of the Schists on the south side of the Rhone from Turtmann to Grengiols, which are coloured light brown on Studer and Escher's map, violet on that of Heim and Schmidt, and dark brown on sheet 18 of the great Dufour map. These Schists are now generally regarded as Jurassic, and of the same age as the Jurassic strata on the north, which are coloured blue and violet. THE VALAIS 273 The valley is in fact a trough of Jurassic strata lying between the older Crystalline rocks of the Aar massif on the north, and of Monte Leone on the south. The Aar massif is not, however, a simple arch, but is composed of several folds. The north side of the Rhone from Gam- Eothe Zul Alp Bij^schsrcu BaltseUedertliiil Rhone Se;<3«.R,J. A.G. Fig. 117. — Section of the Rhone Valley at Visp. Gr. Granite ; Gn. Gneiss ; A.G. Eyed Gneiss ; Ser. Gn. Sericitic Gneiss ; Li. Lias ; J. Jurassic. pel to Nieder Gestelen is cut down to the Gneiss ; from Meder Gestelen to Baltschieder is a trough of Jurassic, at Baltschieder the Gneiss appears again. At Mund the trough, which is somewhat to the south of the river, and dips to the south, again divides, and the ¥a3eil]i9 Jil.Canieri CrtH^ Gneiss c> Cranitc T ^^B 7"?-/as J Lb^ 7Krajj/c Fig. 118. — Section of the Ehone Valley near Brieg. two branches diverge ; the southern takes the line of the Binnenthal, the Gries glacier, and the Bedrettothal, itself subdividing again on the way. Fig. 118 gives a section across the valley at Brieg. The northern syn- 274 SCENERY OP SWITZERLAND clinal has given rise to the valley of the Rhone, which follows its course. Fig. 119 gives a section at Viesch. Denudation has here entirely removed the Secondary strata, though we may be sure that they must have formerly existed since we find them along the valley both above and below. At Nieder Gestelen also is an old frontal moraine of the Rhone glacier, evidently deposited during its last retreat. The valley of Zermatt, vi^hich opens at Visp, lies mainly in Schists, the exact age of which is still un- Helseihr' M.Moro viesch cAlUlA Gneiss &= Granite tW^Ttios 'xSZljurassic Fig. 119. — Section of the Rhone Valley at Viesch. determined, but at Baarmiihle there is a mass of Ser- pentine. The strata at Zermatt itself are considered to be Triassic. The gorges of the Gorner resemble those of Ragatz or of the Trient. The rock forming the upper part of the Matterhorn, is nearly horizontal, inclined slightly downwards towards Monte Rosa. Heim regards it as an overlying fold of Gneiss. It is a ridge like those of the Gorner Grat and the Rumpfischhorn, and probably preserved by its position, and perhaps by being specially hard. The base is of Crystalline Schists lying on Trias. On the west side is a wedge of granitic Euphotide. The village of Randa has been several times over- whelmed by avalanches. XVII THE VALAIS 275 The Saasthal, which joins that of Zermatt at Stalden, is also wonderfully beautiful. Saas Fee and Zermatt are, however, so different that they can hardly be compared. The inhabitants of the upper Italian valleys to the south of Monte Rosa have a widespread tradition of an enchanted valley, beautiful and rich, which once existed in the heart of the mountain, and has now disappeared. It is probable that the view of the Zermatt valley from the heights of Monte Rosa originated the idea of the lost valley ; and certainly the more one sees of it the more enchanting it is. If, as we ascend the Simplon route from Brieg, we look across to the Baltschiederthal on the opposite side of the Rhone valley, the contrast between the rounded outlines of the glaciated rocks below, and sharp jagged ridges of the Genthorn and the Gredetschhorn, the Hohen Egg, is very striking. From Baltschieder to Morel, with a small exception at the mouth of the Massa, the north side of the Rhone is Gneiss, while the south is Mica Schist. At the en- trance of the Massa, however, and perhaps owing to its influence in bygone ages, the Rhone seems to have been forced somewhat to the south. However this may be, it has cut through the Mica Schist leaving a mass on the north side, which is bisected by the Massa. For some distance above the mouth of the Massa the valley is occupied by the debris of rockfalls. The blocks are scattered in wild confusion, and some are as large as cottages. The Valais contains also several ancient moraines, one east of Filet opposite Zenhausei'n, and a larger one between Lax and Wyler; but the most imposing is that east of Viesch. It partly forms the Gibelegg, forces the road to make several zigzags, and bears the 276 SCENERY OF SWITZERLAND chap. village of Fu-rgangen, extending towards Bodmeu in the Viescherthal, and Belwald in the Valais. There is another large moraine at Ulrichen. In the centre of the village of Biel is a great erratic block. Above Biel the road crosses a great mound long grown over and covered with beautiful fields and meadows, but evidently the result of a prehistoric rockfall. The deep gash from which the mass fell is still clearly visible above Ritzingen. Near Reckingen are remains of several ancient mo- Cr.Sidelli^ _.. -,„ RitzcnliJ Rothh? HoisandL" Ofeth"^ Cr\ii It'll Gneiss &= Granite tW/^ Trias d 12S] TVirasjiV Fig. 120. — Section of the Rhone Valley at Ulrichen. raines, and at Miinster another great rockfall, with its corresponding hollow like that of Ritzingen. From Biel to Oberwald the lateral streams form a succession of cones, which drive the Rhone from one side to the other, and form marshy places by damming up ihe valley. Miinster is built on a specially large one. At Ulrichen Calcareous and Dolomitic rocks reap- pear; they are the continuation of the fold in the lower part of the valle}"". From Baltschieder to Ul- richen, however, they have been removed by denuda- tion, which has cut down to the Crystalline rocks. Above Oberwald the true continuation of the val- ley is up the little stream of Gingis. The larger one, XVII THE VALAIS 277 which comes down from the glacier, is really a trans- verse affluent, but from its greater size is regarded as the source of the river. In the wood through Vhich the road rises from Oberwald to the glacier the rocks have been much worn and rounded by glacial action. Just before arriving at the hotel the road enters another longitudinal valley, in which lies the beauti- ful glacier of the Rhone (see Frontispiece). At pres- ent the front of the glacier is about 20 minutes' walk from the hotel, the intermediate plain being an inter- esting illustration of fluvioglacial deposits. Like most of the Swiss glaciers that of the Rhone retreated during the first ten years of the century, after which it advanced and in 1820 reached within 150 metres of the houses at Gletsch, where it formed a small terminal moraine. From 1822 to 1844 it again retreated ; then commenced another period of advance, and in 1855-60 the front was within 100 metres of the moraine of 1820. From that time it has again re- treated. Shortly above the hotel is the moraine of 1820, form- ing a well-marked, curved ridge, which stretches across the valley, except where it has been cut through by the river. About 100 metres further is the moraine of 1855-60, which was the terminal moraine of the glacier when I first saw it. Then follows a stretch of irregu- lar moraine matter, showing in miniature the same ir- regular heaps which on a large scale we find near the moraines of the ancient glaciers. It is interesting to notice the difference between the angular rocks which have fallen with avalanches from the sides of the val- ley, and the rounded blocks which have been brought by the glacier. The larger of these often show a marked difference on the two sides, being (Fig. 36) 278 SCBNEKY OF SWITZERLAND chap, xvii rounded on the side turned to the glacier, and rugged on the other. Some of the blocks have evidently been pushed along by the ice, leaving a furrow behind, and making a little mound in front. The river leaves the glacier in many streamlets, but mainly issues from a beautiful blue arch, now (1895) nearly in the middle of the glacier face, and some 25 metres high. The lower glacier is somewhat spoon- shaped, with radiating crevasses. Above it is a fine icefall, of which a splendid view is obtained from the road over the Furka; above the fall is a flat expanse of ice, ending in a great snowfield. The Furka is a deep trough with gneiss on each side and Jurassic strata in the centre, marmorised by pressure, and containing Belemnites and Pentacrinites. The synclinal is continued along the Urserenthal, and goes deep down, having been found with little change in the tunnel of the St. Gotthard Railway. CHAPTER XVIII THE BERNESE OBERLAND The Bernese Oberland seems at first sight a chaotic wilderness of mountains and valleys, snowfields, and glaciers, without any plan or regular arrangement. The more however the district is studied, the more the details are ascertained, the more do difficulties and anomalies disappear, and the points which still remain a mystery will doubtless be explained by future obser- vations. The Aar massif may be described as an ellipsoid mountain mass, running from S.W. to N.E. ; bounded on the N.E. by the Upper Reuss ; on the S.E. by the Urserenthal and the Rhone from its source down to Leuk ; on the N.W. by the great wall of the Bernese Oberland; and on the S.W. by the valley of Leuk. These lines of demarcation, however, though practical and convenient, are, it must be remembered, somewhat arbitrary. The valley of the Reuss is a transverse val- ley of erosion, cut out by the river, and the rocks on both sides are identical; it corresponds to no difference of geological structure. The valley of the Rhone is, on the contrary, a " geotectonic " valley, due to a great fold in the strata, but still geologically speaking of but recent origin. The great Bernese Oberland wall (Fig. 121) is an escarpment due to the weathering back of the Jurassic strata; and the valley of Leuk, like that of the Reuss, is a transverse valley of erosion. 279 280 SCENERY OP SWITZERLAND chap. Though the Aar massif is detached, it is no isolated phenomenon. The Protogine, which forms its nucleus, is mineralogically and chemically identical with that of Mont Blanc, and it is obvious that these two mountain masses are merely two upthrows of the same central rock. Atmospheric influences and the agency of water have cut the slopes of the longitudinal ridges into deep val- leys, thus forming transverse ridges, which again are carved by denudation into separate summits. These ridges, therefore, form N.W. and S.E. chains, as for instance on the west of the massif, the ridge which runs from the Bietschhorn to the Dubihorn, or from the Nesthorn to the Faschhorn and the Gredetsch- horn ; and on the east from the Schreckhorn and Lau- teraarhorn. The whole massif may be considered as the root or stump of a gigantic arch, itself thrown into a number of folds and troughs. The centre of the whole district is the majestic Finsteraarhorn, the monarch of the Bernese Oberland. To the N.E. are three main longitudinal valleys, indicated by the Gauli glacier, the Unteraar glacier, and the Oberaar glacier ; and to the S.W. the great Aletsch glacier, the Aletsch Firn, the Upper Lot- schen Thal,i and the Kander Firn. The Granite and Gneiss as mentioned above (^ante, p. 228) shows a very complex structure, and the Cen- tral Gneiss presents a well-marked "fan arrangement." Fig. 121 gives a section from the Kleine Doldenhorn across the Gasteren Thai and the Lotschen Thai, show- ing that the first is an anticlinal, the second a synclinal. The Kander Firn and Tschingel Firn lie in an anti- clinal valley. The Dala to the east of Leukerbad is also 1 The lower part of the Lotschen Thai Is a cross valley. THE BEENBSE OBERLAND 281 cut down between the Lias and the Upper Jurassic, the latter forming an escarp- ment. The longitudinal valleys are, however, for the most part syn- clinal. The Aletsch is the greatest of all Swiss glaciers. It is 15 miles in length and covers 50 square miles. It commences with a great snow sheet, the Grosse Aletsch Firn, the lower or N.W. end of which is known as the Concordia Platz. From this immense central snowfield ra- diate the Jungfrau Firn to the N.W., the Ewigschnee Feld to the north, and the Aletsch glacier to the S.E. The view from the Grosse Griinhorn is peculiarly arctic, for though it is very extensive, scarcely any trace of green is visible. The Miirjelen Thai 282 SCENERY OF SWITZERLAND chap. falls in about the centre of the Aletsch glacier on the south side. If there were no glacier, the stream from this valley would join that of the Aietsch valley. The Aletsch glacier, however, occupies the great valley, and dams back the water of the lateral stream. The side of the glacier forms a cliff, 150 feet in height, and rising some 50 feet above the level of the Marjelen See. From this cliff great masses are detached from time to time, which float as miniature icebergs in the lake. To prevent the water from rising too high a channel has been dug, which carries off the surplus down to Viesch. Every few years, however, some change in the glacier lets out the lake, which rushes under the ice down the Massa valley. The Marjelen See is quite unique. The pure white of the icebergs, the deep blue of the lake, the precipice of ice, the glacier, the green meadows and the surrounding mountains, make one of the most beautiful and extraordinary scenes in the whole Alps. The view from the summit of the Eggischhorn has long been celebrated for its extreme beautj^ The Lotschenthal district is one of the most interest- ing and instructive regions in the whole Alps, and the contortions here attain their greatest complexity. The ridge of which the Ferden Rothhorn, the Resti Rothhorn, and the Faldum Rothhorn form three sum- mits, is especially remarkable. In Fig. 122 we see that the strata are very steeply inclined, and form a com- pressed synclinal fold, itself again several times folded. The centre of this trough now forms the summit of the Ferden Rothhorn. Though now therefore rising into mountains, they are really a closely compressed and folded trough .1 1 Fellenberg, Beitr. z. Oeol. K. d. Seine., L. xxi. THE BEENESE OBERLAND 283 Fig. 123 representing the upper part of the Faldum Rothhorn gives a vivid idea of the compression, con- FiG. 122.— Theoretical Section tlirough tiie Ferden Eotliliorn from Nortli to Soutli. tortion, and crushing which the mountain has under- gone. The remarkable, and long inexplicable, fact that on Fig. 123. — Section oi the Faldum Rothhorn. the Jungfrau and the Monch the far more ancient gneiss overlies the Secondary Calcareous rock, is due to the existence of these great folds in the strata. The west flank of the Jungfrau, as seen from the 284 SCENERY OF SWITZERLAND chap. Ebnefluh, shows a great band of Calcareous rock lying on and covered by gneiss. The Plate representing the Jungfrau seen across the valley of Lauterbrunnen shows the gneiss (pink) over- lying the Jurassic (blue), in which are folded two wedges of Eocene (yellow). This remnant of Jurassic rock, originally overlying, but now folded into the gneiss, can be traced from the Jungfrau to the Petersgrat, on the northern flanks of the Ebnefluh, the Mittaghorn, Grosshorn, Breithorn, and Tellispitzen. It does not, however, extend through the mountain, but is, so to say, a wedge folded into it. Moreover, the wedge is itself folded, and contains two inner wedges of Eocene rock, which reappear near the hotels at Miirren, on the other side of the Lauterbrunnen valley. Seen from the north the mountain appears as a wall of Calcareous rock, with a summit of gneiss. The total height is 4167 metres, of which about 800 metres is gneiss, the base being Upper Jurassic. The structure of the Monch^ is simpler but it also belongs to the region of overfolded gneiss, which has a thickness of 900 metres resting again on the Jurassic. The upper surface of the Calcareous rock is not horizon- tal, but inclined at an angle of about 20°. In both cases the cap of gneiss is part of the great fold, and was originally continuous with the gneiss to the south and south-east. The Eiger, on the other hand, is a typically Calcareous mountain. In the case of the Jungfrau the fold has a depth of 3 km., at the Monch of 1^, and in this distance the older and underlying gneiss has been regularly folded over, so that it now lies upon the- younger and originally iBaltzer, Beiti: r,. Geol. K. d. Schw., L. xx. Jungfrau Silberhorn Schwartz Monch Eocene Lauterbrun nen. ; CO) r % lam y y tf n g f r a u . THE BERNESE OBEELAND 285 upper strata. The Jungfrau wedge is regarded by Heim as the western continuation of the fold of the Windgalle. It had been supposed by some authorities that the gneiss was thrust over the Jurassic, but Baltzer is clear that the inversion is due to folding and not to overthrust. Ctl ^Gneiss. T. .Trias: J. fttrassi^ E. Moeene, Fig. 125. — Sketch Map of Meiringen District. In some cases the Calcareous rock seems to be forced into the gneiss ; this, however, is due, not to eruption, but to kneading' and squeezing. Further to the west these great folds are well shown in the valley of the Aar. At and above Meiringen (see map), the valley is excavated through the Jurassic strata, in which the celebrated gorge of the Aar has been cut 286 SCENERY OP SWITZERLAND chap. through a belt of rook known as the Kirchet. Immedi- ately above the Kirchet is a narrow band of older (Trias- sic) Sedimentary rock, and then we come to gneiss, the line of junction having the usual south-east and north- west direction. Further up the valley, however, is a second belt of Jurassic age, capping the Laubstock on the west and the Pfaffenkopf on the east, but cut through by the valley ; while still further up, but at a greater height and consequently further from the val- ley, there is a second narrow band cropping out at the Bettlerhorn on the west, and the Stiergrund on the east, while the Schonalphorn, the Benzlauistock, and the whole district beyond are gneiss. The Jurassic strata originally covered the gneiss, and according to Baltzer they were thrown into folds, and these two belts of Jurassic are two of the wedges formed by the folds. Similar folds are shown in Fig. 120, but in that case have not been eroded. The valley itself, except just at Urweid, is on gneiss, above the gneiss is Jurassic, and over that gneiss again. The same arrange- ment is well seen in the Urbachthal which joins the main valley at Hof. It is one of the most beautiful, as well as most interesting, in the whole district. The bottom of the valley is of gneiss, the west side (Engelhorner) is Jurassic, rising to a height of 1900 metres ; the right gneiss with however three bands of Jurassic (Malm) (Fig. 125) ; these are really the remains of folds as shown in the figure. On the Gstellihorn there are actually five of these wedges or folds. It is in this respect the most re- markable case in the district. The line of junction of the gneiss and the Calcareous rock is perfectly clear and sharp, so that the hand may cover both kinds of rock at the same time. There is absolutely no trace of any intermediate layer, such as xviii THE BERNESE OBERLAND 287 marble, nor any change in the character of the Calcare- ous rock.i It is evident, therefore, that the schists and Sedimen- tary rocks have not been actively broken through by the granite and gneiss, but that they were deposited on them, all three having been passively and simultaneously thrown into folds. The great wall of the Bernese Oberland (Fig. 121), which stretches eastwards from the Gemmi by the Balm- horn, the Doldenhorn, the Bliimlisalp, the Eiger, the Urbach thai Engelhorn Schonalphiirn 8025 ft. Gneiss Fig. 126. — Section showing the Calcareous VTedges of the Schonalphorn in the Urhachthal. Mittellegi, the Scheideck, the Gadmer Fluh, and the Schlossberg to Erstfeld on the Reuss, with a nearly perpendicular height of 1000 metres, is in fact the es- carpment of the Secondary rocks, which formerly cov- ered the whole massif. That these Secondary rocks once extended further south is clear from the dip of the strata (Fig. 121). Moreover, some fragments of the Secondary strata 1 Fellenberg, Beitr. z. Geol. K. d. Schvj., L. xxi. . 288 SCENERY OP SWITZERLAND chap. still remain preserved in the deepest folds. At both ends of the ellipse Jurassic strata run up for some distance, as for instance, on the the west the Jurassic belt which quits the Valais at Raron and runs north- east by St. Germain, Leiggern, and the Kriiliggrat towards the Hohe Egg. To the east and west, however, these are cut off by- denudation. Along the northern border of the gneiss, a series of Jurassic rocks extends at intervals from the Ferden Rothhorn by the Tellispitzen, on the flanks of the Breithorn, by the Ebnefluh, the Jungfrau, and Monch. More in the centre of the region another line com- mences with the Blauberg,! so called from the bluish Jurassic rock, which makes a striking contrast with the surrounding Crystalline region, at Farningen in the Meienthal, at Rothbergli, and at Staldi in the Intschithal.^ Lastly on the south comes the Jurassic fold of the Upper Valais. Another evidence is that the northern transverse valleys instead of tapering to the ridge, run boldly up to it, as for instance the Gamchi glacier at the head of the Kienthal. Indeed, though the great wall is unbroken, blocks of granite and gneiss, which must have come from the central massif, are found to the north of the wall. The amount of denudation has therefore been enor- mous. The central peaks of gneiss and granite-gneiss, the Bietschhorn, Gr. Nesthorn, etc., tower up to a great height; but in our imagination we must replace on their summits, not only beds of Crystalline schists, such as those which form the Tschingelhorn, the Breithorn, and the Finsteraarhorn itself ; but over this again we have 1 On some maps it is marked as the Greissenhorn. 2 Baltzer, Beitr. z. Geol. K. d. Schw., L. xxi. XVIII THE BEENESB OBEELAND 289 to pile the whole series of the Secondary strata, whose enormous thickness the great wall of the Bernese Ober- land enables us partly to idealise. Like the Titans of old we must pile Ossa on Pelion in our imagination, and realise that as in the Greek myth, so also here it has been stripped off by the powers of the air. The present configuration of the surface is therefore mainly the work of denudation, and while the longitu- dinal valleys are on the whole tectonic, the transverse or cross valleys which cut into and in some cases almost across the massif, the Trift glacier, the two Grin del wald glaciers, the Aar, the Reuss, etc., are valleys of erosion. The highest peaks are sometimes due to the greater hardness of the rock; sometimes, and perhaps even more, to the accident of their position, which has ex- posed them less to the action of erosion. The Aar massif, as Baltzer says,^ is in fact a gigantic torso. Indeed, any one who carefully considers the great wall of the Gemmi, or of the Bliimlisalp, towering over the valley of Leuk and the Kander Firn, will be con- vinced, that the Jurassic strata form the north limb of a great arch extending southwards. These remarkable folds throw some light on the mag- nificent scenery and grand proportions of the Bernese Oberland. The Jungfrau and Monch owe much of their beauty to the combination of gneiss and Calcareous rock. These, indeed, are exceptional instances, but the height is probably in great measure due to the extreme amount of compression and folding which has taken place. The enormous depth of the comparatively nar- row valleys is another remarkable feature of the district. The steep precipices of the Wetterhorn have a height 1 Beitr. z. Qeol. K. d. Schw., L. xx. 290 SCENERY OF SWITZERLAND chap, xviii of 2000 metres. This also is greatly due to the same cause. The Calcareous rock (Hochgebirgskalk) which forms the lower part of the mountains is very inflexible. Folding might indeed take place at great depths, but near the surface there would be innumerable rents and fractures, which would reduce it almost to the state of a breccia, and leave it a comparatively easy prey to atmospheric influences. CHAPTER XIX THE UPPER AAR The Upper Aar from its source to the Hospice occu- pies a longitudinal valley. It is fed by the two great glaciers known as those of the Oberaar, and Unteraar. The Unteraar glacier which is about nine miles in length and two broad, has, from its considerable size and level surface, been selected for many scientific ob- servations. As long ago as 1827, Hugi built a hut on it, the remains of which were found by Agassiz in 1840, having moved forward about 4600 feet. In 1841, Agassiz himself built another hut on the glacier, long known as the Hotel des Neufch&telais. A peak visible from the Hospice has been named the Agassizhorn, in recognition of his valuable researches. At the Hospice the Aar turns northwards at a right angle into a cross valley. The rocks here, and down to Handeck, are remarkably glaciated, and the contrast between the lower portion smoothed by the glacier with the rugged and jagged rocks above is very marked. At Handeck is the magnificent Fall of the Aar, cer- tainly one of the finest waterfalls in Europe, from its height and the volume of water, the gloomy gorge into which it falls, and the wild character of the whole scenery. Moreover the effect is considerably enhanced by the fact that another stream, the Handeck or Erlen bach, coming from the west, falls into the same chasm ; and that from about ten o'clock to one in the day the spray reflects a beautiful rainbow. 291 292 SCENERY OF SWITZERLAND chap. The fall of Handeck is not, like so many others, a series of cascades, but the river leaps over with a single bound. This is due to the presence of a hard ridge of granite, which projects beyond the softer Gneiss-granite, and Eyed-gneiss. Below Handeck and as far as Guttannen is a broad belt of Sericitic Phyllite. At Guttannen the Gneiss re- appears and continues as far as Innertkirchen, broken however by another band of Phyllite at Urweid, and by the Jurassic folds already mentioned (ante, p. 286). At Innertkirchen the Gneiss dips under the Triassic and Jurassic strata, the former represented by a narrow belt, the latter forming the continuation of the great wall of the Bernese Oberland. Near the junction of the Gneiss and the Jurassic strata the Aar crosses a longitudinal valley, known as the Urbachthal (see ante, p. 286) on the west, the Gadmenthal on the east. In both cases the lateral valleys are at a higher level than that of the Aar, following the general rule that trans- verse valleys are excavated more rapidly than longi- tudinal ; and the result is in each case a sharp rise from the Aar valley, that of the Urbach being the steeper of the two. Below Innertkirchen the valley of the Aar is inter- rupted by a ridge of Jurassic rock, known as the Kirchet, above which it has been supposed that the river once formed a lake in the depression known as "Hasli-im Grund." Of this, however, there is no direct evidence, and it is possible that the river cut through the ridge as it rose. Studer^ was disposed to regard the depression as due to an earthquake. In fact, however, it simply follows the normal slope of the river. The Aar has cut for itself a magnificent gorge, 300 to 400 feet deep, one ^ Qeol. d. Schweiz., vol. i. XIX THE UPPEK AAR 293 of the longest and deepest in Switzerland. At both ends the rocks are much glaciated. Near the upper end is a water-worn channel, which runs down by a steep path to the present river level. This is an old course of the river. The gorge of the Aar used to be regarded as due to fracture, but the whole section has evidently been cut by the river, and the characteristic marks of river erosion occur from top to bottom. Below Meiringen the river flows through a broad flat valley, which was evidently once much deeper, and formed part of the Lake of Brienz. On each side are bold walls of Jurassic rock, with well-marked weather- terraces. As in other cases it is evident that the lake formerly extended some distance up the valley, in the present instance as far as Meiringen, and that it has been gradually filled up by the river. The Lake of Brienz is 9 miles long, 2 wide, 566-4 metres above the sea, and 305 in depth. The lake fol- lows the line of junction of the Cretaceous strata on the north, with the Jurassic on the south. Both sides are precipitous, and the celebrated falls of the Giess- bach are near the east end, opposite Brienz, where the stream in a succession of cascades descends the steep wall of Jurassic strata. The ridge on the north is Neocomian capped by Urgonian. The Lakes of Brienz and Thun were originally one, and the level plain upon which Interlaken stands has been formed by the deposits of the Liitschine coming from Grindelwald on the stiuth, and of the Lombach which drains the valley of Habkern on the north. To judge from the depth of the lake, these deposits must be at least 1000 feet in thickness. It is said that until the fourteenth century the Liitschine ran into the Lake of Thun, and interfered with the outflow from the Lake 294 SCENERY OF SWITZERLAND CHAP. of Brienz, giving rise to an unwholesome marshy plain, and that the nuns of the Convent of Interlaken turned it into the Lake of Brienz. The Aar on the plain of Interlaken follows a winding course, being first diverted to the right by the cone of the Liitschine, and then to the left by that of the Lombach. The original lake, before it was divided by the formation of the plain, passed through a narrow gap in a fractured and dis- placed Neocomian ridge, very like that which nearly bisects the Lake of Lucerne at the two Nasen. The position of the Lake of Brienz like that of so many other longitudinal valleys has probably been de- termined by its being the line of junction between two formations. Grindelwald rests on a rockfall from the Rothihorn, which occupies almost the whole bottom of the valley .^ To the S.E. of the church, however, a ridge of Dogger comes to the surface ; while to the S.E. of the debris, and at the edge of the Jurassic (Malm), a narrow band of Flysch extends N.E. to Meiringen. The Grindelwald glacier formerly descended lowest of all the Swiss glaciers, the end being in 1868 only 1080 metres above the sea. Of late years, however, it has considerably retreated. From Grindelwald the wall of the Oberland passes west to Meiringen over the Grosse Scheideck, and east to Lauterbrunnen over the Kleine Scheideck. At Lauterbrunnen is the beauti- ful Staubbach waterfall, one of the highest in Europe, the fall being between 800 and 900 feet. The height being so great and the volume of water comparatively so small, it is shivered into spray before reaching the bottom, whence its name, the Dust Stream. "It is," says Byron, " in shape, curving over the rock, like the ' Moesch, Beitr. a. Geol. K. d. Schio., L. xxiv. THE UPPER AAE 295 tail of a white horse streaming in the wind — such as it might be conceived would be that of the ' pale horse ' on which Death is mounted in the Apocalypse. It is neither mist nor water, but a something between both ; its im- mense height gives it a wave or curve — a spreading here or condensation there, wonderful and indescribable." ^ The Lake of Brienz occupies a longitudinal valley. Fig. 128 shows a section from north to south ; from Guggenhiirli across the Habkern valley and the Harder i a Berrias Layers Lower Cretaceoits Fig. 127. — Section across the Justitlial. ridge to the Aar near Interlaken. It will be seen that the valley of Habkern is a valley of erosion, and that the Harder and Rieder Grat is formed by Urgonian, Neocomian, and lower Cretaceous (Berrias) strata curv- ing upwards towards the lake over the present site of which they must at one time have formed a great arch. The present south edge of these strata is not their orig- inal boundary. They are not the shore of the creta- ceous sea, but were formed in a sea which at one time stretched far to the south. The lower cretaceous beds in fact reappear in patches and bands along a belt run- ning from near Gsteig, parallel to, but some distance 1 Byron's Journal. 296 SCENERY or SWITZERLAND south of the Lake ; and the Eocene along another belt, from the Bay of Uri, by Meiringen, to Grindelwald. These must not be regarded as deposits foi'med in bays or fjords, but as remnants of once continuous deposits. The valley of Habkern is also celebrated for many fragments and blocks of red granite, known as Habkern granite, which occur also in other neighbouring valleys, but are here particularly numerous. One of them at- tains a size of 400,000 cubic metres.-^ They are enclosed Li3wer Flysch Btrrias Layers Fig. 128. — Section across the Habkernthal. in the Flysch, and must therefore have been transported in Eocene times. No granite of this character is at present known in the Alps. (See p. 302.) Along the north of the Lake of Brienz is a range of hills known as the Harder. At Interlaken they sud- denly cease, but on the other side of the valley, and a little further to the west, is another similar range run- ning in the same direction. These two are geologically similar, and are in fact parts of a once continuous range which has been dislocated and displaced. The strata composing it are inverted; the most ancient being at the top. ' Kaufmann, Beitr. a. Geol. K. d. Schw., L. xxii., pt. i. SIX THE UPPBE AAK 297 But though, no doubt, the Lakes of Brienz and of Thun at one time formed a single lake, they are of a totally different character. The Lake of Brienz occu- pies, as we have seen, a longitudinal valley. On the other hand the Lake of Thun is for the most part a transverse valley of erosion. Fig. 127 gives a section across the Justithal, between St. Beatenberg and Sigriswyl, which, as will be seen, is an anticlinal valley. The lower end of the Lake of Thun is dammed up, at any rate in part, by the deposits of the Simmen and the Kander. There is a curious point connected with the exit of the river Simmen (Simmenthal) from the mountains near Simmis. Instead of following the low ground between the Stockhorn (Jurassic) and the Niesen (Eocene), it has cut a gorge through the end of the former, detaching the Burgfluh (Jurassic) from the rest of the Stockhorn, of which evidently it formed originally a part. It is probable that this is due to the amount of debris brought down by the HoUengraben and other torrents coming down from the Niesen, which have driven the Simmen to the north of the Buigfluh. CHAPTER XX ZURICH AND GLAKTJS The Lake of Ziirich is about 26 miles long, and 3 in width, is 142 metres in depth, and 409 above the sea. The immediate scenery, though not grand, is soft and rich, with a great air of comfort and civilisation. Fig. 129. — View across the Valley of Ziiricli. The whole valley was excavated by water in pre- glacial times, and subsequently occupied by the glacier. As we look up the lake from Ziirich we see in front the fine range of snow mountains from the Glarnisch to the Windgalle and Titlis. The valley on the left is bounded by a ridge of Mollasse — the Ziirichberg. On the right are two ridges. The nearer and lower one is the lateral moraine of the glacier during the last Ice age ; the upper ridge is the Albis, 1500 feet in height, and consisting of Mollasse and corresponding to the Ziirichberg. The very summit of the Albis is also capped by glacial deposits, and the glacier extended at one time as far as Waldshut. The hotel on the summit 298 CHAP. XX ZiJKICH AND GLAEUS 299 of the Uetliberg stands partly on MoUasse, partly on the Moraine. After a long period the climate improved, the glacier retreated, and the melting ice caused torrents which cut into and redistributed much of the material brought down by the old glacier, forming great fluvio-glacial deposits, more or less cemented together, and (see ante, p. 101) known as " Deckenschotter." Immediately under the restaurant at the summit of the Uetliberg is a considerable thickness of this deposit, forming per- pendicular cliffs, under which are remains of ground moraine. The "deckenschotter" being pervious, and the ground moraine impervious, to water, springs occur at the junction of the two. The glacier during the Second Ice age also extended to Waldshut. It does not appear, however, to have stood very long at its extreme limit. The terminal moraine is unknown. To this period, however, belong the side moraines at Zugerberg, Hohe Ronen, Gubel, on the top of the Albis range, Hasenberg, Ziirichberg, etc. The moraines of the last Ice age are, as might natu- rally be expected, more clearly marked, and have greatly determined the scenery of the district. I'he lateral moraine, as already mentioned, forms the low range of hills on the west of the lake, and separates it from the Sihl. The outermost terminal moraine of the last Ice age is perhaps that at Killwangen, below which is a mass of fluvio-glacial deposit, forming the so-called Wettingerfeld. The next terminal moraine is just below Schlieren. Then comes the great moraine of Ziirich; its highest points are the Muggenbiihl, the hill of the Botanic Gar- den, the Lindenhof, the quarter known as Winkelwies, and the Hohe Promenade. Outside of the moraine is a 300 SCENERY OF SWITZERLAND chap. great stratified mass of glacial deposits, and the whole forms a ridge which constitutes the lower lip of the Lake of Ziirich. The river has cut through the ridge to a depth of 11 metres ; the lake must therefore have formerly stood at that height above its present level, and joined the Lake of Walen, from which it is only separated by a flat plain. The glacier during its retreat made another long halt at Wadenschwyl and Rapperschwyl, forming moraines, the latter of which reaches almost to the water level, and has been utilised for the railway. It bears a num- ber of erratic blocks, some, and indeed when the water is low many, of which project above the water level. The Lake of Ziirich then is a drowned river valley dammed by a moraine. The valley of the Linth, as the Upper Limmat is called, is a cross valley, the upper lake from Utznach to Richterswyl is longitudinal, the upper portion of the lower lake crosses the strata somewhat diagonally, while the rest of the lake and the Lower Limmat is again a cross valley. On both sides of the Lake of Ziirich are a series of terraces, the upper ones reaching to a considerable height. Th^y are especially conspicuous from Meilen to Stafa, and at Horgen. The valley itself, like the others which cross the Swiss low country, no doubt commenced in preglacial times. During, if not before, the first interglacial period it was excavated to its full depth, i.e. consider- ably below the present level, and partly refilled during the Second Glacial period. In preparing the founda- tion for the quay bridge at Ziirich, the glacial deposits were pierced to a depth ol: 40 metres without reaching the bottom of the valley, and they are estimated at a thickness of over 100 metres.^ > Uu Pasquier, Beitr. n. Gool. K. d. Scliw., L. xxxi. XX ZiJEICH AND GLARUS 301 Indeed, unless there is some cross ridge of which we have no evidence, it follows that as the lake has a depth of 142 metres, we may, even without allowing for any slope of the valley, assume that the dam of glacial matter must have as great a height, or, adding the 11 metres, no less than 675 feet. I have throughout spoken of this valley as that of the Limmat. As a matter of fact, however, it was at one time occupied by the Rhine, and perhaps originally be- longed to the Sihl ; the Linth or Upper Limmat then flowed through what is now known as the Glatthal, until the great Rhine glacier, pressing westwards, drove it unto the then valley of the Sihl, and subsequently retreating left the Glatthal a deserted valley, only trav- ersed by the little stream of the Glatt. The Sihl With the history of the Lake of Ziirich, that of the river Sihl is closely connected. Its course is curious, and its history very interesting. Rising in the mountains of Schwyz it makes straight for the Lake of Ziirich. At Schindellegi it is only 3 km. (less than 2 miles) from the lake, and no less than 350 metres, or 1150 feet above it. Here, however, the mo- raine opposes a barrier which the river has found insu- perable, though it only rises to about 12 metres above the level of the stream, and the consequence was that the Sihl was diverted from its natural course. The Upper Sililthal, above Schindellegi, is a broad flat valley. The moraine of the Linth glacier, however, pushed the Sihl to the west and finally excluded it from its own valley. It flowed by Sihlbriick, and Baar, where a broad valley, now dry, leads towards the Lake of Zug. This was the second course of the Silil. Its adventures. 302 SCENERY OP SWITZERLAND chap. however, were not concluded. During the Third Ice age the glacier of the Reuss occupied the Lake of Zug and gradually built up a moraine from Menzingen, east of Sihlbriick, to Mettmenstetten and on to the north. That this moraine belonged to the glacier of the Reuss is proved by pebbles of Eurite from the Madera- nerthal, pieces of porphyry from the Windgalle, and of Gotthard granite.^ The river thus dammed back, took the only course open to it, viz. its present bed between the Albis range and the great moraine' on the west of the Lake of Zii- rich. The present — third — course of the Sihl, there- fore, only dates back to the close of the glacial period. It is remarkable that similar conditions, though not so well marked, occur with reference to several of the other Swiss Lakes : thus the Kander has been dammed back from the Lake of Thun, and the Arve from the Lake of Geneva. The Walbn See The Lake of Walen, or Walenstadt, offers a great contrast to that of Ziirich. It is about 10 miles long, 1^ in breadth, 423 metres above the sea, and 151 in depth. The scenery is grand and stern. The south side slopes steeply, and the north is almost perpendic- ular, the cliffs rising to a height of nearly 3000 feet. As will be seen by Fig. 130, the strata are folded on themselves. Beyond them are extensive pastures, which rise to the edge of the cliff. The figure shows the re- markable contortions to which the strata have been subjected. The district on the south, between the lake and the Rhine valley, has also been the seat of tremendous changes. 1 Aeppli, Beitr. £. Geol. K. d. Scliw., L. xxxiv. ZURTCH AND GLARUS 303 The Glarus Mountains The district of Glarus is indeed one of the most inter- esting in the whole of Switzerland. If we ascend the mountains on the south of the Walen See we find every- where the Verrucano as the basal rock, on it lie Rothi- dolomite, Lias, Brown Jura, Malm, Cretaceous strata, and Eocene, — all, whenever present, in their regular order. But farther to the south all this is changed, and the strata ai'e actually inverted. The newest rock. Eocene, is the lowest, and on it lie successively the Cretaceous, Malm, Brown Jura, Lias, Rothidolomite, and Verrucano, which caps several of the mountain summits. This inversion of the strata covers a space of over 1130 square km., and has long been a great puzzle to geolo- gists. Escher, who studied the district with great care, came to the conclusion that the facts could, only be explained by a great fold, turned over as it were so as to invert all the rocks. A similar inversion takes place on the south-east, so that there is a great double fold, starting from the Walen See on the north, and the Rhine valley, — say from Waldhaus Flims to near Chur on the south. The facts seemed so incredible that Escher hesitated to publish it. He told Heim that if he did, no one would believe it. The subsequent researches of Heim, which he has published in his two great works, the Me.chanismus der Gebirgsbildung, and the twenty- fifth vol. of the Swiss Beitrdge, seem to place it beyond a doubt. The arrangement will be rendered clearer by the fol- lowing section from the Walen See to the valley of the Rhine at Waldhaus Flims, a little above Chur, which is given in Fig. 130. On Butzistockli, a fairly accessible point to the west 304 SCENERY OF SWITZERLAND of the Karpfstock and east of the Linththal, Prof. Heim ^ shows that there is a complete series from Malm to Ver- rucano (Carboniferous), but in reversed order, the older rocks lying over the younger, and being reduced to about a tenth of their original thickness. The inverted Verrucano caps several isolated, or almost isolated, summits, viz. the Hausstock, the Riichi, Giflmen Icistkamm TTalenseB SexemOT VeissmeJTett Hageren I Spitzmeilen Fig. 130. — Section from the Waleu See to the Valley of the Rhine at Wald- haus Fliins, a, little above Chur. M, Miocene : E, Eocene ; C, Creta- ceous ; J, Jurassic ; D, Dogger ; R, Rauchwacke ; V, Verrucano. and the Graue Horner on the north, — the Piz Dartgas, Surrhein, Vorab, Laxerstockli, Piz Segnes, Ringelspitz, etc., on the south, and occupies a considerable district between the Linththal on the west and the Sernfthal on the east, in all these cases actually overlying the later rocks. If this explanation be correct, the Verrucano which caps the mountains as shown in Fig. 130 must be con- 1 Heim, Livret Guide. ZURICH AND GLAEtrS 305 tinued below. That this is so is proved by the section shown in the Tamina-thal at Vattis (Fig. 132), where the vallpy is actually cut down to the Verrucano. In the eastern district of the fold we find a similar case in the deep valley of Liminerntobel. Heim considers the views from the summits of the Hausstock, Ringel- kopf, and Graue Horner as among the grandest in the whole Alps. That the Jurassic strata once extended far beyond their present limits is shown by Fig. 133, giving a sec- Sardoncb Kala'biEii'kopf Schcibo ■ Magerea Spitzmeilen'Veissgaiidstock Hiirten Ruche Raminerfurkel P.Segnca ; j Weiss-! Schdnbiihl • FauUst ' ! -r-, imeil^n! „- ! IFonstbckli; , = H-j-Poopassi (. ^'-:^£:::<--^^^rN Flimserstein Vorder-Bhein-Thal Umgcpfend von Vorder-Rheill Scalagrab Fio. 131. — Section across the Vorder-Khine-Tlial from Weissmeilen to Versam. tion across the Stock-Pintga, where the fold has pre- served a small outlier of either Lias or Brown Jura. The sections (Figs. 131 to 136) really enable one to form a clearer conception of the country than even a long description, and give a general idea of this inter- esting district. The root, so to say, of the north fold extends from Fluelen by the Linththal to near Glarus, and thence towards Sargans : and the southern border of the north- 306 SCENERY OF SWITZERLAND ern fold runs in a slightly curved line say from the Todi, by Elm, and the Foopass, south of the Graue Horner, and across the Tamina to the Rhine valley some dis- tance below Chur. The root of the south fold on the west appears first at Panix, and follows approximately the valley of the Rhine from near Truns to Chur, concealed, however, by immense deposits of gravel, etc. Beyond Chur it can- 132. — Section across the Tamina Tlial from Mels to Chur. not be traced. The north border of the south fold lies somewhat south of the south border of the north fold. The fronts, so to say, of the two folds approach nearest at the Hausstock on the north, and the Kalkhorn on the south ; and again (Fig. 131) at the Foostock from the north to the Piz Segnes on the south. The formation of the two folds was probably contem- poraneous, though Heim considers that the south fold probably commenced first. XX ZURICH AND GLARXJS 307 The effect of the double fold has been to shorten the distance between the Walen See and the Rhine valley by 32 km., that is to say from 67 km. to 3.5.i Tlie north fold is 90 km. long with a maximum breadth of 16 km., the south fold 48 km. long with a maximum breadth of 13 km. Altogether the strata are reversed over a sur- face of 1130 square km. But though we thus get a general idea of this won- derful and interesting district, there are many questions Fig. 133. —Section of the Stock-Pintga from Val Rusein. d, Brown Jura or Lias ; e, Triassic Dolomite ; /, Carboniferous Strata. still to be cleared up. The commencement of the fold ; to the east and west are still obscure, and the strata are in many places so crumpled, contorted, crushed, an.l metamorphosed that they can scarcely be recognised. In many places the ridges are very sharp, and in tlu Vorab chain above Elm in the Sernfthal, the steep cal- careous strata form a wall 100 to 150 metres high, but very narrow. At one place the rock has weathered away, leaving an opening 16 metres high and 20 metres broad, known as Martin's Loch. It is so high over Elm that twice in the year, on the 4th and 6th March and the 14th and 15th September, the sun shines through it onto the spire of the village church. But we may ask, why is there this extraordinary 1 Heim, Ilecli. d. Gfebirgsbildunff, vol. i.. 308 SCENERY OF SWITZERLAND chap. amount of folding and contortion in the Glarus dis- trict between the Walen See and the Vorder Rhine? If the general explanation of the structure of the Alps which has been given in previous chapters be correct, it follows that the amount of folding in any section must be approximately equal. Now immediately to the east and west the great Glarus double fold is represented by a number of smaller ones. Further still it is replaced, and the necessary economy of space is obtained by means of the Central Massives. In fact if we look at the map we shall see that in the district of the Alps corresponding to the double fold, from the St. Gotthard on the west to the Silvretta on the east, there is no Central Massif. The Central Massif and the double fold are complementary to, and replace one another.! In fact, in the Massives the central fold turns upward; in the Glarus double fold, down- wards. The district contains two remarkable cases of rock- falls. One belonging to prehistoric times in the valley of the Linth, above Glarus, was from a cornice named Guppen on the east flank of the Glarnisch. The aspect of the valley between Glarus and Schwanden contrasts strikingly with that above and below. It consists of unstratified, more or less angular, debris of calcareous breccia, and the stones show numerous marks of concus- sion. It consists principally of Malm, with a small pro- portion of Dogger, Cretaceous, and Verrucano. It rests on and is covered by glacial deposits, and as in other cases dammed up the valley and formed a lake. The other great rockfall, that of Elm, was the most 1 Eothpletz (Oeotectonische Probleme) has propounded another ex- planation, based on faults and overthrusts. Without wishing to dog- matise on so difficult a problem, the explanation given by Studer and Heim seems to me most in accordance with the facts. ZUEICH AND GLARUS 309 disastrous which has occurred since that of the Rossberg. It took place on the 11th of September, 1881, from the side of the Tschingelberg, at a height of nearly 3000 feet. Over 80 houses were destroyed and 115 persons killed. The place is still a scene of wild desolation. The Glaeni'sch The Glarnisch is another complicated case of foldings.^ It is both orographically and geologically a trough. The strata are folded on one another like an S cut off at the two sides by the valleys of the Linth and the Klon. Baltzer gives the following table showing the sequence of the strata on the eastern Glarnisch. Normal Sequence. Actual Sequence on the Eastern Glarnisch Eocene Urgonian Urgonian Neocomian Valenginian Upper Jura Middle Jura Neocomian Valenginian Neocomian Urgonian Neocomian Lias Trias Valenginian Neocomian Dyas Upper Jura Middle Jura, Lias Upper Jura Middle Jura Dyas Upper Jura Eocene It will be seen, therefore, that the folds, are very com- plex. The Eocene, the most recent formation of all, is at the very base, and the folds have, in some cases, com- pletely squeezed out particular strata. To the east of 1 Baltzer, Der Glarnisch. 310 SCENERY OF SWITZERLAND the Glarnisch is the Silbern, where Heim has found a similar structure, but even more magnificently developed. WiNDGALLE The Windgalle group have been admirably described by Heim. The strata have not only been folded bj-- pressure acting iu a direction nearly north-east, but actually for a distance of IJ to 2 miles thrown back upon themselves (Fig. 134). The Porphyry, though an eruptive rock, is much more ancient, and has taken no Gr.VaigSlt Maderanerthal Purggeli "Weisstoftk Fig. 134. — Section of the Windgalle. Gn, Gneiss; P, Protogine; A, Am- phibolite ; Sc, Crystalline Schists ; C, Carboniferous ; D, Dogger ; M, Malm ; F, Flysch. active part in this remarkable overthrust. It has been perfectly passive, being itself folded with the other strata. The whole region is particularly instructive. At the commencement of the Carboniferous period the older sediments, converted more or less into Crystal- line Schists, contained already intruded masses of Gran- ite, and were thrown into folds, forming a mountain chain. Over these sediments a mass of porphyritic lava was poured from some volcano or volcanoes, the site of which has not yet been discovered ; and this lava was subsequently covered by another series of Carbonifer- XX ZtJKICH AND GLARUS 311 ous deposits. Before the Permian another period of folding occurred, and the folds were partly denuded, during a long period of subsidence, in which no less than 500 metres of calcareous sediment were deposited. The porphyrj'- which now occupies the summit of the Windgalle at a height of 3000 metres was then covered under a great thickness of Jurassic and Eocene strata. Finally came the foldings which have given rise to the present mountains, in which all the strata from the Carboniferous to the Eocene are folded comformably together. CHAPTER XXI THE RHINE In previous chapters I have traced the great fold of Switzerland, not indeed from its commencement, but along the valley of Chamouni, over the Col de Balme, up the Rhone from Martigny to Oberwald, and over the Furka. It then forms the Urserenthal, and passing over the Oberalp, descends the Tavetsch and forms the valley of the Upper Rhine. To the east the direct route to the Rhine valley would be by the Pass da Tiarms, north of the Calmot. The road, however, rises by a series of zigzags and passes to the south. On crossing the watershed the glen of Tavetsch opens out. It has a length of about 5 km., and on the north presents two terraces, one about 60, the other 2 to 3 metres above the river. The valley below terminates in a narrow gorge near the village of Sedrun. Below the gorge is a second broad stretch of valley, that of Dissentis, which itself is again closed by a second gorge below. Under the enormous gravel de- posits of Dissentis are the remains of an ancient forest. The stumps of the trees, which are still upright, have in some places been exposed by denudation. As in the case of the Rhone, so also here, the Swiss maps fail to convey a clear idea of the geological feat- ures, though for this they are not to blame. They naturally gave a separate colour for the Biindnerschists on the south of the river, in which no fossils had been 312 CHAP. XXI THE EHINE 313 found, and the relations of which were consequently- uncertain. Recent researches, however, indicate that these Schists belong to the Jurassic period, and corre- spond with the strata on the left of the river. The Vorder Rhine, which may be considered as the true Upper Rhine, is generally stated to have its source in two small lakes, the Lake de Siarra, and the Lake Toma on the north flank of the Sixmadun. The tribu- taries which the Vorder Rhine receives on the north side are of secondary importance (see p. 138), but on the south it is joined by the Mittel Rhine at Dissentis, the Somvix at Somvix (Summus vicus, the uppermost village), the Valser Rhine or Glenner at Ilanz, the Rabiusa near Versam, the Hinter Rhine at Reiehenau, the Plessur at Chur, the Landquart near Maienfeld, and the 111 near Feldkirch. The Rhine repeats to a certain extent, and for the same reason, the condition of the Aar below Soleure, which also on account of the general slope of the country receives all its important tributaries on the south. Several of these streams are dangerous torrents, and are still rapidly deepening their valleys. For instance the Glenner, which drains the Lugnetz, and falls into the Rhine at Ilanz, is in very active operation. Its valley is a deep notch, almost a gorge. The villages are situated high above the stream on an old river ter- race, which in the lower part of the valley has a height of 1000 metres, and at Oberlugnetz of about 1500, above the water.i None of the lateral streams are able to form cones, all the material they bring down being swept away by the Glenner. Under the village of Riem the whole slope is in a most insecure condition ; the houses are continually cracking and giving way, and have to be supported and restored. 1 Heim, Beitr. z. Geol. IC. d. Schw., L. xxiv. 814 SCENEEY OP SWITZERLAND chap. The drainage area of the Upper Rhine was formerly larger than it is at present. The Italian rivers having a steeper course, have here, as elsewhere (for instance, in the Engadine (see p. 352), and indeed we may say along the ridge of the Alps generally), eaten their way northwards, invaded the Swiss valleys and carried off to the south certain streams which were originally tribu- taries of the northern rivers. The Scaradi-a, for in- stance, to judge from its upper river terraces, formerly ran by Motterasco and Greina, into the Val Somvix, and so to the Rhine at Surrhein. The Carassina again, which now makes a sharp turn and flows into the Brenno near Olivone, ran north into the Val Camadra and by the Greina Pass to Val Somvix. This sugges- tion may seem at first improbable, but river terraces can be traced to a height of 2200 to 2400 metres. The upper part of the Rhine^ as far as Dissentis pre- sents many gravel terraces, which probably belong to the period when the river was dammed by the great rockfall of Flims. They are not mere river cones, but regularly arranged terraces, with a steep fall to- wards the main liver. They carry us back to a time when the masses of debris which fell from the sides, or were brought down by the lateral streams, were sub- jected to a process of regular rearrangement, and they attain such dimensions that the villages all stand on this terrace. The present state of things is very differ- ent, erosion prevails over deposition, the lateral streams have cut, and every year are cutting more deeply into the terrace, and the Rhine itself is undermining it, so that the houses have in many places had to be set back. The formation of these masses of debris, their arrange- ment in a regular terrace, and the present period of ' Rutimciyer, Eiszeit und Pleiocene axif beiden Seiten der Alpen. THE KHINE 315 removal, represent three different phases in the history of the river. Tliough the general line of the river was probably determined by the great longitudinal fold of Switzer- land, the exact course has been affected by various cir- cumstances. It must be remembered that the river originally ran at a great height, at least 2000 metres, above its present level, and it is therefore by no means easy to ascertain what determined the exact line. More- over, the strata not being horizontal, the centre of the present probably diverges more or less from that of the original valley. The following figures will, I think, give a better idea of the structure of the Upper Rhine Valley than even a long description. Fig. 135. — Section across the Rhine Valley at Dissentis. Fig. 135 gives' a section across the valley at Dis- sentis. The river runs on a deep bed of recent deposits, resting on steeply inclined crystalline rocks. At Somvix the structure is similar. The next figure (Fig. 136) gives a section at Truns and shows the structure of the Bifertenstock and the Brigelserhorner. From Truns to Ilanz the valley is excavated in Ver- rucano, which forms the root of the south wing of the great Glarner double fold (see ante, p. 303). Above 316 SCENERY OF SWITZERLAND chap. Ilanz and below Chur the Verrucano is in its natural position, but between the two it is folded on itself. Fig. 137 gives a part of the double fold on the Sardona and the great rockfall at Flims. From Ilanz to Chur the river corresponds, not to a synclinal, but to an anticlinal zone ; and if we consider its present position only it is difficult to understand the line it has taken. We must, however, endeavour to carry back our imagination to a time when it ran at a level say 2500 to 3000 metres higher. If we realise this and replace the strata which have been washed Fig. 136. — Section across the Valley of the Rhine at Truns. away, we should (see ante, p. 307) find ourselves in the fold at the base of the south wing of the Glarner double fold. This trough determined the original direction of the river, which has cut down to the present anticlinal arch. Originally it occupied a synclinal valley, but its present condition is entirely the work of erosion. Waldhaus-Flims stands far above the river, in beauti- ful woods, on the site of the greatest rockfall in Switzer- land, the date of which is uncertain. The fall came from the Flimserstein, and the mass is no less than 700 metres in thickness. The Rhine has cut deeply into, THE RHINE 317 but not yet througb it. As usual with rockfalls the surface is very uneven, and contains several lovely little lakes. At Reichenau and Bonaduz the old river terraces are specially well marked. The remarkable changes which appear to have taken place in the river-system of this region have been already alluded to (ante, pp. 144-145). Symonds regarded the valley of the Averser Rhine as the finest example of high river scenery known to SiiImBn leistomm "TOenseB Sflxemor "¥elssmeileTi llagerea I Spitzaieilm Torab Poopass Sardona TrinserJi. foDstock Torder-Jlhcin-Thal D I' C Fig. 137. — Section from the Waleu See to the Rhine Valley at Films. him. " Without," he says, " going into details of de- scription I will say that I have never seen anything in the way of high river scenerj"- to equal this. The Averser Rhine beats the Sesia and the Mastalone hol- low, and has long odds against the streams of the Dolomites, which I have always thought enchanting. It has a tremendous volume of the purest azure water, ivhich sometimes hides itself in cembratufted gorges, 318 SCENERY OF SWITZERLAND chap. sometimes swims through grassy meadows with wide swirling curves that hollow out the turfy margia to their liking, sometimes carves a narrow monumental way through solid marble pure as Parian or Pentelican, sometimes falls thundering in cataracts encircled with a dozen changeful rainbows, sometimes glides deep and solemn in dark pools, which make one dream of death and long to dive in them and find the mystery." ^ Below Reichenau are several remarkable hummocks in the valley, known as the Rosshiigel, the origin of which has been much discussed. Heim regards them as the remains of a great rockfall. The valley here is occupied by gravel, etc., of un- known depth. The conspicuous band in the cliff on the left side of the valley below Chur is Neocomian. The upper part of Chur is built on the great cone of the Plessur. The Prattigau, which lies on the east side of the river from Chur to Maienfeld, is considered to be an area of subsidence. Ragatz is celebrated for its hot springs and the gloomy gorge of the Tamina. The valley of the Rhine at Sargans below Chur di- vides into two branches. At one time the river appears to have followed that on the left, and passing through the Lakes of Walen and Ziirich to have occupied what is now the course of the Limmat and rejoined its present course at Waldshut. At present, however, it takes the right branch and so joins the Lake of Constance at Bregenz. The ancient glacier of the Rhine extended beyond the Lake of Constance and even invaded the valley of the Danube. Here, as in the case of the Rhone, it is very interest- ing to see how the moraines retain their respective posi- 1 Symonds's Biography, vol. ii. XXI THE RHINE 319 tions to the end. There are some characteristic rocks which are of very local origin. Guyot mentions ^ espe- cially (1) the Porphyritic Granite of the Puntaiglas district, (2) the Green Granite of the Julier Mountains, (3) the Brown Gneiss of the valley of Montafun. The Puntaiglas Granite keeps always to the west. One belt passes down the valley of the Lake of Walen, the other continues along the left bank of the Rhine valley to and beyond Winterthur. The Green Julier Granite occupies the centre. It comes from the mountains over the Upper Engadine, down the Oberhalbstein Rhine and the Albula, is scat- tered over the Canton of Thurgau along the west of the Lake of Constance and far away to the north and east. The Brown Gneiss of Montafun lies to the east. It comes down the valley of the 111 to the Rhine at Feld- kirch, extends to the east of the Lake of Constance, and is abundant at Lindau, reaching far beyond Ravensburg. Thus the Puntaiglas Granite is found only on the west, the Julier Granite in the centre, and the Brown Montafun Gneiss on the east. The Lake of Constance is 400 metres above the sea and 276 metres in depth, it is 40 miles long and covers 208 square miles. At its west end it is dammed up to a certain height by the deposits of the ancient Rhine glacier. This, however, would not account for more than say a quarter of its depth. It is therefore a rock basin, and is, in Prof. Penck's opinion, as he has been good enough to inform me in a letter, due to changes in relative levels, or to excava- tion by the glacier. 1 Giiyot, " Sur la distribution des espSces de roches dans le basin du Rhone," Bull. Soc. JSTeuchatel, vol. 1. 320 SCENERY OF SWITZERLAND chap. Volcanic District of Hohgau Volcanic phenomena play a very subordinate part in the physical geography of Switzerland. No doubt the masses of Granite, Porphyry, Syenite, Gabbro, Diorite, etc., sufficiently indicate the existence of plutonic forces, but the enormous denudation which has taken place has long ago removed all the surface rocks, leaving only " necks " or volcanic chimneys like those found in Scot- land and elsewhere. The district of Hohgau, north-east of Schaffhausen, is however an exception. Here there is a group of com- paratively modern, but extinct volcanoes (Fig. 138). Fig. 138. — Volcanic Group of the Hohgau. Seen from the North-west. Some are basaltic — Reidheim, Hohenstoffeln, Hohen- howen ; others are phonolithic — • Hohentwiel, Magde- berg, and Hohenkrahen. They appear to have been Miocene, as phonolitic tufs, probably derived from them, are interstratified with the freshwater deposits of Oen- ingen. The hills rise to a height of 850 metres, steeply on the east and north-east. The tufa contains angular fragments of Jurassic rock, but no trace of any poster- tiary deposits. They are therefore Postjurassic ; but although we find basaltic bombs, lava tears, ashes, etc., looking so fresh that one might suppose them to belong to an existing volcano, it is evident that the period of activity had already ceased before the glacial period. XXI THE BHINB 321 Below the Lake of Constance the Rhine ran no doubt nearly in its present course even before the glacial period, but not exactly. At one time it seems to have occupied the broad and now deserted valley of Klettgau. The present course has many marks of being comparatively recent. Hence the bars of rock, one of which causes the cele- brated and magnificent fall at Schaffhausen. This ridge regulates the height of the Lake of Constance, which would have been much lower if the Rhine had been run- ning in its former bed. The play and change of colour at the falls is wonderful. In the early morning, as I have seen it from the Neu- hausen side, the river above the falls looked like a smooth, undulating table of rock, from the ledge of which, the water suddenly seemed to leap, as if the rock were struck by a Prophet. As the sun rose higher the upper liver became a sheet of living silver, suddenly dashing down the falls like an avalanche, shot with green or springing up into the air in a shower of spar- kling diamonds, tinged here and there with pink. By midday the upper reach of the river was deep violet,, the lower water blue, gleams with green, and the white foam carried down into the depths showed much more distinctly, seeming to swim about in the blue like water spirits spreading out white arms. Li the afternoon the water above became almost black, that below green with scarcely any blue. Towards sun- set it appeared again bluer, and the upper water lost much of its colour. In the fall itself there was less change from hour to hour. It was brilliantly white, and the water seemed to spring from rock to rock with restless glee. Towards evening, however, greenish tints appeared here and there. 322 SCENERY OF SWITZERLAND chap, xxi At present the Rhine-falls appear to be undergoing little change. The oldest drawings and descriptions give very nearly the present details. This is mainly due to the absence of sand and gravel. The main work of the Rhine now is, — accumulation between Chur and the lake ; from the lake to the entrance of the Thur little change is taking place ; and thence to Basle a slow cutting away and widening of the bed. The celebrated quarries of Oeningen at the west end of the Untersee are in freshwater calcareous strata re- posing on the MoUasse. Heer has described no less than 50 species of Vertebrates, 826 insects, and 475 plants from these deposits. The valley of the Rhine below Basle, as far as May- ence, is a band of subsidence as explained in the chap- ter on the Jura (see p. 193). The calm and yet rapid rush of the river at Basle is very impressive, carrying the freshness, and the cool clear waters of the mountains to animate and purify the plains of Germany ;uid Holland. CHAPTER XXII THE KEUSS In previous chapters we have rapidly traced the great longitudinal valley of Switzerland from Chamouni to the confines of Germany. We will now in the same way consider the two great transverse valleys of the Reuss and the Ticino, which cross the Rhone-Rhine Valley more or less at a right angle, thus dividing Switzerland into four approximately equal parts. The remarkable evidence of glacial action presented by the Lower Reuss has been referred to in the chapter on Glacial Phenomena (^ante, p. 84), the probable origin of the Lake of Lucerne has been alluded to in the chap- ter on Swiss Lakes (^ante, p. 163), and the surrounding mountains in that on the Outer- Alps {ante, p. 214.) The Lake of Lucerne is 437 metres above the sea and is 223 metres in depth. From an ancient delta of the Muotta, and remains of terraces, it would appear ^ that the water once stood some 30 metres above its present level. It would then have formed one sheet with the Lake of Zug. The lake itself, as its form clearly indicates, is no simple phenomenon, even like that of Ziirich for in- stance, but is very complex. The surrounding hills at the western end are formed of MoUasse, thrown as iDu Pasquier, Beltr. z. Geol. K. d. Schw., L. Xixi. 323 324 SCENEKY OF SWITZEELA^'D already mentioned into two main arches running S.E. to N.W. The intermediate trough, or synclinal line (Fig. 139), between them, passes by Krienz, south of Lucerne, crossing nearly the middle of the bay, near Kiissnach, across the Lake of Zug from Immensee to Walchwyl, thence to Egeri, and across the Lake of Egeri to Schindellegi. Both the MoUasse arches have their summits razed. The Rigi and Rossberg represent the south wing of the south arch, and dip towards the lake. For the relation of the Rigi to the Vitznauerstock see ante, p. 219. If we look at the map we shall see that the Reuss J^^gij Crlaciairv ~ Mbllasse dktuc douce ■j TotLcUn^ues 2:fj MbUasse T7i/zrino ^^^gg Eocene [^]_;lJJ V'rffonien, Fig. 139. — Section through the Rigi and Vitznauerstock. makes a considerable detour by Lucerne. The natural course would be by Schwyz, through the Lake of Lo- werz, and the Lake of Zug, rejoining its present course by the valley of the Lorze. A slight I'elative elevation of the country round the Lake of Zug, or rather a de- pression further south, probably gave rise to the change, forcing the Reuss to alter its direction, and overflow at Lucerne. As already [)ointed out the old river terraces of the THE REUSS 325 Reuss can still be traced in places below Zug, and (see p. 163) slope the reverse way to the valley. From this and other evidence we conclude that there has been a relative elevation of the land, Avhich has dammed up the valley, thus turned parts of the Aa and the Reuss into lakes — the two branches of the Lake of Lucerne known as the Alpnach See and Urner See, The Bays of Alpnach and Kiissnach are in fact a continuation of the valley of the Sai-nen Aa, which forms the Lake of Sarnen. The Bay of Alpnach lies in a synclinal valley between two cretaceous ridges which unite further west to form the Blirgenberg. Several of the smaller bays, Bochfiuk Satterlipass Schcidciio'Dossen Mgl lulm '^neboaenr '''■VT. A'.E. Fig. 140. — Slope of the Rigi from the North. as for instance those of Langensand and Winkel, are due to the existence of comparatively soft and destructi- ble strata. The Bay of Uri is a transverse valley, part of the course of the Reuss. The Buochs-Brunnen-stretch is a trough, — perhaps the old course of the Engelberger Aa, when it joined the ancient Reuss at Brunnen and continued with it by Schwyz and Zug; the portion near Brunnen is, more- over, in a synclinal. The Waggis-Vitznau basin on the contrary is a " combe." The MoUasse (Nagelflue) of the Rigi slopes to it on the north, and on the south it is bounded by the fractured arch of the Biirgenberg. The Bay of Lucerne is excavated in MoUasse and is probably the most recent portion of the lake.^ 1 Rutimeyer, Der Bigi. 326 SCENERY OP SWITZERLAND chap, xxii The Lake of Zug has somewhat the form of an hour- glass, owing to a bed of hard puddingstoue which crosses it obliquely to the north of Immensee. The railway from Lucerne to Brunnen passes the scene of the remarkable rockfall of Goldau. The line passes between immense masses of puddingstone, and the scar on the Rossberg from Avhich they fell is well seen on the left. The mountain consists of hard beds of sandstone and conglomerate, sloping towards the valley, and resting on soft argillaceous layers. During the wet season of 1806 those became soaked with water, and being thus loosened, thousands of tons of the solid upper layers suddenly slipped down and swept across the valley, covering a square mile of fertile ground to a depth, it is estimated, in some places of 200 feet. The residents in the neighbourhood heard loud cracking and grating sounds, and suddenly, about 2 o'clock in the afternoon, the valley seemed shrouded in a cloud of dust, and when this cleared away the whole aspect of the place was changed. The valley was blocked up by immense masses of rocks and rubbish, Goldau and three other villages were buried beneath the debris, and part of the Lake of Lowerz was filled up. More than 450 people were killed. The Bay of Uei The Bay of Uri used to be regarded as a typical valley of fracture. The bottom is, however, nearly horizontal, and it is evidently a river valley due to erosion. The two sides (Fig. 141) are reflections one of the other, though, as the lake runs nearly north and south while the strike of the strata is south-west by north- east, the corresponding portions of the strata on the west side lie somewhat further south than those on the east. Fig. 141. —The Bay of Uri. 328 SCENERY OF SWITZEKLAND chap. Between Kindlimord and Schwybbogen a moraine covers the bottom of the lake, and rises within 50 metres of the surface.^ The walls of the Bay of Uri are formed mainly of Cretaceous strata lying on Jurassic (Malm, Dogger, and Lias), and thrown into various folds and arches. As we approach Bruniien from the west, a magnificent arch of Neocomian capped (Fig. 141) by Urgonian (on which the hotels of Axenstein and Axenfels stand) may be seen at the commencement of the Axenroad, and on looking back from Brunnen the counterpart can be traced under Seelisberg. The strata are folded back upon themselves, over the summit of the Frohnalp (Fig. 141), and down again in a deep trough at Sissikon, where the Cretaceous and Eocene strata aie perpendic- ular. This great fold shows itself near Bauen on the opposite side of the lake, and the depression continues to the west up the Isenthal, and to Altzellen, south of Stanz, and eastwards by Riemenstalden across the Muot- tathal and up the Starzlen brook. The strata exposed at Sissikon by no means form the bottom of the fold. It continues much deeper, and then, according to Heim, turns up and reappears just beyond the Tell Chapel, and at the opposite side at Isleten, where Eocene strata again occur. Such a contortion is almost inconceivable, but the marvellous foldings of the Neocomian strata, which we can see for ourselves, a little further along the road towards Stutzegg just before reaching Fluelen, are enough to convince us that it is not impossible, and Prof. Heim has certainly brought forward strong evi- dence in favour of his view. The two " Mythen," which form a grand feature as we look up the Muotta Valley from Brunnen, consist of 1 Heim, Beitr. z. Geol. IC J. Schio., L. xxv. sxii THE EEXTSS 329 Jurassic and Triassic strata resting on Eocene. Their structure has given rise to much discussion. The Buochserhorn and the Stanzerhorn present a similar arrangement, and the probable explanation has been given in chapter xiii (see p. 223). Valley of the Upper Retjss For some distance above Fluelen the valley is occu- pied by deposits of the Reuss. The living rock first appears at Amsteg, from which village to Attinghausen the road passes through a Flysch region of rich meadows and shady woods ; from Attinghausen to the Bock brook, about half an hour from Erstfeld, is Hochgebirgskalk. The valley above Fluelen has been admirably described by Riitimeyer, from whose memoir ^ most of the follow- ing details are taken. The Upper Reuss is a transverse valley, and in fact from Erstfeld to Luino on the Lago Maggiore, the strike and mineral character of the rocks on both sides of the valley are very similar. The two sides indeed are so similar that in several cases lines of fracture can be traced completely across the valley. At Erstfeld the crystalline rock appears, mainly Mica schist, and micaceous Gneiss. As we look westwards — the jq.gged ridges of the crystalline rocks are in marked contrast to the softer outlines of the calcareous mountains. From Amsteg to Gurtnellen the prevalent rock is Sericitic Gneiss, with lenticular masses of Araphibolite, which stretches away south-westwards by Guttannen to the Lauteraarhorner and eastwards to the Tschingel Glacier. 1 Uber Thai- u. Seebildimg. 330 SCENERY OP SWITZEELAND chap. At Gurtnellen we come to Protogine, over which the Reuss flows nearly as far as the Devil's Bridge. At Inschi, a little way above Amsteg, a reef of hard Gneiss crosses the valley obliquely. The lieuss is still engaged in cutting through this barrier. Its upper edge is covered by debris and vegetation, but the gorge of the river is 200 to 300 feet deep, with vertical walls. It will be evident to any one that this narrow gorge has been cut by the foaming water. Above it is the imposing summit of the Bristenstock with a regular Fig. 142. — Section ol Reuss Valley near Amsteg. i slope of over 2000 metres in height, except where it is indented by a river terrace, which will be again men- tioned further on. As we ascend the valley we meet other Gneiss ridges, in some places at fairly regular intervals of 1000 feet, evidently recurrent layers of specially hard rock. In proof of this it may be observed that each ridge has a weather and a lee side. The weather or upper side is sloping, ground and polished by the action of ice and water, while the side towards the valley has been left steep and rough. ' Uber Thai- u. Seebildung. xxn THE EEUSS 331 Between two of these reefs the Fellibach falls into the Reuss. The valley of the Reuss is here at a height of 713 metres. A very steep path leads up to the houses of Felliberg, beyond which the inclination becomes much gentler. The hamlet stands on a ridge at a height of 1543 metres, corresponding to the terrace above men- tioned, which from this point of view can be clearly traced on the mountain sides both up and down the main valley. At the projections it generally bears the last winter dwellings (Arniberg, etc.). To it also cor- respond the other side glens, which, with the exception of the Giischenenthal, the reason for which we shall see presently, like the Fellithal, after a comparatively gentle is Fig. 143. — Eeefs in the Valley of the Reuss. slope, drop rapidly into the main valley, so that from the Reuss the steep entrances are alone visible. The same difference of level between the main and the lateral val- leys occurs in the Aar and other similar valleys. The steep inclines become shorter as we ascend the Reuss, and from a favourable point of view it can be seen that their summits form a common terrace with an inclination less steep than that of the Reuss, so that if we look down the valley it becomes gradually higher and higher above the present river ; while, on the other hand, if we look up the valley they converge, finally meeting at Ander- matt. This " terrace " therefore commences at Andermatt ; 332 SCENERY OP SWITZERLAND chap. it can be traced along the main valley, as a line or ridge on the steep side, and descending gradually, though not so rapidly as the floor of the valley itself, but attaining much greater dimensions in the side glens. It is obvious that this terrace represents a former " thalweg " of the Reuss with much less fall than it has now, and that the river has deepened its valley more rapidly than the lateral streams, so that these glens open at some distance up the side of the valley, and their waters join the Reuss by rapids or waterfalls. The bridge at Pfaffensprung below Wasen leads again across a vertical gorge over 100 feet in depth. Here the Meien Reuss reaches the valley in a deep cutting from the high-lying Meienthal. The Granite — or, as it is marked on the map, Granite Gneiss of the Upper Reuss — is vertically cleft in two directions approximately at right angles to one another, and is divided, moreover, into horizontal layers at toler- ably regular intervals of 3 to 6 feet. This structure gives it a tendency — also present, though less pro- nounced, in the Gneiss — to break into six-sided blocks. The Gneiss of the Ticino has a similar character.^ It is evident that the valley of the Reuss is a valley of denudation, and the factors which have determined its present configuration are rain and water, ice and frost, the character and structure of the rock, and, lastly, the Reuss itself. The strata strike somewhat obliquely across the valley ; they are nearly vertical, and differ greatly in hardness, forming reefs across the valley. These ridges divide the valley into a number of small basins. They dam back the water, which gradually saws through them, and then with comparative rapid- ity drains the basin above. Riitimeyer represents the 1 Rolle, Beitr. z. Gml. K. d. Sc/ur., L. xxiii. THE REUSS 333 phases of this sequence in the accompanying diagrams, representing sections of the valley which repeat them- selves over and over again. In Fig. 144, I, the river is sawing through the rock. When this is accomplished, the process of widening I II Fig. 144. — Section of the Reuss Valley. begins and debris fall down from the sides (Fig. 144, II). Gradually the valley becomes occupied by debris, through which the river cuts a gorge (Fig. 145, III), III IV Fig. 145. — Section of the Reass Valley. and having done, begins again to saw through the solid rock (Fig. 145, IV). Thus we have a succession of sawing, widening, fill- ing, removal, and then sawing again. Owing to the nearly vertical position of the rocks they present the same character from the highest peaks 334 SCENERY OF SWITZERLAND chap. to the bed of the river, and we are brought irresistibly to the conclusion, however incredible it may at first appear, that the whole valley has been cut out by the river. The Upper Reuss is evidently of great antiquity. It is older than the lateral valleys which drain into it, for it cuts across the ranges of mountains which divide them from one another. It must therefore be anterior to these chains, and we get an inkling how slowly they must have been raised, because the river must have had time to cut down into them during their elevation, so as to maintain its course. The valley shows clear evidence of glacial action. The hard rocks are in places quite polished. This is especially the case with the buttresses which stand like doorposts where the lateral glens open into the main valley, and particularly on the right side of the eastern glens, the left of the western, where of course the press- ure of the ice was greatest. Among the most beauti- fully polished are the left doorposts of the Goschenen- thal, the Meienthal, and above all, the Gornerenthal. The 1500 metre terrace is not, however, the oldest or highest. At a level of 2000 metres there is a terrace even more ancient, but still clearly visible, indeed the one which was first observed, and which was represented by Agassiz long ago in his view of the Bromberghorner. Above it the rock surface shows no trace of glacial action. There is also a third less conspicuous terrace, at a height of about 800 metres, on which Gurtnellen stands, which represents the lowest level to which the ice lias reached. Below it we find evidence of river action only. We have then four "thalwegs," all rising to the south, but with very different inclinations, the steepest XXII THE RETJSS 335 being the present Reuss Valley. They all converge up- wards ; the Gurtnellen terrace joins the present Reuss level at Wyler, the terrace of the side valleys at Ander- matt, the 2000 metre terrace on the shoulders of the St. Gotthard, at Monte Fibbia, and Monte Prosa. These terraces are not of course continuous; in many places they have been washed away ; they have been cut into by lateral torrents, but here and there they appear, sometimes on one side of the valley, sometimes on the other. These conditions indicate successive phases in the history of the valley, periods of comparative quies- cence, between others of more rapid excavation. The two most conspicuous are the present river course and the 1600 metre terrace. The other two represent former limits of ice action, the 2000 metres the highest level to which the glacier attained; the 800 metre terrace the level of the valley when the ice finally retreated. Riitimeyer proceeds to consider the causes which gave rise to the phases of rapid action and relative repose, in which respect he regards the Goschenenthal as particu- larly instructive, and he concludes that the periods of repose represent those of great extension of the glaciers. This explanation may apply to what I would call the two glacial terraces, but not I think to the others. The 1600 metre terrace is probably the level of the valley at a former time when the river had acquired its regimen, and ran for a long period at this level. Then came a subsequent elevation; excavation recommenced, begin- ning at the lower end, and is still in progress ; hence the difference between the slope of the terraces and that of the present valley. The Goschenenthal differs from the other lateral val- leys, as already mentioned, in opening to the Reuss Valley on a level. Now why does this one valley differ in this respect 336 SCENERY OF SWITZEELAND chap. from all the others? The answer is that it is a valley of a different character from the rest. They are due to lateral torrents. The Goschenenthal is a tectonic longi- tudinal valley, which is continued across the Reussthal, on the eastern side forming the Rienthal. Prof. Heim has made an interesting calculation as to the annual denudation in the Reuss Valley. He esti- mates the yearly rainfall in the area drained by that river at 1,070,000,000 cubic metres, and the outflow of the river into the Lake of Lucerne at 750,000,000. The daily discharge of sand he calculates -as about "150,000 cubic metres, to which he adds a quarter for finely di- vided matter. This would be equal tq about 1000 wag- gon loads a day. According to his calculation then the average annual removal from each square kilometre of surface would be 242 cubic metres. From the amount of material removed he calculates the ages of the terraces as follows : — The first or oldest . . . 1,150,000 years. The second .... 330,000 years. The third .... 130,000 years. The fourth .... 23,000 years. From the commencement of the excavation of the valleys to the present there would, he estimates, be required at the present rate of erosion a period of 3,750,000 years.i At Goschenen is the entrance to the railway tunnel, and above it we soon come to the Gorge of SchoUenen, a grand instance of the power of falling water. The road and the river here acquire their greatest inclination. The road winds round a colossal plate of Granite, whose immediate predecessor in nu- "■ Heim, Mec. der. Geb., vol. i. XXII THE KEUSS 337 merous great fragments hangs over the river to the Devil's Bridge, and the Urnerloch is bored through a reef, which once extended across the valley. The gorge is so narrow, that an avalanche might well block it and flood the Urserenthal again, though happily this is unlikely. The 2000 metre terrace is broad here, and intercepts most of the debris which fall from the Batzberg. The Urnerloch is one of the wildest and most striking scenes in Switzerland. Unfortunately of late years it has lost much in human interest, first by the fall of the picturesque arch of the ancient Devil's Bridge, which perhaps was inevitable, and secondly by the construc- tion of great fortifications which sadly mar the grandeur of the scene. Certainly, as Forbes justly observed, " there is nothing more jarring to the impressions of stern grandeur and vast solitude than the not unfrequent occurrence of military works in many parts of the Alps." ^ I am far, however, from blaming the Swiss Government ; the re- sponsibility does not rest with them, but with the great military powers which, if the}'' continue their present policy, will bring Europe to bankruptcy and I'uin. Ueserbnthal On emerging from the Urnerloch we find ourselves on a most interesting spot. Suddenly the whole char- acter of the scenery changes. We leave a narrow, wild, precipitous gorge, with a foaming river, more or less blocked by great masses of Gneiss and Granite fallen from the mountain sides above ; we emerge on a tame, 1 Travels through the Alps. When I was last there the rocks were also desecrated by some monstrous advertisements. It is to be hoped, however, that these are only temporary. 338 SCENEEY OF SAVITZEELAND chap. wide, flat, rather dreary plain, with totally different rocks ; the whole physiognomy of the landscape is entirely different. In fact we find ourselves in a valley of another char- acter, and belonging to a different order of things. We have left a transverse, and find ourselves in a longitudi- nal valley ; we have left a live, and find ourselves in a dead, valley. The Urserenthal is a part of the great longitudinal Rhine-Rhone fold which traverses Switzer- land from east to west, cut off as it were by the Furka from the Rhone, and by the Oberalp from the Rhine. It is geologically a deep trough of Secondary strata (see Fig. 9) forming a fold in the crystalline rocks. The width of the Urserenthal is partly due to the softer character of the sedimentary rocks. Above Andermatt is a small wood, which has been left as a protection from the avalanches. Above the Gallery on the left side of the Reuss, and in the Teufelsthal itself on the right side there is a layer of Sericitic Gneiss about 300 metres thick. The Protogine ceases at the south opening of the Urnerloch, and is fol- lowed by about 500 metres of Chloritic and Sericitic, often Quartzose, vertical Schist, which encloses a pointed trough of Secondary rock (Triassic and Jurassic). The Oberalp road is on Gneiss, but at the third turning is a deposit of black, graphitic shale 65 metres in thickness. Near Hospenthal are several quarries in grayish black Lias containing Belemnites. The Furka Hotel stands on Jurassic strata, which can be traced, with one or two breaks, to Ulrichen in the Rhone Valley. The fold must descend to a great depth, for it was met with and traversed by the tunnel (Fig. 91), which here is 300 metres below the surface.^ 1 Fritscli, Beitr. x. Qeol. K. d. Schio., L. xv, XXII THE KErss 339 From the Urnerloch to Hospenthal the two valleys cross one anotlier diagonally, and at Hospenthal the cross valley leaves the Urserenthal and ascends the St. Gotthard. We leave also the band of sedimentary strata and find ourselves again on crystalline rock. The broad saddle of the pass is seldom entirely free from snow ; it is a wilderness of ice, and snow, and rock, a sort of granite marsh. St. Gotthard The central mass of the St. Gotthard is a more or less elliptic mountain chain, whose ridge and highest sum- mits lie much nearer the south than the north boundary. It is crossed by two long depressions. One begins in the Upper Glienthal, passes by the Wyttenwasser glac- ier to the Lake of Lucendro, from there to the For- tunerthal and the Sella See, the Val Torta, and the Canariathal to the Val Cadlimo. The summit is of Gneiss belonging to the variety known as Fibbia Gneiss. The strata strike parallel to the Urserenthal, and at the summit are vertical. North of the Hospice the Gneiss dips to the south, at the Hospice and on Monte Prosa it is perpendicular, while south of the Hospice the dip is northwards, the south wing being, however, smaller than that to the north. This arrangement therefore gives a typical illustration of the celebrated fan-like structure. The Protogine of the St. Gotthard closely resem- bles both in chemical composition and microscopical structure that of the Aar massif, and they are probably continuous. At and surrounding the Pizzo Rotondo is a mass of Granite, which appears to be intrusive, It is evidently 340 SCENERY OF SWITZEKLAND chap, xxii less ancient than the Gneiss, since it contains angular masses of that rock. From the St. Gotthard radiate six important rivers : the Rhone to the W., the Rhine to the E., the Reuss to the N.E., the Aar to the N.W., the Ticino to the S.E., and the Toce to the S.W., and though the summit does not attain the same wildness or elevation as the heights of some other mountain districts, it presents all the other charms and interest of Alpine scenery, and is espe- cially interesting as the central point of the Swiss Alps. CHAPTER XXIII THE TICINO The valley of the Ticino, or the Val Leventina, cor- responds on the south of the Alps to that of the Reuss on the north. Below Airolo to Bellinzona the river runs, like the Reuss, in a cross valley, it follows in the main the same direction, and like it is cut through crys- talline rocks. It is of similar age, and is a valley of denudation, a child of the same rain and storms. At Airolo it crosses a longitudinal valley, which to the east is known as the Val Piora, and on the west as the Bedrettothal, just as the Reuss crosses the longitu- dinal valley of Urseren, and is joined by the brook from the Oberalp on the east, and the Realp-Reuss from the west. In both cases the stream coming from the west ,is the most considerable. That which drains the Bedret- tothal is generally considered as the Upper Ticino, but the direct continuation of the Leventina is up the stream of the Tremola. Yet though the Val Leventina corresponds in so many respects to tlie Reussthal, in some respects they present great contrasts, and as we cross the pass the scenery changes like magic. The two valleys are, in the words of Riitimeyer, twin brothers indeed, but brought up in a different climate, and clothed in a different dress. The valley of the Ticino, in the boldness of its feat- ures, the grandeur of its dimensions, and the beauty of 341 342 SCENERY OF SWITZERLAND its colouring, has certainly no superior in the whole Alps. From the quantity of snow which falls in the upper valley, -the frequency of avalanches, and the character of the rock, we see here the effects of denudation on a scale which cannot be exceeded, and can hardly be equalled, elsewhere. Below Airolo the valley is divided into successive stages separated from one another by narrow gorges, corresponding to the sections already described in the 1 5 ^ 3 -5 to 5 f^ B a 6 -< ! \ 1- V i < ■J y\ Y i ! -r ^- _ /■ V.j. J Fig. 140. — Section across the valley of the J-icmo. Uu the ieit from Fiesso to Campolungo : on the right from Piotta to P. nera. northern valley : (1) The short piece between Airolo and Stalvedro, which really forms part of the Bedret- tothal, corresponds to the Urserenthal on the north side of the mountains : the gorge at Stalvedro is due to a ridge of Gneiss; (2) the section from Stalvedro to Dazio Grande ; (3) from Monte Piottino to Calonico ; and (4) the broad river valley, which again may be divided into sections from Chironico to Biasca, Biasca to Bellinzona, and Bellinzona to the Lago Maggiore. xxm THE TICINO 343 The river terraces (Fig. 146), or at any rate several of them, are well marked in the Val Leventiua, some- times in small detached pieces, sometimes in larger stretches rendered conspicuous by the white Campanile of the churches in the middle of the Mountain villages. In many places, however, the terraces have disap- peared, and the sides of the valley are so steep that those which remain are far from secure. The valley has been the scene of many catastrophes caused by parts of these terraces slipping down bodily into the valley. The best preserved terrace is that which belongs to the level of the Bedrettothal. It diverges from the present valley level at Madrano, and bears also the villages of Altanca (1392 metres), Ronco (1373), Deg- gio (1214), and Catto (1244). It corresponds with the terrace of Andermatt on the Reuss. In spite of the destructive glacial action it can be traced round Monte Piottino, and below it again forms a broad terrace, visible even on small maps, as bearing the villages of Osco (1164), Mairengo (923), Primadengo (976), Ros- sura (1056), Calonico (987), Cavagnano (1021), and Sobrio (1095). Calonico is celebrated as the seat of the terrible catastrophe of 28th September, 1868. From Altanca to Sobrio this terrace drops 300 metres, while the present river valley falls 900 metres. Here also, therefore, the figures closely correspond with those of the Andermatt terrace in the valley of the Reuss. The terrace, though not so continuous, can also be traced on the right side of the valley, where it supports the hamlet of Nante, and the Alps of Ravina, Prato, etc., as far as Chiron ico. Above this terrace is a yet higher one (Fig. 146), specially well marked to the south of Monte Piottino. It supports no church villages, but some winter dwell- ings, as Ternolgio (1590), Molare (1500), Matengo, etc. 344 SCENERY OF SWITZEELABD chap. Higher still is the upper glacier boundary, which, however, is only visible on some of the highest peaks on the right side of the valley, while the left side soon dips below it. As in the valley of Uri, so here again it is possible also to trace the lower glacier level. It is clearly marked at the opening of the defile of Dazio, and below it is the narrow groove due to the sawing action of the river. At Monte Piottino the sawing has not even now pro- gressed sufficiently far to enable the river to act fully on the part of the valley above. On the other hand the same cause has increased the fall and consequently the erosive power of the water below, and the position of Biasca is in consequence probably somewhat lower than would otherwise have been the case. The same conditions repeat themselves at Chironico, and we may look forward to a time when the lowering of the ridge here will drain the basin of Faido, deepen the cutting at Dazio, and even affect the Bedrettothal. Shortly above Biasca an enormous rockfall took place in 1512. It closed the mouth of the valley of Blegno ; and from the railway the great scar on the mountain is clearly visible. The following profiles giving sections of the valley represent the successive phases in its history; part 11 has passes through stage I, part III through both the preceding. Below Chironico the river ceases to excavate, and is now filling up the valley. Beautiful evidence of its former action, however, still remains in the smooth concave surfaces of rock, 150 feet above the present water level, near the second bridge which carried the old road over the river. ' These can easily be distin- guished from the more completely polished but convex surfaces, characteristic of ice action. They are very THE TICINO 346 well shown at higher levels, and there are few more imposing remains of glacier action than in the Ticino Valley. As in the Reuss the " Doorposts " of the lat- FiG. 147. — Cross Sections of the Valley of the Ticino. I, Bedretto; 11, Piotta ; III., Faido. The dotted line Gl. represents the former glacier ; a is the terrace of Molare (1500 metres) ; and 6 that of Altanca, at Osco (1160) ; c is the beginning of a new terrace ; d is the lower line of the former glacier. eral valleys, as for instance at Osogna, Cresciano, Lod- rino, and Moleno, are highly polished. It is striking to find these clear proofs of ancient glacier action, not only 346 SCENERY OF SWITZERLAND chap. among the Chestnuts of Osogna, but even further down the valley among the vineyards of Bellinzona, and the Cypresses, Olives, and Orange groves of Locarno. And this brings us to another feature which makes a great difference in the general appearance of the valleys of the Reuss and the Ticino. In the former we have dark fir forests, gradually giving place to beech and oats, then mixed with chestnuts and wheat. In the latter we have chestnuts and wheat, then vines on wooden trellises supported by pillars of Gneiss or Granite, passing more and more into the luxuriant veg- etation of the south. This plan gives easy access to the fruit, and the ground is not exhausted as it is wheia the vines are grown on trees. Moreover the Gneiss, though white when freshly fractured, rapidly assumes a rich brown tint and weathers into rounded tower-like forms. The houses also assume more and more the character- istic Italian style of architecture, so different from that of the Swiss chalets. The Canton of Ticino, and indeed the whole district south of the Alps from Domo d'Ossola to Chiavenna, consists mainly of crystalline rocks, generally Gneiss, and more or less steeply inclined, being thrown into a number of folds, which, however, require much further study. The secondary rocks have been almost entirely re- moved by denudation,^ but their former existence can- not be doubted, and remains still exist, though so much metamorphosed as to be hardly recognisable, nipped as it were into some of the deeper folds. They are still, however, notwithstanding the pressure they have under- gone, more destructible than the crystalline rocks, and often give rise to valleys, as for instance the trough 1 RoUe, Beitr. z. Geol. K. d. Schw., L. xxiii. THE TICINO 347 which forms the Val Bedretto and crossing the Ticino the Val Piora; or the Rheinwaldthal at Spliigen.i One of the most important of these folds forms the valley of the Ticino from Locarno to Bellinzona, where it bifurcates, one branch forming the Bregaglia, the other the Lower Val Tellina. At present indeed the Lower Val Tellina seems to be (Fig. 148) an anticlinal valley. But if we carry back our imagination to a time before denudation had pro- ceeded so far, it is evident that the present valley once followed the line of the inclined synclinal of Cino. This is also illustrated by Fig. 57 (ante, p. 183). Fig. 148. — Profile through the Lower Val Tellina to Lola near Novate. One belt of sedimentary strata, now, however, much metamorphosed, can be traced the whole way from Cra- veggia in Piedmont, by Gravedona, to Cercino in the Val Tellina. Some of the smaller lakes in these regions, as for in- stance those of Cadagno and Tremorgia, are " Meres " or lakes of sinking, like those of Cheshire. The massif of Ticino is now cut thi'ough by a series of deep and wide valleys running like the Val Leven- tina from the noi'th, southwards. These valleys owe their origin to the original slope of the ground, and 1 Studer, Qeol. d. Schweiz., vol. i. 348 SCENERY OF SWITZERLAND must be of great age, dating back probably far into the Tertiary period. Several of the Italian Lakes descend below the sea- level. The Lago Maggiore is remarkable for its colossal depth, no less than 655 metres. It is in the main a transverse valley, and at the north and south ends the geological structure of the two sides agrees. The west bank between Arona and Baveno consists mainly of Crystalline Schists, while the east exhibits the whole series of subalpine strata, from the Cretaceous to the Verrucano. The plain of the Po is probably due to subsidence. It is the lower part of the great fold of which the Alps form the upper arch, and must descend far below the sea-level. Fig. 149. — Profile across the Lago Maggiore in Val Verzasca. The alluvial deposits are of great, but unknown depth ; at Milan a boring was sunk for 160 metres with- out reaching the bottom,^ nor do we know on what strata the alluvium rests. The lakes therefore may be compared with the fiords of Norway or of Scotland; they are ancient river valleys, which have sunk far be- low the sea-level. It is probable that the plain of Lombardy was an arm 1 Bonney, Alpine Journal, 1888. THE TICINO 349 of the sea during part of the Ice age, for the manner in which the glacial deposits have been evenly spread over the plain can hardly be accounted for except by marine action. The hill of the Superga, near Turin, is miocene, bent into an anticlinal.^ Fig. 150 gives a section across the Ticino and Ber- nina Massives, from Weissberg in the north, to Dubino in the south. Scegehirge Tesslnor und Benilna Massiv. Liro-Massiv, 1 bO- --^ipPsP -->-., ^— --^ %% ■v GSivimerschie/er}^] Gneiss G:!lisf<^f^ Gneiss ^^''^^VC SSj^^^^^-:3ESjESS5e^ \^,\^ Soiitli Korlli Fig. 150. — Ideal Profile from the Seegebirge across the Tesslner und Bernina Massif to the Liro-Massit. The L. of Lugano owes its complex form to the fact that it consists of two longitudinal, and two transverse valleys dammed up by moraines. It is remarkable that the Lago d'Orta differs from the other Italian lakes in having its outflow, not in the natural line of the drainage, viz. to the south, but on the contrary to the north. This is due to the southern end being closed by a moraine. 1 Penok, Morph. der. Erdoberfldche, vol. ii. CHAPTER XXIV THE ENGADINE The Engadine, or valley of the Inn, from the Maloja, nearly to Kufstein, is a geotectonic valley. The upper portion can be followed down the Val Bregaglia, by Roveredo to Bellinzona, down the Ticino to Locarno, . even beyond which it can be traced far into Piedmont. The Upper Engadine is in the main a district of Gneiss, capped by Crystalline Schists, interrupted here and there by Granite and with troughs of Sedimentary rocks, so much altered, however, by heat and pressure as to be almost unrecognisable, but suggesting that the whole district was once covered by fossiliferous strata. Granite occupies a considerable district between Bevers and Piz d'Err (the Val Bevers being cut into it), both sides of the Julier road from the pass down to Silvaplana, a large tract south of Pontresina, and again the massif of the Monte della Disgracia. The Bernina The Bernina is not a comparatively simple central mass like that of Mont Blanc, where we find a compact crystalline nucleus with well-marked fan-structure. It is rather a complex mass of semi-detached bosses, which were long supposed to consist throughout of crystalline rocks ; but more complete study has shown that these are only a mantle, covering a central mass of plutonic origin, and itself once covered by sedimentary deposits. 350 CHAP. XXIV THE EN6ADINE 351 The so-called fan-structure can be traced, but is not well marked. 1 The Bernina Pass itself has long attracted attention as having no true watershed. The flat summit is occu- pied by four small lakes, at a height of 2220 metres, which in wet weather often unite into a single sheet, from one end of which the water runs north to the Inn, yCraniteZ . Fig. 151. — Section across the Valley of Pontreslna. and consequently to the Black Sea ; from the other to the Poschiavina and the Adriatic. The valley of Pontresina, according to Theobald, is (Fig. 151) a synclinal between two masses of Granite and Syenite. The Inn is a river which has been deprived of its original source. In most cases as we pass up a stream to its origin we find the valley becoming gradually nar- rower and less deep, until at last we arrive either at a mere rill on the side of a hill, or at a spring rising from a combe in the hillside, and finally at a ridge which forms the watershed. The Upper Engadine forms a remarkable exception. If we look upwards from Cele- 1 Theobald, Beitr. z. Geol. K. d. Schw., L. iii. 352 SCENERY OP SWITZERLAND chap. rina towards the Maloja we see above us a broad valley, which would appear to indicate a great river, the source of which must be miles away. Instead of this we have a succession of lakes, threaded on a small stream, and when we arrive at the Maloja, the main valley, still broad and deep, suddenly ends and we find ourselves on the brink of a steep descent into the Val Bregaglia. The Engadine is in fact a truncated valley, the so-called source of the Inn is in reality merely one of the tribu- taries of the old main river ; and there is no Inn above the Lake of Sils, the sources of supply having been cut off. Nor is it only the main river which has disappeared, but several of the former tributary streams have been carried away into Italy. " If," says Prof. Heim, to whom and to Prof. Bonney our knowledge of these facts is mainly due, " we imag- ine the valley southwards of the Maloja filled with cloud, over which we were looking to the clear heights above, we should see a series of valleys, the Val Ma- rozzo, Val Albigna, so-called from the whiteness of the water, Val Muretto, etc., all converging towards the Inn, of which apparently they were undoubtedly tribu- taries. But the cloud lifts, and we see to our surprise that they open on the southern side of the watershed, and turn sharply down the Val Bregaglia." The slope of the Val Bregaglia being much steeper than that of the Inn (Fig. 152), the river Maira has gradually cut its way back and appropriated more and more of the territory which originally belonged to the Inn. The v/aters of the Val Marozzo, now called the Upper Maira, and the Val Albigna were once tribu- taries of the original Upper Inn, but have been car- ried off into Italy by the victorious Maira. Hence the Upper Engadine at the Maloja is from the first a broad valley, because it represents part of the course of a stream which has lost its head-waters. THE ENGADINE 353 Though the evi- dence is not so strik- ing, we find a similar state of things on the Lukmanier, the St. Gotthard, the Cenis, in fact most of the great Alpine passes, and we may- say with confidence that the watershed between Switzerland and Italy was form- erly further south and is gradually, though of course very slowly, retreating towards the north. Moreover, as already mentioned, the Nagelflue (Mio- cene) deposits of the great Swiss plain be- tween the Alps and the Jura contain many pebbles which must have come from high mountain ranges to the south of the pres- ent watershed, being formed of rocks which do not occur in Switzerland, but are found in the Ital- ian valleys. Another result of 6L09 faimg — gVGS UUTJ[{lBA|Tg— SS9S T* - 0885 oas i9nu[(lBAiis_„ 88S8 ~ ''■^-- £<;9S BtiiioBuas fai'"" 698S BlIS" 9^^s ^- 9885 OBBjasiiS""' 998^ 6T09 ■BiSaoivji" gj-OS on iqaimi ■ ip'T" If 1)1 wmoBX-Bg " 999Z «Tini90!(llY~ 890i ■B.niBnBij-- £865 iWTij ozzojwij— 1399-5559 o^anop 02zozv^~~ iI98i ortrawo 0U'"A"~ flf£ on'BJdosooij^.— eiZ9 ajn^S "eaSiqiv" ■1-3 -BuSicity- 9l6f oiaqiaoi' Z29E opnoa" Of SE onSog- gj-fg onfljioi" CSS5 ■auSssM'isvji- — 1 1 — 354 SCENERY OF SWITZERLAND chap. the change has been the formation of the chain of lakes, St. Moritz, Campfer, Silvaplana, and Sils, which char- acterise the Upper Engadine. Under the former regime the flow of water down the main valley was sufficient to carry off the materials brought down by the lateral tributaries. But since the head-waters have been cut off and carried away into Italy this is no longer the case; hence the lateral streams have built up dams across the valley, thus causing the chain of lakes. The lake at Davos is probably due to a similar cause, the former head-waters of the Landwasser having been captured by the Landquart. (See ante, p. 187.) The Val Bregaglia and the Upper Engadine consti- tute, as already mentioned, one great trough valley. The west half of the Silser See and both sides of the Val Bregaglia as far as Nazarina are Talc Schists, much contorted. Isola stands on a river cone, formed by the stream of the Val Fedoz. The promontory opposite Isola is a ridge of Trias which runs south-west to the Piz Lunghino. Beyond it to the north is Serpentine ; the north-east of the lake is Mica Schist, above which is Granite stretching from Piz Lungen to Piz Munte- ratsch, across which passes the Julier Road. It consists of white or pinkish Orthoclase, green Oligoclase, gray or white Quartz and brown Magnesia, and Mica. These tints make it one of the most beautiful rocks in the Alps. The grains are of medium size. It crosses the valley and extends to Pontresina. Both the Val Roseg, and that of Morteratsch are excavated in it, and it forms a great part of the Bernina mountains, though the actual summit is Syenite-Diorite.^ The Lake of Silvaplana was no doubt once continuous with that of Sils. The flat ground on which Sils stands 1 Theobald, Beitr. z, Geol. K- d. Schw., L. iii, XXIV THE ENGADINB 355 is alluvium brought down by the stream from the Val Fex. On the left side are Triassic strata, the continua- tion of those already mentioned, and beyond them on the left of the lake is Serpentine. On both sides of the Lake Campfer is Granite, and at the lower end Casanna Schist. Fig. 153 shows that, as already mentioned, the valley of the Upper Inn is a trough. When we pass from the Granite of the Julier to that of Pontresina and the Rosatch we might at first sup- FiG. 153. — Section across the Valley of the Inn from P. Julier to G. Surlei. pose that the two banks of the Inn were in direct con- nection. This is however not so, but from Maloja to Scanfs the Inn runs in a trough of Schistose rocks, which separate the Julier from the outposts of the Bernina. They are principally Casanna Schists. The Lake of St. Moritz has Syenite on the west. Gneiss on the north, and Mica Schist on the south. At Celerina we come on the wide stretch of the Upper Inn which stretches to Scanfs. At Bevers is the open- 356 SCENERY OF SWITZERLAND chap. ing of the wild valley of that name which is excavated entirely in Granite. The herbage is excellent and the flora very rich, but the valley is uninhabited in winter. It is almost inaccessible except at. the entrance, the mountains surrounding it being extremely steep. During the Glacial period the great glacier coming down from Pontresina probably blocked up the main val- ley to so great a height that those of the upper district from the Julier Alp, Val Fex, Val Fedoz, etc., were driven over to Maloja and down the Val Bregaglia. Near Celerina is a mass of rock on which the church of St. Gian stands ; it is a quarter of a mile long, and one-eighth of a mile broad, and 150 feet high, rounded at the upper end and precipitous on the north-east tow- ards the lower valley, showing that the ice flow was in the direction of the Inn. On the other hand, at Sils Maria, is a similar mass of rock, with the slope towards the north-east and the precipitous side on the south-west, showing that the ice flow was in the opposite direction. The ice-shed therefore must have been somewhere near Campfer. Just in front of the great Maloja Hotel are some beautiful specimens of Gneiss rocks moutonn^es. The glacier reached a height of over 8000 feet, below which the rocks are rounded and smooth, while higher up they are rough and jagged.^ At Cinuskel the river diverges somewhat to the north of the line of sedimentary rocks, skirting them on the left, and for some distance has crystalline rocks on both banks. The reason of this is not obvious, but we must remember that the denudation has been im- mense, and the deflection is probably due to some cause connected with the strata which have been removed. At any rate from Cinuskel to Guarda the sedimentary 1 Theobald, Beiti: z. Qeol. K. d. iSchw., B. iii. THE ENGADINB 35T strata have been entirely removed on both sides of the river, which flows over crystalline rock. At Zernetz the great crystalline boss of the Monte Baselgia forces the river to make a wide curve, after which it resumes its previous course. On the west side of the mountain the lateral streams join the Inn almost like the spokes of a wheel on some gigantic axle — the Ova Sparsa, Sursura, Susasca, Sagliano, Lavinuoz, and Tuoi. On the other hand the original line of the val- ley, as indicated by the strata, passes in a straighter line to the south-east of the mountain. The mountain itself consists of Gneiss and Crystalline — principally Hornblende — Schist. In the centre of Sc/iisis Fig. 154. — Section across the Valley of the Inn at Tarasp. the boss the strata are perpendicular, with gaping fis- sures of great depth. The small plateau of Ardez is one of the most inter- esting parts of the Lower Engadine. The basis is Granite, which resembles that of the Julier, and in many places comes to the surface. It is often polished, doubtless by glacial action. Fig. 154, representing a section of the Inn Valley at Tarasp, shows that the strata are overthrown into com- pressed folds and the river runs in a synclinal trough.^ 1 Theobald, Beiti: z. Geol. K. d- Schw., L. ii. 358 SCENERY OP SWITZERLAND chap, xxiv From Ardez to Remus the river runs between Lias on tlie left, and (Haupt-Dolomite Trias, on the right, along a line of disturbance through which Granite, Gneiss, Serpentine, and other Plutonic rocks come to the surface. The Liassic rocks of this district fall into undulations, the principal of which is the deep trough which has on the whole determined the course of the Inn, and has also given rise to the mineral springs at Tarasp and Schuls. These are perhaps due to a fracture along the line of the valley. The temperature of the water is not hot nor constant, which indicates that they do not come from any very great depth. From a little below Remus to Prutz the river has Liassic rocks on both banks, which below Martinsbruck takes the form of clay-slate, and through which the deep magnificent gorge of Finstermiinz is cut to a depth of 1000 metres. Speaking of the lower course of the Inn below Lan- deck, Bonney says, " Of a valley of strike the course of the Inn from Landeck to below Jenbach is an excellent example. The river flows roughly from west to east for full 50 miles, bounded on the south by the central range of Crystalline rock, on the north by the overlying lime- stones and shales of the secondary series. It receives the drainage of many considerable lateral valleys from the former, of sundry glens from the latter. The junc- tion of two great rock groups, differing so markedly in their powers of resistance, has obviously determined the initial course of the river valley, which broadens as the stream descends from a height of 2750 feet to about 1700 feet." 1 1109. Bonney's " Growth and Sculpture of the Alps," in Tyndall Lectures. Koy. Inst., 1888, CHAPTER XXV GENERAL SDMMARY In the preceding chapters I have endeavoured to trace the causes which have led to the present scenery of Switzerland. In Permian times there were probably mountains where the Alps now rise, but this ancient range was gradually removed by denudation; moreover the land sank, and during the Permian, Liassic, Jurassic, and Cretaceous periods there was deep sea where the Alps now rise. There were certainly great changes of level, but they were all continental, and that is to say they were approximately the same for the whole area, there was no compression and no folding. That the sea during this period must have covered the site of the present Alps is proved (1) by the fact that we find no trace of its southern shores, no littoral de- posits. If the Alps had then existed, pebbles, etc., from them must have been found in the Liassic, Jurassic, and the Cretaceous rocks. This is not the case : indeed these rocks contain no pebbles of any kind, and the fos- sils in them are all indicative of deep water far away from land. There are no conglomerates or gravel beds between the Permian and the Upper Eocene. Again (2) we find remains of the Secondary strata protected in the troughs of the folds. These sedimentary deposits therefore extended completely over the site of the pres- 359 360 SCENEEY OP SWITZERLAND chap. ent mountains, and though no extensive remains of these deposits now occur in the Central Alps, this is because they have been entirely stripped away. The elevation of the country was due, not to upheaval from below, but to lateral pressure owing to the cooling and consequent contraction of the earth. It has been calculated that the strata between Basle and Milan, a distance of about 130 miles, would, if extended horizon- tally, occupy 200. There has consequently been a shortening of no less than 70 miles. For some time the central ranges alone were above the water, and the mountain torrents brought down gravel and boulders, forming the " Nagelflue " of the Rigi and the Central Plain. The Alps therefore, from a geological point of view, are very recent. Our Welsh hills, though comparatively speaking insignificant, are far more ancient. They had been mountains for ages and ages before the materials which now compose the Rigi or the Pilatus were depos- ited at the bottom of the sea. Indeed we may say that it is because they are so old that they have been so much worn down: the Alps themselves are crumbling, and being washed away ; and if no fresh elevation takes place, the time will come when they will be no loftier than Snowdon or Helvellyn. They have already undergone enormous denudation, and it has been shown that from the summit of Mont Blanc some 10 to 12,000 feet of strata have been already removed. The conglomerates of Central Switzerland, the gravels and sands of the Rhine and the Rhone, the Danube and the Po, the plains of the Dobrudscha, of Lombardy, of South France, of Belgium and Holland, once formed the summits of Swiss mountains. This amount of denudation gives us, I will not say a meas- ure, but at any rate a vivid idea of the immense time x^v GENERAL SUMMARY 361 that must have elapsed since the Alps rose out of the sea. Denudation began as soon as the land rose above the sea and the main river valleys were excavated. Then came a period of cold known as the Ice age or Glacial period. Round all the high mountains, and over many of them, are great fields of ice and snow, terminating in glaciers. These, however, are but the remnants of a much larger sea of ice which once covered almost the whole country. The glacier of the Rhone for instance descended the Valais, filled the Lake of Geneva, rose to what is now a height of 1350 metres on the Jura, and then dividing, sent one branch as far as Lyons, and a second along the Aar to Waldshut. The Glacial period, however, was not continuous, but interrupted by at least two periods of more genial climate. The mass of material brought down from the mountains partially filled the river valleys (which have not even yet been entirely re-excavated), formed great moraines, and is spread in thick, but irregular, masses over all the lower ground. The rivers of Switzerland run mainly in one of two directions, the first from south-west to north-east, or vice versa, following the strike and original folds of the strata, and the second at right angles to it. Many, indeed most, of the principal rivers, take first the one and then the other direction in different parts of their course. In some cases the rivers cut through mountain ranges, as for instance the Rhone between Martigny and the Lake of Geneva. This probably indicates that the river is older than the mountain range, and cut through it as it rose. The river system of Switzerland was, however, at first very different from the present. The Vosges and the 362 SCENERY OP SWITZERLAND "JAP. Black Forest were continuous, the subsidence which now separates them not having yet taken place, so that the Rhine Valley at Basle was not in existence. Nor had the gorges by which the Rhone finds its exit through the Vuache yet been formed, and the conse- quence was that the whole drainage of Switzerland north of the Alps found its way by the Danube to the Black Sea. For some time after the subsidence of the Basle Valley had taken place the upper waters of the Rhone still joined the Rhine, and ran over the plains of Germany to the North Sea ; finally, however, it broke its way by the E'ort de L'Ecluse, and falling into the SaSne, runs to the Mediterranean. Another general change in the river system is that the crest of the Alps has retreated northwards. The southern slope being much steeper than that to the north, the Italian rivers hkve more power of erosion than their northern rivals, and are gradually eating their way back. The Upper Engadine is a conspicuous example. Many minor changes have taken place: partly (1) through recent changes of level, as for instance that which has diverted the Reuss from its old course by the Lake of Zug, and driven it round by Lucerne ; partly (2) by rival rivers deepening and extending their val- leys and thus annexing territory which previously be- longed to othei's : for instance, the Landquart has robbed the Landwasser of its headwaters and carried off the Schlappina, the Vereina, and the Sardasca ; partly (3) by dams due to river cones or glacial moraines, as for instance the Limmat which was driven from the Glatthal and the Sihl from the valley of the Lake of Ziirich. The lakes which contribute so much to the beauty of the country fall into several different categories. ^■^ GENERAL StTMMAEY 363 1. Some are due to the inequalities in the glacial deposits ; as the numerous small pieces of water in the curious district of the Pays de Dombes. 2. Some are due to subsidence; strata, generally those of gypsum or salt, having been dissolved and removed; as for instance the Lakes of Cadagno and Tremorgia. 3. Some are dammed back by river cones, as the lakes of the Upper Engadine ; or by moraines, as the Lakes of Sempach, Baldegger, and Hallwyl. 4. The origin of the larger Sv^iss lakes has been the subject of much discussion. The opinion novs^ prevalent among Swiss geologists is that they are mainly due to recent changes in level, and are in fact drowned river valleys. Even more striking than the exquisite beauty of the lakes is the grandeur of the history they unfold, and of the causes to which they are due ; and indeed in contemplating the general Scenery of Switzerland we cannot but be profoundly impressed by the enormous magnitude of the changes, and the irresistible forces which have been brought into operation. Those forces have affected the general configuration of the Earth's surface. Attention has often been called to the fact that so many great masses of land point southwards — South America, Africa, India, etc. Many of the peninsulas, moreover, have an island, or group of islands at their extremity, as South America, which is terminated by the group of Tierra del Fuego ; India has Ceylon; Malacca has Sumatra and Borneo; the southern extremity of Australia ends in Tasmania or Van Diemen's Land; a chain of islands runs from the end of the peninsula of Alaska; Greenland has a 364 SCENERY OE SWITZERLAND group of islands at its extremity ; and Sicily lies close to the southern termination of Italy. Some years ago I ventured to suggest ^ that we might correlate this with the remarkable preponderance of ocean in the southern hemisphere, which M. Adh^mar has suggested to be due to the alteration of the centre of gravity of the Earth, caused by the great southern cupola of ice. However that may be, the preponderance of water in the south is very remarkable. Taking each parallel as unity, the proportion of sea is as follows : — 60 North . 0,892 10 South . 0,795 50 " . 0,438 20 " 0,763 40 " . 0,538 30 " . 0,797 30 " . 0,567 40 " . 0,961 20 " . 0,574 50 « . 0,983 10 " . 0,758 60 " . 1,000 " . . 0,783 Without at the present moment entering upon any discussion as to the cause which has produced this remarkable result, the fact at any rate seems to throw some light on the southern direction of promontories. For let us suppose three tracts of land, each trending north and south, each with a central backbone, but one with a general slope southwards, one with a northward slope, and the third without any. The first will, of course, form a peninsula pointing southwards, because, as we proceed southwards, less and less of the sui'face will project above the water, until nothing but the central ridge remains. The second tract, however, would also assume the same form, because, though by the hypothesis the land does not sink, still, the 1 Nature, 1877. See also a paper in the Journ. Boy. Geogr. Soc, 1895. XXV GENERAL SUMMARY 365 gradual preponderance of water would produce the same effect. If, moreover, the central mountain ridge, as is so generally the case, presents a series of detached sum- mits, the last of such elevations which rises above the water level will necessarily form an island. This sug- gests a possible reason why Africa, unlike the other south-pointing lands, has no island at its extremity. They are folded ranges. The Cape of Good Hope, on the contrary, is a table mountain, bounded by two con- verging areas of subsidence which meet at Cape Town. Lastly, in the third case, the gradual diminution of water would tend to neutralise the effect of the slope, and if the two were equal, the land would form — not a pointed peninsula, but an oblong track. So far as I am aware, no notice has been taken of this suggestion except by Prof. Penck, who characterised it as self-evident. However this may be it had not been previously pointed out, and indeed an objection, to which for long I saw no answer, was suggested to me by Mr. Francis Galton. He urged that no accumulation of water in the northern hemisphere would give promon- tories pointing to the north. I tried various hypotheti- cal enlargements of the northern seas, but in vain. The explanation lies, I think, in the necessary equivalence of the great folds on the Earth's surface. If folded mountains are due, as above suggested, to a diminution of the diameter of the Earth, every great circle must have participated equally in the contraction. The east and west folds would, on the whole, counter- balance to those from north to south. This must be so theoretically, but we have no means of testing it by exact figures. It is interesting, however, to observe that while the mountain chains of the Old World run approximately from east to west, those of America are, 366 SCENERY OP SWITZERLAND chap, xxv in the main, north and south. Speaking roughly, the one series would seem to balance the other, and we thus get a clue to the remarkable contrast presented by the two hemispheres. Again, in the northern hemisphere we have chains of mountains running east and west- — the Pyrenees, Alps, Carpathians, Himalayas, etc. — while in the southern hemisphere the great chains run north to south — the Andes, the African ridge, and the grand boss which forms Australia and Tasmania. This, then, seems to me the answer to the difficulty suggested by Mr. Galton. The mountains in the south- ern hemisphere running north and south give us, when combined with the preponderance of water, the southern- pointing promontories. No such preponderance, how- ever, in the northern hemisphere would give us northern- pointing promontories, because there the great folds run not from north to south, but from east to west. Thus, then, the explanation of great mountain ridges by lateral pressure and consequent folding, coupled with the necessity of approximately equivalent contrac- tion along every great circle, explains the balance of east and west and north to south chains in each hemis- phere, and this again, in conjunction with the prepon- derance of water in the south, explains the tendency of land masses to taper southwards, and end with an island or group of islands, thus throwing an interesting light on some of the principal features in the configuration of the Earth's surface. APPENDIX LIST OF WORKS AND MEMOIRS REFERRED TO Memoirs on the Geological Map of Switzerland; prepared under the Supervision of the Swiss Geological Commission. Lief. 1. Basle. By A. MiiUer, 1864. 2. Graubunden. By G. Theobald, 1864. " 3. " " 1867. " 4. Aargauer Jura. By C. Moesch, 1867. 5. Pilatus. By F. J. Kaufiuann, 1867. 6. Jura. By A. Jaccard, 1869. 7. " " 1870. Supplement, 1893. " 8. " By J. B. Greppin, 1870. " 9. Wallis. By H. Gerlach, 1872. " 10. Jura. By C. Moesch, 1874. " 11. Bern (Rigi and Central Switzerland). By F. J. Kauf- mann, 1872. " 12. Fribourg, Montsalvens. By V. Gilli^ron, 1873. " 13. Sentisgruppe. By Escher von der Linth, 1878. '• 14. St. GaUen. By Escher von der Linth, Gutzwiller, Kauf- mann, and Moesch, 1874. " 15. Gotthardgebiet. By Karl v. Fritseh, 1873. " 16. Alpes Vaudoises. By E. Renevier, 1890. " 17. Ticino. By Torquato Taramelli, 1880. " 18. Vaud, Fribourg, and Berne. By V. Gillidron, 1885. " 19. St. Gallen, Thurgau, and Schafihausen. By Gutzwiller and Schalch, 1883. " 20. Berner Alpen. By A. Baltzer, 1880. " 21. Aarmassiv. By E. v. Fellenberg and C. Moesch. " 22. Berne, Vaud, Fribourg, Valais, and Chablais. By H. Schardt, E. Favre, G. Ischer, 1887. " 23. Graubunden, Tessin. By Fr. Rolle, 1881. " 24. Central Sohweiz. By Baltzer, Kaufmann, and C, Moesch, 1886, Supplements, 1887, 1888. 367 368 SCENERY OP SWITZERLAND Lief. 25. Reuss and Khein. By Alb. Heim. 28. Monte Rosa. By C. Schmidt. 27. Penninischen Alpen. By H. Gerlach, 1883. 28. Mont Blanc. By A. Favre, 1884. 29. Die vier Eckblatter. 1887. 30. Bern. By A. Baltzer, Fr. Jenny, E. Kissling. 31. Nordschweiz. By Leon du Pasquier. 32. Bodensee, Thunersee. By C. Burckhardt, 1893. 33. Iberg im Sihlthal. By E. C. Quereau. Agassiz. fitudes sur les glaciers, 1840. Ball. On Alpine Valleys and Lakes. Lond. and Edinb. Philos. Mag., 1863. Baltzer. Der Glarnisch. " Die Hochseen der Schw. Alpen. Humboldt, 1883. BoNNEY. Alpine Regions. Growth of the Alps. Alpine Journal, 1888, 1889. « The Story of our Planet. BocEDON. Le Canon du Rh6ne. BuU. See. Geol. de France, 1894, 1895. Bkockedon. Passes of the Alps. Cezanne. Etudes sur les Torrents des Hants Alpes. Charpentiek. Essai sur les Glaciers. CoAZ. Lawinen in den Schweizer Alpen. Bern, 1881. CooLiDGE. Swiss Travel and Swiss Guide Books. Credner. Die Reliktenseen, 1887. Croll. Climate and Time. Davison. On the straining of the Earth from secular cooling. Proc. Roy. Soc, 1894. " Cooling of the Earth's crust. Philos. Trans. Roy. Soc, 1887. De Saussurb. Voyages dans les Alpes. Desor. Die Moraine Landschaft. Verb. d. Schw. Nat. Gesellsch., 1872, 1873. " Der Gebirgsbau der Alpen, 1865. DiENER. Der Gebirgsbau der Westalpen. Emden. Uber das Gletscherkorn. Neue Denkschrift, V. 33, 1891. Falsan et Chantre. Monogr des Anc. Glaciers du bassin du Rhone, 1891. Favke. Recherches Gdolog. de la Savoie, etc APPENDIX 369 Favhe. Desc. Gi^ol. du Canton de Geneve, 1880. Fellenbekg. Berner Alpen. Journ. Schw. Alp. Club. Bd. 12, 1887. Fisher. Physics of the Earth's Crust. Forbes. Travels in the Alps. Fraas. Scenerie der Alpen. Fruh. Beitr. zur Kenntnis der NageMue. Neue Denkschriften, 1890. Gastaldi. Terr. sup. d. la Vallde du Po. Bull. Soc. Geol., 1849, 1850. " Glacier erosion in Alpine Valleys. Quar. J. Geol. S., 1873. Geikie, a. Text-book of Geology. " J. The Great Ice Age. Gilbert. Geol. of the Henry Mountains. United States Geol. Survey, 1877. Greenwood. Kain and Rivers. Gremaud. Etudes sur les valldes primitives et les valines d'^rosion de Fribourg. Bull. Soc. Frib. des So. Nat., 1888. Gi'MBEL. Alpengebirge. " Geologic aus dem Engadin. Journ. d. Nat. Gesel. Graubunden, Jahrg. 31. GuYOT. Sur la distribution des especes des roches dans le bassin du Rh6ne. Bull. Soc. Neufchatel, vol. i. Hagenbach. Le Grain du glacier. Arch. Sc. Phys. Suisse, 1882. Haug. Origine des Prealpes Komandes. Arch. d. sc. Genfeve, 1894. Heer. Monde primitive de la Suisse. Heim. Entstehung der Alpinen Eandseen. Viertelg. Nat. Ges. Zurich, 1894. " Erosion im Reussgebiet. Journ. d. Schw. Alp. Clubs, 1879. " Handbuch der Gletscherkunde. " Mechanismus der Gebu-gsbildung. Geol. Monogr. d. Todi- und Windgallen-gruppe. 2 vols. Heim and De Makgerie. Les dislocations de I'ecorce terrestre, 1888. HuGi. tlber das Wesen der Gletscher und Winterreise in das Eismeer, 1842. Leblanc. Sur la relation qui existe entre les grandes hauteurs, les roches polies, les galets glaciaires, les lacs, etc. Bull. Soc. GeoJ.,, Paris, 1842, 1843. 2b 370 SCBNBEY OP SWITZERLAND Lentheric. Le Rh6iie, histoire d'un fleuve. LivRET Guide. Geologique dans le Jura et les Alpes. Pub. par le Comity d'organis. en vue de la vi« Session k Zurich, 1894. Lloyd. Physiography of the Upper Engadine. Lory. Str. des Mass. Centr. des Alpes. Bull. Soc. Geol. d. France, V. 3. " Gonstr. Mass. Cryst. des Alpes Occid. Congr. G^ol. int. London, 1888. LuGEON. Geol. du Ghablais. Bull. Soc. Geol. de France, 1893. Lyell. Principles of Geology. Martins. On ground moraine. Revue des deux mondes. Bull. Soc. Geol. d. France, 1841, 1842. Mayer. Le Mer glaciale an pied des Alpes. Bull. Soc. Geol. France, 1875, 1876. Millard Reade. Origin of Mountain Ranges. Mojsisovics. Beitr. z. Topischen Geol. d. Alpen ; des Rhaetikon. Journ. Geol. Reichsamt. Wien, 1873. MoRLOT. Sur la subdivis. du terrain quatern. Bibl. univers, 1855. MtJHLBERG. Exc. in Basler und Solothurner Jura. Eclog. Geol. Helv., 1892, 1893. " Geol. Verh. des Botzbergtunnel, etc., 1887-1890. MuRCHisoN. On the Structure of the Alps. Quart. Jour. Geol. Soc, 1848. MusY, Prof. M. Le Canton de Fribourg. Dis. k I'Ouv. 74" Sess. Ann. Soc. Helv. d. Sci. Nat. Fribourg, 1891. NoE and De Makgerie. Les Formes du Terrain. Penck. Die Donau. " Die Vergletscherung der Deutschen Alpen. " Morphologie der Erdoberflache. Philippson. Studien'iiber Wasserscheiden. Leipzig, 1886. Playpair. lUustrat. of the Huttonian theory, 1802. Prestwich. Geology — Chemical, Physical, and Stratigraphical. Ramsay. On Lakes. Quart. Jour. Geol. Soc, Aug. 1862. Philos. Mag., 1864. " On the Excav. of the Valleys of the Alps. Philos. Mag., 1862. Eeclus. La Terre. Renevier. Mem. Geol, sur 1. Perte du Rh6ue, 1854. " andGoLLiBz. Alpes Centrales et Occidentales. Livret Guide Geol., 1894. RiCHTHOFEN. Fiihrer ftir Forschungsreisende. APPENDIX 371 RoLLiER. Sur les Lapiees. Bull. Soc. Sc. Nat. Neufchatel, 1894. KoTHPLETZ, A. Geotectonische Probleme, 1894. RiJTiMEYER. Eiszeit und Pliocene auf beiden Seiten der Alpen. Basel, 1876. " Der Rigi. " tJber Thai- und See-bildung. Saracin. De I'origine des roches exot. du Flysch. Arch. Sc. Geneve, 1894. ScHAKDT. Struct. Geol. des Alpes Frib. et Vaud. Bib. Univ. Geneve, 1891. " Chaine du Reculet-Vuache. Eclog. Geol. Helv., 1891. ScHLAGiNTWEiT. Nsue Unters. ti. d. phys. Geogr. d. Alpen, 1850. Schmidt. Die Klippen und exotischen Blijoke im Flysch. Act. See. Helv. Sc. Nat. Fribourg, 1891. " Geologie de Zermatt. " Geol. du massif du Simplon. Arch. Sc. Phys. and Nat. Geneve, 1895. ScROPE. On the Origin of Valleys. Geol. Mag., 1866. Staff. Geol. Prof, des St. Gotthard. Bern, 1880. " Geol. tibersichtskarte der Gotthard Bahn., 1885. St0dbr. Index der Petrographie. " Geplogie der Schweiz. " Lehrbuch der physikalischen Geogr. und Geol. SuEss. Entstehung der Alpen. " Das Antlitz der Erde. SupAN. Studien iiber die Thalbildung der ost. GraubUnden, 1877. TARsiJTZER. Waiiderungen in der BUndnerischen Triaszone. Jour, der Nat. Ges. Graubiinden, 1893. " Der Geol. Bau des Rhaetikon. Journ. d. Nat. Ges., Graubunden, 1892. " Die Gletschermiihlen auf Maloja. Tyndall. Forms of Water. " The Glaciers of the Alps. " Hours of Exercise in the Alps. Violet le Due. Le Massiv d. Mont Blanc. 'Walton. Peaks in Pen and Pencil. Edited by Bonney, 1872. Whympee. Scrambles amongst the Alps, 1871. Wills. Travels in the High Alps. the end THE MACMILLAN COMPANY'S PUBUCATIOHS. PLEASURES OF LIFE. The Right Hon. Sir JOHN LUBBOCK, Bart., M.P., P.R.S., D.C.L., LL.D. Cloth, ailt top. i2mo. $1.25. " A good wholesome book. The literary variety of expression is charming." — Home yournal. 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