Ik" THE GIFT OF A-^8BH^3 : >i:|.lx] x^-vH- 3777 CORNELL UNIVERSITY LIBRARY 3 1924 091 786 099 mi Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924091786099 ( ¥v&hi!id^ ''iimM-mi { >, Y0LA. '-nAILCii^COIG Ayiii|]Sl£^;t,UW(ln ilJilU:. AlfeRHY "MAI-ICH THEN TiJ bATTLL,AHD T;ill4H(jf YOlll, AH<;Esinp;i ANC' THINK ip YOUR POSTERITY." THE PICTOEIAL HISTORY OF SCOTLAND A.D. 79 — 1746. BY JAMES TAYLOR, D.D., ASSISTED BY PROFESSOR LINDSAY, D.D., PROFESSOR EADIE, D.D., L.L.D., JOHN ANDERSON, D.D., GEORGE MACDONALD, ESQ., F.E.I.S., AND OTHKK CONTKIBUTOES. IN TWO VOLUMES. VOL I ILLUSTRATED WITH ENGRAVINGS ON STEEL. NEW YOEK: VIRTUE, YORSTON AND COMPANY, 13 D E T S T II E E T . TO SIE DAYID BEEWSTEE, K.H., D.C.L., LL.D., F.R.S., V.P.R.S. Edin., M.R.I.A., F.R.A.S. ; ASSOCIATE OF THE IMEEEIAl INSTITUTE OP PKAUCE ; HONOBAHY, OK CORRESPONDING MEMBER OP THE ACADEMIES OP ST. PETERSBURG, VIENNA, BERLIN, COPENHAGEN, STOCKHOLM, BRUSSELS, GOTLINGEN, MODENA, AND OF THE NATIONAL INSTITUTE OF 'WASHINGTON; AND PRINCIPAL OF THE UNITED COLLEGE OF ST. SALVADOR AND SI. LEONARDS, ST. ANDREW'S, THIS VOLUME IS BESPECTrCTLLT DEDICATED BX HIS FRIEND, JAMES TAYLOR CONTENTS OF YOL. I. Geology or Scotland i- CHAPTER I. A.D. The Roman Period — CHAPTER II. The Caledonians ...... — CHAPTER III. Pictish Period 446—843. CHAPTER IV. The Scottish Period 843—1097. CHAPTER V. Ecclesiastical History .... 563—597. CHAPTER VI. Scoto-SaioD Period 1097—1306. CHAPTER Vll. Robert Bruce 1306 — 1329. CHAPTER VIII. Robert Bruce 1329—1330. CHAPTER IX. Ecclesiastical History diiriog the Scoto-Sason Period .... 1097-1329. CHAPTER X. State of the Country 1097-1329. CHAPTER XI. David the Second 1329— 1346. CHAPTER XII. The Parliament of Scot land— Laws — Charters — Royal Buri;hs - - Trade and Commerce— Coinage — Weights and Measures — Houses, Military Arms, and Dress— Sports and Amusements 1097—1370. CHAPTER XIII. Robert the Second 1370—1390. CHAPTER XIV. Robert the Third 1390—1424. CHAPTER XV. James the First 1424—1437. PACK 1 23 33 59 113 140 166 172 CHAPTER XVI. Ecclesiastical History A.D. PJGE 1370-1436. 275 CHAPTER XVII. Condition of the People . . . . 1370-1436. 280 CHAPTER XVIII. Language and Literature during the Thirteenth, Eourteenth, and Fif- teenth Centuries 1285—1437. 289 CHAPTER XIX. James the Second 1436—1460. 316 CHAPTER XX. James the Third 1460—1488. 346 CHAPTER XXI. Condition of the People .... 1436—1488. 365 CHAPTER XXII. James the Fourth 1488-1513. 378 CHAPTER XXIII. James the Fifth 1513—1542. 411 CHAPTER XXIV. Literary History of the Period . . 1494—1557. 474 CHAPTER XXV. Condition of the People .... 1488—1542. 532 j CHAPTER XXVI. ,r., Mary. — [From her accession to her •'°'* departure for France.] . . . . 1542—1548. 562 Mary . CHAPTER XXVII. 1548-1561. 615 213 224 238 CHAPTER XXVIII. Ecclesiastical History 1542—1560. 6C0 CHAPTER XXIX. Mary 1561—1565. 698 CHAPTER XXX. Mary 1565—1567. 750 258 Appendix 774 DIRECTIONS FOR PLACING THE PLATES Clje ^ittaiid $tstorii of Swtkitir. VOL. I. Page Galgacus adJressiug his Army .... Vignette. Jlap of Scotland 1 Coins of tlie Roman Period 6 Specimens of Roniaa Remains 15 Ancient native Weapons 10 lilibtrations of Scottist Archa;oloa:v — Plate I. . . 19 „ ^" Plate II. . . 20 Norliam Castle 6] Seals and Coins of David I. and Alexander I. . . . Gi „ of Malcolm IV., William I., &e 68 Seal and Coin of Ale.vander II., &e 75 LarRS 79 Seal of Jolm Baliol, &c 89 Coronaliou Chair in Westniiiister Abbey .... 92 Portrait of Sir William Wallace 94 Scene of llie Battle of Stirlin,2; 9G ]")nDst3ffuai;e Castle, Locb Etive 127 Plan of Bauiiockbiirn 133 Field of Bannockburn 136 Seal, Coins, and Skull of Robert Bruce 162 Kelso Abbey 166 I'ajre Interior of Roslyn Chapel 168 Great Seal of Robert II., &c 224 Portrait of James 1 258 Roxburgh Castle 343 Linlithgoiv Palace 403 Twisel Bridsje 405 Plan of the Battle of Flodden 407 Floddea Field 408 Portrait of .James V 462 Holyrood Chapel 561 Portrait of Cardinal Beaton 597 „ of Queen Mary ^ . . . 659 Queen ^Mary's Bedchamber 704 ilm'der of David Rizzio ib. Queen Mary's Closet 760 GEOLOGY OF SCOTLAND. Curved Gneiss in Lewis x Fossils of the Old Red Sandstone ixvi ,, ,, Carbotiiferous System i Staffa from the South-west Ixxxi VOL. II. Page Prince Charles entering Edinburgh . . Vignette, Craigmillar Castle 36 Lochlevcn 68 Portrait of Regent Moray 78 Langside 84 Dundreiman Abbey ib. Escape of Botlnvellhangh 114 Dunljartoii Castle 126 Effigy of .Mary Queen of Scots 237 Portrait of .To'hn Knox 266 ■ „ of George Buchanan 290 Past Castle . " 381 Illustrations of the Gowrie Conspiracy 385 Portrait of Queen Elizabeth ........ 398 of James VI 417 Newark Castle 495 Philiphaugh 629 Portrait of Charles I. . 650 ), of James, First Marquis of Montrose . . . 659 Peaths Bridge and Ravine 662 Pafffl Plan of the Battle of Dunbar 663 Portrait of Cromwell 677 of Charles II 682 „ of Archibald, first Marquis of Argyll . . 686 Grass-market, Edinburgh 708 Murder of Archbishop Sharpe 710 Scene of the Battle of Drumclog 712 Bothwell Bridge 713 Portrait of Graham of Claverhouse 727 of James VII 728 The Pass of Killiecrankie 786 The Field of Killiecrankie 787 Braemar Castle 846 Sherilfmuir 868 Portrait of the Chevalier St. George 871 ,, of John, Duke of Argyll and Greenwich . . 881 Palace of Holyrood 923 Battle Field of Preston Pans §27 Falkirk 942 Portrait of Charles Edward Stewart ...... 955 GEOLOGY OF SCOTLAND. GEOLOGY is ttat branch of science wliicli relates to the structure of the earth, the mineral constituents of its mountains and other rocky masses, and the causes which have contributed to the relative distribution of land and water over its surface. It thus embraces physical geography as well as a consideration of the various changes that have rendered the planet so suitable a habitation for organised beings, recent and extinct. The researches of the geologist clearly show that the surface of the earth has not always been as it now is— that there have been various modifications, from time to time produced, of its superficial arrangements— that the sea and land have repeatedly interchanged places — and that gradually, and not all at once, it haa assumed an external configuration so admirably adapted for sustaining life, more es- pecially human life, in its highest type of organised matter. The qualities and varieties of the rocky strata, their vertical arrangement and position, no less than their diversity into mountain and plain, river and ocean bed, demonstrate them to be the work of a designiag cause, of the All-wise and Almighty Creator. Rdftks are neither the offspring of chance, nor the accidental effect of causes that might have generated a whoUy different product, without effecting the end for which they were created. The marks of intelligence and benevolence vnth which they are everywhere stamped, and the important office they fulfil in determining the condition of the human race, in their migrations and occupancy of different territories, evince a designing purpose in their arrangement, distribution, and mineral con- stituents. It is solely in consequence of these conditions, that the earth is fitted, in so eminent a degree, to be the residence of such an order of beings as man, whereby they are divided into nations and communities ; separated by seas, continents, and islands ; and are impelled to seek the means of subsistence, civilisation, and improve- ment, by ingenuity and exertion. This constitution of the earth has, accordingly, produced a most decisive influence on their physical, social, and moral condition. The character of the strata which constitute the surface, the nature of the metals imbedded beneath, and the broken and dislocated position into which both have been thrown, rendering them at once accessible and workable, have contributed to the very existence of our commerce and arts j to the extension and improvements of agriculture, manufactures, and navigation in every country of the world. A different arrangement of the mineral masses, or of even a few of the geographical features of the earth, would have greatly altered its physical adaptations to the human family, changed the relations of large portions of its inhabitants to each other, given a different direction to their pursuits, and issued in a different history. b ii GEOLOGY OF SCOTLAND. Thus, for example, had any of the great mountain ranges of the vorld heen altered in their direction and height, or of the seas and oceans in their free opening into each other, or had the continents extended from pole to pole, and what a different state of things would have prevailed over the surface' The dispersion of the race from the eastern cradle of their birth, their subsequent intermixtures^ their occupa- tion of particular countries, and their final circumnavigation of the globe, would not have taken place in the manner and time, nor been attended with the same ben&ficial results, that have issued under the existing disposition of things. Trans- plant the Himalaya, with their lofty table-lands, across Northern Europe, dividing Russia from Germany instead of Thibet from India, and, along with an entire change in the cliDaate and productions of these nations, the agency of the tribes on one another would have operated very differently, both in Europe and in Central Asia. Instead of the hardy intelligent Teutonic, Anglo-Saxon, and other races, sprung from the Japhetic stock which inhabit Great Britain, and her world-wide colonies, a degenerate caste would have risen up, and retarded the progress of civili- sation. Had Africa, instead of projecting from Europe; to the Soath, stretched to the West, and joined the continent of America, the whole historj' of the world, ancient and raodern, would have been changed : the black NegKp of the tropics, and the red Indian of the wilderness, would, ages ago, have ihvad^. each other's ten-i- tories, mingled with each other's blood, and modified each other's habits. Europe and the Atlantic side of North America would have been isolated from the southern pari; of ihe globe, and Spain and Portugal would have had no part nor lot in the produce and treasures of the western world. The plains- of Italy and France, it can be established on geological data, emerged from the sea shortly before, or nearly coincident with, the historical era. Had that physical event been prevented, which it migfit 'have Been, or even delayed, by the shifting of the subterranean forces that caused their elevation, and what mighty influences woiild have been withdrawn, through their operation upon Roman and Galilean States, from modifying the con- dition of every civilised people in the world— in their language, arts, literature, his- torj; government, and religion ! Now, one main object of Geology is to investigate the nature of the causes which led to the actual condition of the earth's surface and rendered it so convenient an abode for man, as well as the kinds of animals and plants which existed in the past epochs of ' its history, and are now entombed in its rocky strata. The rocks, for miles deep, have been severally examined. The earliest appearances of or- ganic life have been traced. The place of the metals and of the richest minerals have been accurately explored. Five hundred genera, and eight hundred to a thousand species of the larger families of vertebrate animals, and a thousand genera and species of fossil plants, have been restored to human investigation and spread out in the cabinets of natural history. With such disclosures it may be safely aveiTed that no subject within the compass of human research has been attended with more benefi- oial practical results, or more brilliant discoveries into the past history of the planet, than have attended with such rapidity, variety, and number, the investigations of the geologist. There can be none more improving in extending our acquaintance with nature — none more calculated to give cheerful, healthful recreation — and none more directly fitted to raise the mind to wonder and admiration, while contemplating the works of the great architect of the universe. The earth has been the cradle, so will Jt be the grave of all our race. Hence the legitimate desire to learn its origin and its cause, the manner of its formation, and the laws of its continued coiirse. FOSSILS CHARACTERISTIC OF THE CARBONIFEROUS SYSTEIM. 1. Apiocrimtes Totund-us. 2. Body of Actinocrmus. 3. Prcducta scabriculTLB. ■i, Inoceramua vetiiatiis. 5. Belleioplioa. 6. Leptasna . 7. OrLLoceratite. 8. AtmaonitGs Listeri, So-\ , 9. Pecteu papyraceiis. Sow. 10, Spirifer trigonalis . 11, EiioraplLalTxs . 12,FragmerLt c£ Encrini-tal Limestone.- 13. MGgaliclitlE)'s 'Hibhevti, Ag.- 'Ediiib-uTgli coal-field,BatuTalsize. 14?,Ligii.lS3. Lepidod.e]idTon. .Stem.l)eTg,ii , 15. Ligr_16Z . Stem Sc Roofs of a Sigillaria . GEOLOGY OP SCOTLAND. iii Geology has a claim to be regarded as History — -Antiquarian History — ' a record of events whicli lie in the far distant past. The rocks of Scotland, de~ scribed in the following pages, belong most of them to the oldest formations in tlie world. None go deeper into the crusty or can be ascribed to the operation of anterior secondary causes. The fossil remains, contained in the lower stratified series, con- sist of the earliest types of organised bodies anywhere detected in the strata of the earth. The testimony of their existence as living substances, vegetable and animal, in very remote periods of time, and now incorporated as parts of the solid rocli, is of a nature not to be resisted: it speaks at once to the senses and the understanding as alike credible and satisfactory. The more ancient periods of Scottish history are 'nvolved in doubt and fable : the first settlers in the island, whence they came, the line of the earliest kings, and the system of the Druidical priesthood, are matters still of uncertainty. The evidences of Geology, whose memorials are infinitely older, rest upon direct observation; nay, the older the chronicles here, the less uncertainty is there as to their reading, where the registers are all engraven in the most legible characters, and, to be understood, have only to be examined and com- pared with existing forms of life. A state of things, in the most lucid order and form, has thereby been revealed in the vegetable, animal, and mineral kingdoms, very different from anything in existing nature — plants genericaUy distinct from all living types — animals whose families have all passed away — and systems of rocks (vhich can no longer be produced by any visible agencies, under existing arrangements. The physical outline of Scotland is very much influenced by its geological con- ditions. The headlands, bays, creeks, and valleys, are aU determined, less or more, by the peculiar forniations and the disposition of the rocks. Hence the exceedingly irregular form of the coast-line, as presented on maps, where exposea to the action of the sea. The localities of the different mineral substances of the primary and secondary rocks, are readily distinguishable by the long sea-arms or other indenta- tions upon the shores, where, in their stronger resistance to its erosive action, the older rocks generally occupy the capes and headlands, while the newer, from their softer texture, as limestone and sandstone, have been penetrated, washed away, or exposed in isolated patches. The islands, and especially the islands on the western coast, have in this manner been detached from the mainland, their chief mass and lofty ridges consisting of the hardest crystalline rocks, and presenting along the beaches only narrow stripes of those more easily eroded. The great straths and valleys, again, are all determined in their direction and extent by the position and bearing of the moun- tain chains, as the valleys of the Spey, Dee, Tay, Forth, Tweed, and Teviot, which have all an easterly course corresponding with the mountain summits ; they all lie nearly parallel to each other, and the rivers, with their tributaries, all pour their waters into the German Sea. The line of bearing is nearly E.N.E. by W.S. W. ; and with scarcely a single exception, every class of rocks, whether occupying the plains or lining the uplands, or caping the ridges, range from sea to sea across the island. Hence a description of any particular locality, in respect of the same series of rocks, will be found of general application over the mainland; where the continuity is broken by straths, lakes, or arms of the sea, the particular formation can be easily recognised on the opposite sides. The student may, therefore, indifferently as it were, begin his researches along any intermediate district as his convenience Or his sojourn for the time may direct. And thus, whether it be the gneiss of Cape Wrath or Ardtorinish — the granite of Aberdeen or Arran— -the schists of Kincardine or IT GEOLOGY OF SCOTLAND. the Mull of Cantyre — the sandstones of Stonehaven or Helensburgh — the porphyry of Dundee or Largs — the carboniferous deposits of St. Andrew's or Ayr — the columnar basalts of Earlsferry or Staffa — the lesson throughout will be one and the same, either as respects the mineral constituents, or the geognostic position, or the relati\e ages of the rocks examined. The causes of this parallelism in the mountain chains, and continuity in their rocky materials, are to be sought for in the elevatory movements which acted contempora- neously upon their masses, and the direction of the forces which produced them. The hypothesis of M. Elie de Beaumont implies that " continuous systems must have had a simultaneous origin," embracing a vast extent of geographical area, and arranged into groups and systems in lines parallel to a great circle on the sphere. The various qualities of rocks in Scotland are so arranged, from the most ancient primary to the newest sedimentary formations, running in a direction from south-west to north- east, and preserving throughout the valleys, slopes, and ridges of hilis one common line of bearing. As we shall afterwards see, volcanic agencies have been at work all over the island. These agencies lifted up the strata and formed them into mountains over their central nucleus. The great lines of tissnre, occasioned by the disruption of the strata, would consequently partake of the same rectilinear movements ; and hence the lakes, friths, and straths generally, as weU as the chains of hills and moun- tains, all maintain an approximation to parallelism — proofs that the upheaving agency from beneath must have extended across the country in the direction thus indicated. The mainland of Scotland lies between 54° 38' and 58° 40' 30" of north latitude, and 1° 46' and 6° 8' 30" of west longitude, and has been estimated at 26,400 square miles, and the circumference, including minor irregularities, at about 3000 miles. The islands and fresh-water lakes are reckoned to be nearly 3700 square miles, or upwards of one-ninth of its superficial area. The extent of coast- line from Duncansbay Head to Berwick is 713 miles ; from Duncansbay Head to Cape Wrath 145 miles; from Cape Wrath to the Mull of Galloway 1430 miles j the south coast where washed by the Solway to the mouth of the Esk 173 miles; and of borderland the distance eastward to Coldstream is about 90 miles. Hence there are rather less than eleven square miles of surface to one mile of sea-coast, whereas in the whole of Europe, there are twenty-five miles of surface to one of sea-coast ; and in the other quarters of the globe there is a still higher ratio of the former to the latter.* The rock formations of Scotland, now to be cursorily described within this area, consist of three great divisions, namely, the primary, transition, and secondary. To these are to be added a few limited sections of new red sandstone, and the upper and still newer series of strata of which two-thirds of the superficial extent of Englaud are covered, but of which only the smallest traces are to be found in Scotland along the north-eastern and western shores. Kocks are termed stratified or unstratified, aqueous or igneous, according as they have been sup- posed to be formed in water, or erupted in a melted state from the bowels of the earth. They are divided into formations, systems, and groups, according to the conditions under which they have been formed, and the mineral and organic contents by which they are distinguished. The term formation is applied to designate rocks which seem to have originated under nearly similar circumstances, and whose ages are relatively embraced within a definite geological epoch. The • Nicol's Guide to the Geology of Scotland, -^t^. 9, IQ, GEOLOGY OP SCOTLAND. t term system is of a more limited application, and is intended simply to express their relation to each other as determined by their mineral and fossil characters. A group of rocks is still less generic than either of these ; as there may be several systems in a formation, so there may be several groups in a system, such as a crystalline, sandstone, or limestone group or series of strata. The following table exhibits both divisions and sub-divivisions according to their mineral connexion, chronological order, and relative superposition. PBIMABT FORMATION. Gneiss. Mica Schist, Quartz Bock. Limestone. Ciay Slate. TABULAR VIEW OF ROCKS. TEANSITION OB lOWEB SECONDARV FOBMATION. Grauwake. Silurian Schists. Old Red Sandstone. Coal Series. Mountain Limestone. UPPER SECONDARY AND lERTIARI FORMATIONS. New Red Sandstone. Lias. Oolite. Wealden. Chalk. Tertiary Series. Granite. Basalt Claystone. IGNEOUS ROCKS. Felspar Porphyi-y. Compact Felspar. Greenstone. Amygdaloid. Clinkstone. Tufa. The rocks, as arranged under the head of formations, are all stratified, and are therefore supposed to owe their origin to deposition in water. The igneous rocks all belong to the unstratified class, and are consequently as justly ascribed to volcanic action, whose materials were once in a state of fusion, and ejected from beneath the crust of the earth. The primary series are by far the most widely developed of the rock formations of Scotland, covering upwards of 19,000 square miles, or about two-thirds of its superficial extent. They prevail chiefly in the northern Highland counties. The lower group of the secondary formation is, in part of the series, limited to the southern division a.ad border districts, consisting of grauwake, silurian schists, and impure shelly limestones. The middle or central districts are occupied with the old red sand- stone, the coal metals, and the mountain limestone. The upper secondary and tertiary formations are, in Scotland, of very limited extent, and chiefly confined to Dumfriesshire and the Hebrides ; while again, with the exception of the granite the igneous class all lie within the area of the coal field or form its out- works, consti- tuting the Sidlaw, Ochil, Campsie, Kilpatrick, and Pentland ranges of hills. But in proceeding with our geological description, according to the natural order of the rocks from the lower to the higher, it will be most convenient to adopt their geographical distribution from north to south, v/hieh arrangement, although neces- sarily attended vdth some repetition, will upon the whole be found the most con- ducive to perspicuity and systematic condensation. One of the most remarkable facts in descriptive Geology is, that in a transverse section from any two points across the mainland, as from Cape Wrath to Berwick, we pass over the whole intermediate series of rocks— system upon system — not piled up in one colossal mass, but drawn out and slipped over the edges of one another, and so arranged and disposed at successive intervals, as to be projected in regular order to the surface. The arrangement, like the drawers in a cabinet or the courses in a building, is thus uniform from below upwards, and as nearly as possible according vi GEOLOGY OF SCOTLAND. to lineal perspective. This arrangement is never inverted. From the blue slates of the Grampians to the new red sandstone flags of Dumfriesshire, there is a persistent succession of ascending beds of rock, lying with their outcrops one above another, chapter after chapter of the world's history stereotyped on their stony tablets, and the families of its remotest annals in countless numbers of vegetable and animal forms restored to the inspection of the curious, learned and unlearned. The aimexed section gives a condensed view of the different formations, in their natural order of superposition and geographical sequence ; from the Grampians to the Solway, in which, according to their several systems and groups, the whole series of Scottish rocks are represented from the granite to the new red sandstone (see Plate I). A section froni the same primary range, taken in a northern direction to the Pentland Frith, includes the same series, with the exception of the coal measures ; but in their stead, there are patches at irregular distances of the over- lying formations, as the oolite, wealden, chalk, and tertiaries, so abundant in England. Thus, within the circumscribed limits assigned for this sketch, rocks of every known kind meet our view, and Scotland in its mineral wealth and variety may be considered as an epitome of the globe. THE PRIMARY FORMATION. The rocks included under this formation consist of granite, gneiss, mica-slate, liinestone, quartz-rock, and clay-slate. Their mineral constituents differ very little from each other : felspar, quartz, mica, and hornblende, enter into them all ; lime, talc, and chlorite, are more abundant in or exclusively confined to others; and, through the whole series, these simple minerals exist either in the form of perfect crystals, or as broken, fragmentary portions of crystals. They are all, in conse- quence, more or less, crystalline in their structure ; and they are termed primary, because they not merely denote the absence, but are assumed to have been formed before the existence of living things, vegetable or animal. Granite constitutes the basis of the whole; and although, according to the igneous theory of its origin, it is probably a later formation than any of them, yet as the fundamental rock, not only in this, but in all countries of the world, it falls naturally to be described as the first of the series. The prevailing constituents of granite are quartz, felspar, and mica; where hornblende is added or substituted, as it frequently is, for mica, it is then denominated sienite ; and in this form it is easily distinguished by the darker colour which it assumes from the presence of the hornblende. The more usual colours of granite (which are red, grey, or whitish grey), are not unimportant as regards its texture for polishing and economic pur- poses. Thus the red of Peterhead and Aberdeen are found to be the most durable • the white varieties are esteemed to be the next in quality : the scale of hardness diminishes in the proportion in which hornblende, talc, and other ingredients abound. The mica sparkles like gold, and exists sometimes in crystals as weU as the talc, of more than a foot square, when it is split up into thin plates, and used as a substitute for glass. Some granites are binary, consisting only of two minerals, felspar with quartz or hornblende, and when polished break into irregular lines resembhng Arabic letters, on which-account it has been called graphic granite! A vem of this rock traverses the district about a mile east of the town of Port soy, in Banffshire, in connection with mica-slate and a bed of lustrous maxble of great celebrity. GEOLOGY OF SCOTLAND. Vii Nothing surprises one more -wten looking at this brilliantly diversified rock than to he told that it owes its origin to fire, and once existed in a state of fusion beneath the crust. Granite forms mountains, always the largest in volume and loftiest in elevation in the world. It environs with its rocky vesture the whole circle of the globe, and is the basis on which all the other formations rest. It has penetrated and risen above every other part of the crust, and, in beauty of colouring, closeness of texture, condensation, and other qualities of endurance, granite, even in the mass, resembles, if it does not sometimes rival, the gems and precious stones of rarer occurrence. What the precise combi- nation of causes, and what the circumstances under which they must have acted, in order to unite the ingredients in the proportions and forms that constitute its peculiarities, there are no means, in the present state of science, of deter- mining; but by a common observer examining a hand specimen of this remarkable rock, the agency of heat would least of all be predicated as having been concerned in its production. It is difficult still more, upon many scientific grounds, to admit the hypothesis, as, for example, the unequal fusibility of its general constituents, quartz, felspar, and mica; — quartz requires for its fusion a temperature equal to 4043° of Wedgewood's pyrometer ; felspar is fusible at a varying heat of 120° to 150", and mica can be reduced at a still lower temperature. It is argued, in these circumstances, that the tripartite crystalline structure of this rock could not be effected — that in the same mass quartz could not be fluid when felspar was solid — nor the mica in a condition to be aggregated with either — when all, if in fusion must have been consolidated at such unequal temperatures. It is farther argued, that, as regular crystals of felspar are not unfrequently found imbedded in quartz, the felspar must have become solid while the quartz remained fluid, contrary to what would have happened from the known fusibilities of these substances^ if they had consolidated from fusion. Asbestus, it is likewise stated, is a foreign ingredient in granite, and which, although it melts at a lower temperature, is found penetrating in the most delicate fibres through the quartz ; and, finally, that shorl, a substance of comparatively easy fusibility, is often crystallised in the quartz, shooting through it in every direction, with various wavings and incimra- tions, and in fibres even finer than the human hair, all tending to prove that the quartz had been completely liquid when the shorl crystallised. Whence, above all, it is demanded, the source of the immense heat, the causes of its support, and the means of its action when deprived of the vital air, that could first fuse masses of matter beyond the power of imagination to conceive, elevate these masses through the crust of the globe, and pile them up into the highest mountain chains, simultaneously in the several quarters of the globe ? * It is argued, in reply, that the fires that issue from volcanoes are evidences of heat existing in the interior of the earth; and that, in a globe of eight thousand miles diameter, there are stores enough of the combustible element for the fusion of matter elevated only four or five miles on its surface. The craters of Etna and Vesuvius have been successively augmented, and islands are fre- quently seen to arise out of the sea ; and what, therefore, could hinder the forces that raised up the Alps, Ilymalayas, and Andes, from melting and ejecting the materials of which they are composed? The state of extreme condensation in which the granite rocks are found to exist shows the presence of some cementing • Comparative VietO of the Huttonian and Neptunian Systems, pp. 240-1. Tiii GEOLOGY OP SCOTLAND. element, in the aggregation of their component particles, which heat only 1733 capable of producing. The several crystals are likewise in such a condition of form, arrangement, and contact, as only fusion could have rendered possible; as, for example, when they impress each other, quartz moulded on the felspar, or, as no less frequently happens, the felspar giving its form to the quartz : a clear evidence, in either case, of a soft condition of both substances, and that softness occasioned by fusion from heat. The existence of veins so generally diffused among the primary rocks, and composed of the purest specimens of crystallised granite, is adduced as one of the strongest proofs of the igneous theory of its origin. These veins have the appearance of streams, of the melted substance, that have poured through fissures and rents, penetrated and broken up passages in other rocks, run- ning in every direction, and often crossing each other, and generally traceable to some great nucleus or central mass of the formation. The rocks along their course are usually altered, or affected in such a manner by induration, discolouring, frac- ture, or smoothness of surface, as indicates either the presence of intense heat, or the mechanical action of a body of matter violently intruded amongst them. Lastly, the form and position of the primary mountains, the dislocation and upheaval of their exterior parts, where strata originally horizontal are now nearly vertical, and beds once united are separated, and the interspaces filled with granite, are regarded as the most direct and conclusive testimony that the disturbing agency has been produced by the expansive force of heat, and that the intruded matter, which is silways granite,^has been fused and ejected by its action.* These are some of the arguments adduced on both sides of the celebrated con- troversy known as the Wernerian and Huttonian Theories, whereby the one ascribed the origin of all rocks to precipitation in water, whUe the other con- tended that granite at least, and some others, were produced by fusion in fire, and ejected from the interior of the earth. Hence the terms Neptunian and Plutonic rocks as applied to their respective systems. Werner, the father of systematic mineralogy, studied in Germany, and derived his knowledge chiefly from the Hartz and Swiss mountains. Hutton was a native of Scotland, traversed all the hills of Caledonia, and founded his theory mainly on the appearances of granitic veins as exhibited in Glentilt, the centre of the Scottish Grampians. Though little doubtful of the cor- rectness of Button's views. Sir Charles Lyell applies the term hypogetie to the granitoid group; that is, nether or under-formed rocks, to avoid any particular theory as to their origin. But the term has not been generally sanctioned among geologists, the prevailing opinion being that granite is of igneous origin, the result of the gradual cooling down of the globe while in an incandescent state, and is therefore inferior to all the stratified systems. The Grampian range, which divides Scotland into two nearly equal parts, and separates the Highlands from the Lowlands, is the principal seat of the primary formation, and of which granite constitutes the centre or nucleus through their entire length. The great mass, forming the anticlinal axis of the district, stretches from the western shores at Oban, to Peterhead on the eastern, where some of the loftiest peaks of the Grampians consist of granite, rising in Ben Cruachan Ben-y-gloe, Ben-Mac-Dhui, Loch-na-gar, and other distinguished mountains, to upwards of 4000 feet. Ben-Mac-Dhui, according to the latest measurement, is 4418 feet in height, and covers a superficial basis of nearly forty miles in extent • Piayfair's Illustrations of the Huttonian Theory. GEOLOGY OF SCOTLAND. ix one vast mass of reddish granite. It occupies a central position in the loftiest part of the range, in whose deep recesses are the sources of the Dee and Don, and the springs of the "deer-haunted Avon," whence ridges of granite diverge for thirty miles continuously in every direction, and extend over the whole eastern division of Aberdeenshire. A vast, but less connected range, traverses the district from Morven, on the west, to the Moray Frith, on the east, passing through Ben Nevis, Glen Roy, the mountainous shores of Loch Ness, and sending outliers along the Find- horn, to Forres, on the south, and on the north by Loch Eil, Sunart, Loch Duich, and the wild districts of Kintail. Detached mountains of great elevation, and long out -stretching hillocks in the moorland districts, occur in Ross, Sutherland, and Caithness; the islands of Sky, Rum, Mull, and Arran, are all caped in their highest pinnacles by the same rock, whence it stretches, but at wide intervals, into Kircudbrightshire, through part of Wighton, Galloway, and terminates in the lofty table-land and ridge of Criffel, on the Sol way. Over this wide extent of its superficial distribution granite, according to the most accurate estimates, covers about 1760 square geographical miles, or about a fifteenth part of Scot- land; but, considered as an eruptive or hypogene rock, the formation may be found underneath in many localities where it is not actually visible. While, in Goatfell, and other mountain peaks, the granite protrudes through the schistose rocks that wind round their bases and sides, and often cover them to near the summits, there are many other mountains, as Ben-y-gloe, and Bernera, near Fort Augustus, where the formation is only discoverable by small out-bursts that are exposed in the ravines worn by the rivers along their acclivities, or by veins traversing the strata in their immediate vicinity. The veins themselves form an interesting feature in the geological history of the primary rocks. The granite veias are of different dimensions, some being of the breadth of several yards, others of a few feet or inches, and some even as thin as paper. They are of unknown depth, and generally diminish in thickness as they recede from the central mass or main body of the formation. Veins also occur in many places where there is no visible connection with the parent rock, and where, for miles distant, no granite mountain appears. The presumption is, from what are actually seen, and the curious and diversified ways in which the overlying systems are penetrated, that, were the surface of the primary districts fully exposed, these remarkable phenomena would be found over the length and breadth of the country, reticulating every part as with a gigantic system of network, and showing the mighty levers employed by nature in piling up her Cyclopean masonry. They are found in most of the western islands, and in some of them, as Coll, where there is no connection with any mass of the same rock. In Arran they are beautifully developed, in Glen Rosa and Glen S annex, also in Glen Catcol, where they pentrate in every direction, and in every degree of thickness, the clay and mica slates : in Galloway, on the banks of Loch Kin, where an interesting series occurs, varying from fifty yards to the tenth of an inch in width, and running through the schistose beds, over an area of country of nearly eight miles square. The veins in Glentilt are seen in the bed of the river, where, in the space of little more than a mile, the strata of limestone are intersected by nine or ten large, and by double the number of smaller veins, some extremely thin, and several of them, accompanied with such marks of dislocation, confusion, and induration in the invaded rocks, as indicate very strongly the original fluidity pf the granite, and the violence with which it has been injected amongst them. c a GEOLOGY OF SCOTLAND. They are likewise observable in several places in the district of Rannoch, at Glen-Drummond on the Spey^ at Fort Augustus near Loch Clonei, in the neigh- bourhood of Huntly, and about eighteen miles northward, ait Portsoy, where the singular graphic variety of granite is found. Veins are equally numerous in the counties of Ross, Caitnness, and Sutherland; and here, in closing our description of them, we would particularly notice the promontory of Cape Wrath, " the land's end of Scotland's wildest region, and the most advanced jpost of its wildest seas." This majestic promontory rises about 600 feet above the sea— a bare, rugged, flinty mass of stone, and is connected with the mainland by a ledge of rocks, consisting of gneiss and quartz ; the cape itself is composed of gneiss, interstratified with dark hornblende rocks, and reticulated all over witji the most remarkable display of granitic veins. It is hollowed out into lofty arches and winding caverns, through which the sea passes with the velocity of a torrent ; a huge pyramid, towering above the loftiest billows, and presenting, as the termination 'of the rude mountain ranges of Scotland, a buttress of unriyalled strength and sublimity, worthy of all their wildness and all their grandeur. The rock which immediately overlies the granite is Gneiss, of which there are three varieties, each composed of felspar, quartz, and mica^ and only distinguishable by the size, form, and arrangement of the crystals that constitute the mass. Gneiss is essentially, therefore, a granite in its component .parts, but differs from granite in being always stratified,; and in presenting none of the phenomena that accompany the agency of fire. It is indisputably admitted toj he Of aqueous origin, formed by precipitation iu' water, and afterwards indurated by chemical action or mechanical pressure. It consists of a series of thiii lenticular plates, which give it a ribbon-like appearance, and which, according to. the predominance ;of one of the ingredients, causes the rock to assume the sla;ty, granular, or aggregate structure. Talc, hornblende, chlorite, actinolite, as -in granite, are not unfrequently diffused through the substance of gneiss, whence particular names have been adopted to distinguish the varieties in which they occur. T.hus, when talc or chlorite is mixed in the substance, it is termed protogine, by the French geologists ; when the crystals of felspar and quartz are very minute, the rock is named whitestone, ovleptinite; when the hornblende and felspar .predominate, mixed with actinolite, it graduates into a primitive greenstone ; and -when -the quartz and felspar are scarcely visible from their extreme attenuation, it merges, into , a variety of hornstone. Sometimes the quartz, instead of being disposed in layers or plates, in the felspar, occurs in small parallel rods or bars; and when this species is cut perpendicular to, the direction of the rods, especially after exposure to the atmosphere, it assumes the appearance, and in hand specimens is often mistaken for, petrified wood. Gneiss, the lowest; of the stratified rocks, is likewise the most widely diffused of the Scottish primary series, filling an area of 9600 square miles, and with scarcely a break over this extensive district of country. It occupies nearly the entire northern counties of Sutherland, Ross, and- Inverness ; great part of Nairn Elgin, Aberdeen, and Perth shires ; most of the western islands, as Tiree, Coll, South and North Uist, Harries, and Lewis, consist of the formation, as also con- siderable tracts in Orkney and Shetland. . "While in a soft state, or from the vast pressure to which it has been subjected, this ro.ek often assumes the most singular contorted appearances^ whole miles presenting tvristings and undulations as if the substance had been moved and tossed ' like a stormy sea, and sometimes crumpled aud bent, or rolled into gentle, unbroken flexures like a web of cloth. It will thus GEOLOGY OF SCOTLAND. xi in such cases, exhibit beautiful and picturesque aspects; and where exposed in ravines along with other rocks, with which it finely contrasts, no better pictures or groupings of rock scenery are to be met with. But, ia general, where the gneiss is unbroken, and as it seldom rises into peaks or serrated ridges, the districts in which it prevails are rather monotonous and unpleasing, not unfrequently dis- figured by spongy heaths and boggy wastes. The most desolate, uninteresting portion of the Highlands is unquestionably the north-western districts of Ross and Sutherland, where the hills of this formation are all fiat and shapeless, surrounded by unvarying solitudes of brown moor, interminable deserts of sand, and scarcely enlivened by a river, or broken in their silence by a waterfall. Gneiss is the oldest rock known in the records of Geology — the lowest floor of the most ancient seas — probably the first dry land that rose above the'r surface — and here in these sterile wastes presenting a scene of almost primitive chaos and desolation. The next member of the series, in the ascending order, is Mica-Slate, or Schist, which, eis possessing more mica, and being of a more slaty structure, is so denominated. This rock is readily distinguished from gneiss by its glistening aspect, and from granite by the absence of felspar, although it occasionally seems to graduate into both when in contact. The particles of which it is composed are uniformly more broken and rounded than those of gneiss, which probably arises from their being partly derived from the granite and partly from the gneiss, and have in con- sequence undergone a double process of attrition. Veins of quartz, parallel with the strata or crossing them in every direction, are so predominant often as to change the usual colour from a glistening grey into a mottled white. Vertical dykes of the purest quartz, sometimes several yards in breadth, and traceable for mUes along the surface, are likewise of frequent occurrence. One variety is termed garnet-schist, from the circumstance of these beautiful crystals being so abundantly distributed through the substance of the rock as to form a principal ingredient, as well as greatly to enhance the sparkling lustre of the mica. The garnets vary from the size of a small seed to an inch in diameter, are of a dark crimson colour or blackish brown, and under a bright sun look like gems in a setting of gold. They occur plentifully in the formation near Huntly, in the upper districts of Strath Tay, and of considerable dimension and very perfect in the Isle of Mull. The geographical distribution of this • rock is much inferior in extent to the gneiss : it is chiefly confined to the more central division of the Grampians, which it accompanies in one continuous envelope, along the range from sea to sea. The mica-schist thus embraces within its course the finest and most celebrated scenery of the Highlands. No lover of the picturesque, in his most favoured haunts, can fail to recognise it, whether by its bright metallic aspect or the remarkable flexures into which the strata are twisted and folded up. Suffice it to mention the beautiful ravines on the Esk and Isla, the pass of Killicrankie, the Trosachs, the charming environs of Loch Ketterin and Loch Lomond, the pre- cipitous defiles of Glencoe, and the dark rugged mountains that surround Loch Goyle, Loch Fyne, and Loch Awe. The hills of this formation are among the loftiest and most notable in the Grampian range, rising to 4000 feet and upwards as Cairnwell, Ben^y-gloe, Schiehallion, Ben Lawers, Ben Vorlich, Ben Led', .Ri/ Venue, Ben Lomond, and all the bold serrated ridges to the west. The Ioj^ np.aa, land terminating in the Mull of Cantyre, great part of the islands of Ei?.le, Aviaj\ Jura, Isla, and the whole of Colonsay, consist of mica-slate ; whence 'r j.^siug to tht. rii GEOLOGY OP SCOTLAJSTD. mainlancl, embracing Mull, the formation stretches from Appin through Glencoe, encircles Bea Nevis and the higher parts of Badenoch, lines the watershed of the Spey on both sides as far as Laggan, where it is interrupted by the gneiss, but re- appears on the slopes of the Cairngorm mountains, and spreads over great part of the intermediate district towards Portsoy and Cullen. We have remarked on the veins and dykes of quartz that characterise the mica-slate formation, and no one perhaps ever passes a bowlder of this substance without a momentary inquiry as to the causes of its origin, or the pure region whence it has issued. The student in Geology is familiar with mountains of it. Quartz-bock exists as an independent member of the series, as well as an ingre- dient in every one of the primary, and of nearly all other rocks. One set of theorists regard it as oaly an altered sandstone, which, through the intense action of heat, has been fused, and on cooling was crystallised. The more prevailing opinion is that which ascribes it, like gneiss and mica-schist, to precipitation in water; but as it alternates with both, sometimes resting on the granite, some- times intermediate betwixt the gneiss and schist, not unfrequently overlying the latter, and plentifully distributed through them all, in the form of veins and dyke?, which penetrate, like the granite itself, the whole members of the system, it is difficult to ascribe to either view, and still more diiScult to find a substitute for either theory of formation. There are problems in every subject which science has not yet solved. That there should be mysteries in Geology on the formative processes of rocks, the sources of their constituent elements, and their mode of aggregation, is according to the rule and not the exception of speculative inquiry. The quartz- rock, thus difficult in theory to be accounted for, has a range and position in the Grampians nearly co-extensive with the mica-slate, with whose substance it is so mixed up and forms so large a proportion. A belt of quartz crosses the island, having its eastern limit in Banffshire, its greatest breadth in Braemar and Athole, and attaining its culminating point on Schiehallion, which consists wholly in the upper ridges of pure granular quartz. The line of bearing is by Glenlyon and Glenorchay, where it terminates near Dalmally. The islands of Lismore, Lunga, Scarba, Isla, and Jura, are almost composed of quartz-rock, attaining in the Paps of Jura an elevation of upwards of 2000 feet, whose summits glance like polished marble under the rays of the setting sun, the Pharos of the western main. Another band of the same formation traverses the north-western coast from Loch Eishort in Sky, to Loch Eribol on the mainland ; here there are several quartzose ridges of considerable altitude, among which is the Stack Balloch-nan-fey, a large conical mass of pure uncovered quartz-rock, described by Pennant as marble, and which glistens in the distance like snow. Ben Lair, Ben More, and other mountains in Eoss-shire, of first-class magnitude, are composed of the same siliceous substance; likewise, the range of the Scarabins, on the southern verge of Caithness-shire, whose whiteness beautifully contrasts with the deep red of the sandstone by which they are encircled. Ben Lair exceeds 3000 feet, on which, says Dr. M'Culloeh " though it produces few Alpine plants to regale a botanist, a mineralogist will find enough employment in collecting the greatest variety of quartz that is perhaps to be found in any one place in the world, ranging from jet black, through every possible gradation to snow white, and equally differing in texture and appearance. But its great attractions are the views from the summit, and chiefly to the north- ward. The eye wanders far over the wildest mountains of Ross-shire, and throuo-h a county as apparently uuinhabitaDk as it is uninhabited. It is ususl, in describing GEOLOGY OF SCOTLAND. xiii mountain sceneryj to speak of rocks and precipices, ■whether present or not, hut here they exist without any need of exaggeration. There is the reality in this district, not merely the name : mountains, whose faces show the very skeleton of the earth in all the details of its stratification, for miles together; with deep and wide valleys of enormous dimensions, hounded by vertical acclivities, just as the little ravines of torrents are in other places; everything is gigantic and terrible; wild and strange and new. From the summit of this mountain, the eye sees at once down into a valley, as if perpendicularly beneath, and at a depth of at least 3000 feet ; while the various precipices that rise all round, no less than those which start imme- diately from beneath the feet, tending downwards into the abyss, and the deception which makes us imagine that even ourselves are suspended above it. Numerous lakes, among which Loch Puir is conspicuous, add to the beauty of this wild and wondrous scenery ; increasing also the picturesque effect produced by the infinite variety and intricacy of the mountain forms, by the deep shadows of the valleys, the reflected tints on the mountains, and the innumerable atmospheric effects in which scenery of this class always abounds." While the eye of the geologist is thus enchanted, and the imagination regaled, amidst these sights and scenes of his apparently dry vocation, it is his province also to relate that, in an economic view, the quartz formation is neither the most valuable nor ornamental of minerals,— that for architectural purposes it is unsus- ceptible of pohsh, and to the agriculturist can be of no use, — and that, whisrever it prevails, its course is marked by one continuous tract of sterility and barrenness, of spongy heaths and rocky debris. But nature, who scatters her good things on the right hand and on the left, is sometimes as exuberant in her bountifulness as she is niggard and sterile in other communications. The rock which succeeds the quartz, and sometimes alter- nates with it, or is enclosed in its beds, is the primaky limestone or marble, so extensively used for ornamental purposes. This formation consists of nearly equal parts of lime and carbonic acid, with a trace of silica. It resembles the quartz in outward appearance, in being granular, white, and lustrous in colour, and regularly stratified, and in hardness is scarcely distinguishable ; but how different in its susceptibility of polish, and other practical uses. Famed among the ancients in the celebrated quarries of Paros, Pentelicus, and Carrara, their finest and most enduring specimens of sculpture were chiselled from the same family of rocks which claim a parentage with the limestone of the Grampians. There are several varieties, differing chiefly in colour, fineness of texture, or as containing imbedded crystals ot tremolite, sahlite, augite, asbestus, and steatite, whence it derives its unctuous feel and variegated colours, as mottled, striped, and veined by lines of pink, green, and yellow. Its range is nearly co-extensive with that of the quartz formation, being generally imbedded in its mass, or accompanying its outcrop. It is burnt in a great many places into quicklime, but as the concretions have an extreme tendency to exfoliate and separate during the process, by the volatilisation of the carbonic acid, it is difficult to preserve its cohesive and other chemical properties, and is accordingly not rendered so applicable to economic uses as it otherwise might be, from the large proportion of calcareous matter contained in it. Preserving the same line of bearing with the quartz-rock, this limestone stretches along the more central parts of the Grampians, and is found in almost every position— in the bottoms of valleys, in the beds of rivers, on the sloping acclivities of moimtains, or even caping their ridges and summits. It occurs plentifully on both sides of the xiv GEOLOGY OF SCOTLAND. Dee, from Ballater towards the Castletown of Bracmar, at which latter place it nearly composes the beautiful hill called the Lion's Face, and thence passes west- ward by Glen Clunie and the base of the quartz -caped Morven. Appearing at several intervening localities, it descends Glentilt, where it is so frequently pene- trated by the granitic veins of Ben-y-gloe ; and, crossing the river Garry, it may be observed high on the sides of the green hill of TuUoch ; and spreading over the extensive tract southwards, to Loch Earn, there are various openings in the strata for quarries— in Glen Tummel, Glenlyon, near Loch Earn head, at Aberfoyle, Auchmar, Loch Lomond — when it is again traceable through all the western isles, from Lismore to the more quartzy regions of Jura and Isla. The Clay-slate forms a very narrow strip, of about five or six miles in breadth, and may be described as the outer envelope of the primary series and upper crust of the Grampian range. It extends from Stonehaven, in a continuous belt, to Eoseneath, and through Bute to Arran, where, at Loch Eansa, it is penetrated by the granite, and is seen in connection with the mica-slate. It consists of a fine- grained argillaceous basis, of considerable hardness, of various colours, from a greenish-black to a deep-mottled purple, arid, from its splintery fissile structure, is admirably adapted for roofing-slate. Some of the smaller islands in the vicinity of Oban, as Luing, Eisdill, and Seil, are entirely composed of the formation, where it is extensively quarried, and has long formed an article of export. Various other bands of slate occur, in groups of diflferent kinds and qualities, among the primary mountains. They are confined to no particular mineralogical district, but are lis- tributed at long intervals, and appear as outliers indiscriminately in the granite, gneiss, and mica-slate series. They are termed talc, chlorite, actinolite, and horn- blende schists, according to the prevalence of any one of these mineral substances in the mass. They have less or more an unctuous feel, a foliated or fibrous structure, an extremely flexible texture, and a fine glossy lustre. The chlorite schist is very abundant in the Cairnwell and Glenshee group ; the hornblende variety, also strongly impregnated with cubical iron pyrites, occurs at Ballahulish and Appin, and Ben Lair, in Ross-shire ; talc-slate is not abundant, and is generally incorporated with the mica-slate, by the substitution of the talc for the mica plates. Actinolite schist is usually associated with, as it differs little in character from, gneiss and some specimens of granite, and is found in considerable quantity in Glenelg, and the high and beautifully sloping passes of Glen Shiel. The rocks of the primary formation, now described, are represented in Plate I., section 2, where the granite, as figure 1, occupies the centre of the group. The rest follow in the order enumerated — 2, 3, 4, 5, 6 ; but, of course, on so small a scale, the subdivisions, dislocations, veins, and intersections, are not exhibited. The remaining figures point out the formations yet to be described, according to their ascending order of superposition, and as far as they lie within the assumed line of section. After this brief description of the different members of the primary rocks it only remains to be noticed, in connection with the prevailing theory of their forma- tion, and the law which seems to have influenced their mode of ao-gren-ation that in proportion to their relative distances from the fundamental granite, the gi'eatcr is the comminution of their particles, and the less crystalline their structure. Assuming the igneous origin of granite, and it necessarily follows that its surface, penetrating the waters of the primitive seas, would be subject to the disintegrating influence of atmospheric, aqueous, and chemical agencies. The waters themselves, especially GEOLOGY OP SCOTLAND. xr those resting in the ne'wly-formed hollows, must have heen heated to a high degree, the air loaded with vapours, and the superficies of the earth raised to a compara- tively high temperature. The process of disintegration would consequently be much accelerated. The runnels and streams would carry down the loose particles, dis- posing the heavier first and nearest, and carrying out the lighter and smaller to deeper basins. And thus the whole system of the schistose rocks, in the primary series, might have been forming at nearly one and the same time, or within a compara- tively limited period of each other. The garnet-schist demonstrates of itself a very high temperature over the surface of the globe, as the garnets and other crystals denote that the rocks in which they are imbedded have experienced a degree of heat sufficient to form such fusible minerals without being able to melt the other con- stituents of which they are composed. The hard crystalline texture of the primary rocks, and the total absence of organic remains, also strongly warrant the inference that they have been exposed to the action of heat after the deposition and arrangement of their strata. Hence, there exists the greatest affinity often betwixt these rocks, where the granite is fused into the gneiss, the gneiss into the mica-schist, and the quartz-rock, marble, and alternating beds all welded, as it were, to each other. Heat alone, of all known causes, could produce such results. Added to the pheno- mena of veins, the effects of the after-fusion of the granite, the changes, dislo- cation, and induration invariably produced upon the strata through which they penetrate ; and there are few dogmas of science that can boast of resting upon a stronger induction of facts, than that the mountains of the earth owe their elevation to the expansive force of internal fire, and that its massive foundations have been mainly consolidated through the instrumentality of the same agent. The rudiments of all other rocks, and of all after formations, are likewise there, re-compounded only from the waste and debris of the originally solid parts, or cast out from beneath them by the influence of the causes by which they were upraised. The quartz of the granite constitutes the substance of some of the more precious gems ; the mica is divisible into plates of the l-300,000th part of an inch in thickness, and enters as an ingredient into almost every combination of matter ; the felspar is reduced to clay, and mixed with the hornblende forms the soil of our most fertile carses. Here, also, among these rocks, wherever existing on the globe, is the vein of the silver, and the gold, and all the rare metals ; the emerald, sapphire, beryl, topaz, and amethyst are all derived from their interior. The marble to decorate our houses, and the slates to furnish a commodious roofing, are among the first of nature's ofiFerings ; and thus combining security and elegance, usefulness and beauty, variety and richness, the foundations of our steadfast earth, and the arrangement of its mineral substances, are well calculated to speak the praises of its munificent creator and to form a noble subject of contemplation to its intelligent inhabitantSi THE SILURIAN SYSTEM. The vast masses of crystalline rock considered above constitute, as far as the researches of Geology can determine, the original crust and dry land of the solid ter- raqueous globe. The mandate for producing life upon its surface was not issued when the matter of these rocks was being arranged and consolidated. Not a par- ticle of any organised substance has been detected in any part, through all their profound depths, of the primary formation. But the whole, the entire aggregate of material substance created, arranged, and upheaved to the influences of sun, light. XTi GEOLOGY OF SCOTLAND. and air, the living order and series of events commenced, and of which in the rocks of the Silurian System there are the first intimations. Herein are contained, if we may so speak, the medal-stamps of creation in the earliest forms of organic life that came from the hands of the Creator. The fact is all-important, and the science is enabled to announce it, that in the lowest fossihferous rocks vegetables appear to have been the first of all organic bodies — the impressions of plants and beds of carbonaceous matter are found in the deepest and oldest strata of the formation ; and no less satisfactory is the discovery that the fossils which next arrest the atten- tion, and, embalmed in their stony matrix with the vegetables, are the remains of marine animals, myriads of shells, and vast numbers of fishes — creatures all of the deep, when the command had been given, " Let the waters bring forth abundantly the moving creature that hath life." The geologist at once here plants his foot on holy ground, and rejoices in results that so strikingly harmonise all his speculations with the record of divine truth. These are legends of very olden times. The rocks Tm.der consideration contain them in their brightest and most legible characters. The rocks of the Silurian formation have been divided into three systems or groups — the transition, grauwake, and Silurian proper. They are all stratified, and in their component parts are more or less siliceous and crystalline, arenaceous, argillaceous, and calcareous, in which there are alternating bands of slate, sand- stone, and limestone. The term " transition" has been applied to a part of the system as not only indicating a change in the causes and conditions of their formation, but as implying that the world was then advancing from an uninhabitable to an in- habitable state. The " grauwake" is simply the German term for grey-rock, and is applied to the more coarsely granular portion of the series. Professor Sedgwick designates these and other beds as the Cambrian group, because they constitute a large part of the surface of ancient Cambria or Wales. The upper members of the series are called Silurian, as occupying the country of the Silures, an ancient people who dwelt in the district lying betwixt England and Wales, where these rocks, consisting of various groups are largely developed. The division into Cambrian and Silurian is not generally admitted by geologists, the latter designation being held as applicable to the whole, while the term transition is scarcely now theoretically necessary or admissible, since the distinction is so clearly drawn between the fossiliferous and the non-fossiliferous formations. The system is in many places upwards of 30,000 feet thick, embracing an innumerable series of strata, and all containing fossils. The clay-slate occupies an intermediate territory between the primary and transition systems, being sometimes classified with the fossiliferous and sometimes with the non-fossiliferous rocks ; but, as in the Grampian range no organic remains have been detected in any part of this widely extended system, we have noticed it in connection with the more ancient series, which thus constitute one great physical group, existing in the same physical region, and formed and elevated under the same physical causes. Nor have any true Silurian strata been yet established to ■ exist in this district, overlying and outward the clay-slate. The great valley of Strathmore, the slopes and defiles of the Sidlaws and Ochils, are occupied with rocks lithologically as well as organically distinct, and all belonging to a higher series and a later epoch in the earth's history. Still such arguments as the follow- ing may be advanced in support of a Silurian connection with the clay-slates of the Grampians. First, this band of slate resembles in texture and colour the slates of Cumber- GfEOLOGY OF SCOTLA^T). xvii land and "Westmoreland, in hand specimens scarcely distingnistablej and often less crvstaUine tlian the bands overlying the dark chloritic slates of Skiddaw. The position of the clay-slate in reference to the trae primary series, in the next place, is very distinct, never alternating -with, nor lying conformable to, any of these rocks. It forms the onter zone of the Grampian range Tvhere porphyritic and trappean rocks are abundant, often interposed and associated with the slates sometimes reversing their dip, and at other times rendering them almost comtbrmable to the mica- schist. Moreover, immediately overlyini: the clay-slate, precisely as in Cumberland and else- where, the old red sandstone rests unconformably ; near Dunkeld, and eastward by Blairgowrie, as well as flanking Bimam bill on the sonth-ivest, the grauwake charac- ters are strongly presented in some of the ridges. A single organism would determine the point, as yet undetected in the numerous openings and quarries along the line of deposit. But the absence of organic remains has been attempted to be partly accounted for by the fact of the vast disturbance prevailing in the seas during the deposition and upheaval of the strata, and indicated by the enormous mass of igneous matter spread over their bottom, and repeatedly intermixed with the bands of slate. The student of Geology, however, has ample scope for examining this system of rocks, so interesting as shadowing the fii-st dawn of life upon the earth, in the Lam- mermuir range, where they are developpd upon a large scale. Though not so extensive and lofty as the Grampians, this group of mountains combines many of the boldest features of Alpine scenery, and are well entitled to be denominated the Southern Highlands of Scotland. The axis of the chain runs from E.2S.E. to TT.S.W., and extends nearly 150 mUes in length, by an average breadth of thiity to forty miles. It consists of various groups of hiUs, divided at intervals by rivers and their divergent valleys, and forms the frontier barrier, from St. Abb's Head in Berwickshire to Port Patrick in TTigTonshire. The Lammermuir, Mooitoot, Hart Fell, Lowthers, and Queensberry, constitute the more elevated portions of the range. On the eastern extremity, where it terminates on the coast, the solid strata are singularly contorted, forming several convolutions, and bent round an axis of curvature parallel to the chain. Similar contortions and twistings are beau- tiftdly exposed near Langholm, and in several places in Upper Eskdale. As a general characteristic of the formation, it may be observed, that all the beds in the southern portion of the range are finer grained than those in the northern, more fissile and slaty, and Me at a considerably lower angle of elevation. The gigantic piles around Peebles and Motfat are, many of them, of a flinty or sub-crystalline texture, and tilted nearly perpendicular across their line of stratification. The igneous rocks constitute at Innerleithen a marked and interesting feature, where the trap assumes a granitic structure, and the grauwake at the points of jimction is converted into Lydian-stone. This rock is often a mere siliceous variety of day- stone, hardened by the intruding igneous matter into a consistency so as to strike fire with steel. It is of a light grey or bluish colour, sometimes of a deep black aspect, when it has been mistaken for coal, and fruitless attempts made to reach the inner beds of the valuable combustible. Alum-slate is likewise found in a few places, but in small amount. These beds are generally very soft and friable, of a saline taste, and readily distinguishable bv a white efflorescent powder on their exposed surface. The linra of cleavage are very distinctly marked in all the varieties, and they are always at right angles to the bed of stratification. Fissures or rents, often of great extent, and filled with quartz and magnesian earth, traverse indiflferently the d xviii GEOLOGY OF SCOTLAND. several members of the series, dividing them into large rhomboidal or talrakr masses, and running more or less oblique to the direction of the beds. Where the mica prevails the surface of the rock has a smooth, glossy appearance ; and where indented by the ripple-mark-a frequent and well-marked feature of the more flaggy varieties —there is superadded a lively and agreeable aspect to the generally dull exterior. An interesting and important inquiry remains : whence the source of this enormous mass of sedimentary deposit?— a question all the more difficult and compbcated by the intervening distance from the Grampians, whose primary and granitoid rocks so obviously supplied the materials of their neighbouring strata. The problem is one of still harder solution, when it is considered that nowhere, m the whole southern range, are there any imbedded fragments of granite, gneiss, or mica-schist, so as to indicate even the specific characters of the rocks whence they were derived. But still, as already shown, abundance of materials were high above the waters, and lofty pinnacles of rocks were scattered along the western shores, encircling the whole line of coast from the Grampians to the Mull of Galloway, and southwards into Wales. These doubtless, however altered and re-arranged, were of sufiS- cient mass for all the depository sediment required, and which connects them so much in quahty, struct ure^ and age, with the Silurian formations of England, Wales, and Ireland— rocks all of them of an age anterior to that when the Alps were raised above the sea, and while the greater part of Europe was occupied by the. ancient ocean. The Organic Remains, in this series of Scottish rocks, are not abundant, approaching in no degree to the numbers interspersed among the beds of the sister kingdom, where some of the limestones of the formation are nearly composed of animal exuvi«. Here, too, they are scattered at wide intervals along the line of strata. The principal locaHties in which organic bodies are found are the hme quarries of Wrae, near Brougliton ; Greiston slate quarry, near Traquair ; Girvan, in Ayr; St. Mary's Isle, Kirkcudbright; Loch Ryan and Little Ross Island clay- slates, on the western coast. These interesting relics carry the mind back, in review, to the beginning of life upon the globe, when we witness the very dawn and commencement of earthly enjoyment— the first forms and families of creatures privileged to eat at the banquet of creation. Though generally low in the scale of animated lieing, the forms of these earliest specimens of organisation are as perfect and beautiful as those subsequently ])roduced, each after its kind, demonstrating how Nature at once stamped, with her plastic hand, in these morning days of existence, the lineaments of symmetry and adaptation on everything that has life. The entire casts, and even bodies, of some species are completely preserved > their organs of motion, feeding, and protection, are all fully developed ; and in one tribe,, the trilobites, the eye, formed of four hundred spherical lenses in separate compart- ments, is still entire, and in the most perfect state of keeping ; whereby man learns that, many ages ago, the air he breathes and the light by which he sees were the. same as at this hour, and that the waters of the sea presented to their inhaMtauts the same qualities of the most lucid transparency. The organisms belong ex- clusively to marine animals, and these chiefly to the invertebrate tribes termed! graptolites, zoophites, trilobites, and molluscs, all destitute of an interior bony skeleton, and suited to live in shallow water and on muddy bottoms. Nor are the remains of fishes wanting, belonging to the order of placoids, and so deno- minated from the broad scales or plates with which they are covered. Of these there are distinct evidences of several genera and a great many species, differing GEOLOGY OF SCOTLAND. xix from any nOTT existing, tut of an equally higli type of organic being. Vegetables would also appear to have been abundant enough in the bays and estuaries of the Silurian seas, although the Scottish rocks have contributed as yet but comparatively little to the fossil flora of the period. The plants are allied to the ficoids and algse of the present time, which supply the food to several existing races ; and, as showing the persistent analogy of nature through her long series of creations, there were pentameri, terebratulse, and other forms of shell-fish, that fed upon the sea- weeds which covered the rocks of the Silurian age of the world. Others of the order cephalopoda were carnivorous, and adapted with organs to prey upon each other, as the orthoceratites and nautili, which have their congeners in our present seas, and stiU distinguished by their strong predaceoas instincts and roving habits. As the Grampians consist of the earliest series of the primary rocks, so is this southern range chiefly characterised by the fossils of the lowest palaeozoic system, and therefore ranks in age with the Cambrian or oldest Silurian group of the English rocks. The district of country which it traverses, though not so bold and mountainous, partakes in many localities of the characteristic scenery of Wales, the Cumberland Lakes, and the Northern Highlands. While there is much of sweet upland pastoral, and the loveliest dales verdant to their tops, hills of a soft rounded form or with long flat summits, there are also many noble gorges and steep acclivities, and lofty peaks, which give grandeur and diversity to the borderland ; otherwise famed for its classic rivers, their charming tributaries, and ancient warlike Peels. The associations here are all of early times, physically and historically — rocks worn to their bases, and ravines that scarcely admit a ray of light to the waters that have strained through them for ages — cascades and waterfalls among which the kelpies and wizards of other days have played their fantastic tricks — and beds of indurated strata which contain the relics of the earliest finny tribes of creation. Professor Jameson says — " The mountains of this formation have usually a gentle acclivity, and its cliffs are not so steep and rough as those of mica-slate or gneiss. It is more favourable to vegetation than any of the rocks already described ; and it is observed that the quantity of vegetation increases from granite to clay- slate, a circumstance which appears to depend, not so much on the lower level of the outgoings of its strata, as on the nature of the rock itself. We can thus observe a gradual change in the shape of mountains, also of their cliffs and valleys, fi"om granite to clay-slate; and these differences are so striking and characteristic, that a long experienced eye can, at a glance from the summit of a mountain, point out with considerable certainty the different formations of which a country is com- posed. Landscape painters, by confounding together all these differences, or by combining them irregularly, fail not only in accuracy, but in giving their work that appearance which shows, at first glance, that it is not only a copy of Nature, but a copy by one who has formed a distinct conception of the general and particular features of the inequalities observable on the surface of the earth. Some affect to maintain that the grand features of mountains and plains are different in different zones. Thus, that in the torrid zone, for example, the shape, cliffs, and other appearances in mountains, are different from those in the temperate zone. This opinion, however, is erroneous, for the same formation in all countries presents similar external characters; and, as the great formations are universal, no such differences can exist. It is true that the blue colour of the heaveij, its degree of XX GEOLOGY OF SCOTLAND. illumination, the appearance of distant mountain-vapour, the shape of animals, the luxuriance of vegetables, combined with the features of mountains, will form a par- ticular character for each climate; but still the aspect of the rocks of the same formation, in whatever country they occur, will be the same. Thus, cliffs of granite and mica-slate have the same appearance in India and Siberia as in Scotland ; and the valleys of the Urals do not differ in shape and other features from those formed by similar rocks in this neighbourhood."* It is thus that Greology, under its great physical aspects, illustrates even the pursuits of the artist and furnishes the details of perspective. As far as landscape depends on forms, it wiU be found that it is very often essentially regulated, as to its beauty or deformity as well as its character, by the nature of the rocks of which the district consists. This is often true, even where the rocks themselves are not visible ; as the character of the surface, the outlines of the hills, the forms of the shores and headlands, and other circumstances, depend on the geological nature, position, and arrangement of the rocks beneath. Nor is even the aspect of a culti- vated country, where the original configuration is so obscured or obliterated almost by plantation and husbandry, so independent of the subjacent minerals as might be imagined. On the contrary, many districts in England as well as in Scotland, have a character in their vegetating surface, or agricultural aspects, so marked as not only to indicate the nature of the rocks beneath, but to enable an experienced geologist to decide where one kind terminates and another begins. Thus compare the bare ragged escarpments of Criffell, and all the bleak granite ridges of Galloway, with the rounded tops and verdant sloping sides of the Terregles, Dalveen, and Lowther hills, and no ordinary observer can fail to discern the marked distinction between the contour of the primary and the transition series of rocks. The lofty- pointed Fells around the soarces of the Teviot and its tributaries, composed chiefly of trappean porphyries, so craggy and splintery, are as clearly again distinguishable in form and outline from the grauwake-schists of the mountains from whose deep ravines issue the waters of the Tweed and Clyde. Look into the smooth upland vales of the Ettrick, Yarrow, and Grala, and, because lying on the same formation, how close their resemblance to the charming dales of Ewes, Esk, and Liddle, with scarcely a tarn or lake in all of them to break or diversify the pastoral greenness of their surface. These distinguishing features are very notable among the older systems of rocks, whose strata are nearly vertical, or all highly inclined upon the granite ; but when we descend among the secondary formations, the old red sand- stone and coal measurers, we will find, where the rocks are seldom exposed, the physical differences and the characters of the landscape not only widely changed from all the former, but strongly contrasting with each other. The benefits of an extended agriculture, of rich, deep loamy soils, of gentle undulating plains, of diversified woodlands and verdant meadows, will accompany us henceforth in our description of the systems of rocks which characterise the Lowlands or central districts of Scotland. A Salvator Rosa drew his inspiration among the rugged defiles of the Alps ; the eye of Wilkie rested upon " mine own blue Lomonds,'' and his quiet and gentle spirit dwelt among the homes and landscapes of village life; the smooth river for the leaping torrent-™ the sheltered field for the wild waste. As not unconnected with the subject, and before leaving the older systems of rocks, it may not be out of place to introduce here the substance of a very curious , . * Manual of Mineralogy, p. 363. GEOLOGY OF SCOTLAND. tt\ and important speculation of Dr. M'Cullocli's, concerning the comparative earlinesa of the seasons in the northern districts. Like most of the Western Isles^ South and North Uist, Barra, Vatersa, Sandera^ and all the neighbouring islands are composed of gneiss ; they are all high, attaining a general elevation of 800 to 1000 feet, and in some of them there are mountains 2000 feet high. The western shores are flat, sandy, and generally arable, followed by boggy brown tracts of low hills, interpersed with lakes, which are again succeeded by high mountains. The earliness of the harvest is a remarkable circumstance in all these islands, and cer- tainly considering the nature of the subjacent rocks, very unexpected, as the climate is very moist, like that of most of the inner islands or the mainland, where it is a month or six weeks later. "This may be attributed," says Dr. M'Culloch, "to the dry and calcareous nature of the soil, in some measure ; but I believe that it depends as much on another circumstance, which will equally explain the well- known forwardness of the harvest in Moray and on the east coast of Suther- land ; a tract which, in the same manner, exceeds in earliness the districts further to the southward, and in a very great degree all those on the west coast. That to which I allude is the greater proportion of light, or sunshine, which these districts, remote and indifferently situated as they are, enjoy when compared with many other tracts in the different parts of Scotland just named. The immediate cause of this must be sought in the relative position of the mountains towards these places, and in the direction of the prevailing winds, as these act jointly in causing the detention of clouds over a particular region. The great annual supply of clouds, as of rain, is from the west ; and they are brought by the predominant western winds. The western-most land, which forms this insular tract, is too low and narrow to arrest their flight, whence they pass freely over all the outer chain except Harries ; which, by detaining them, becomes an exception to the rest of the Long Island, being a dark, rainy, and late country. But as they arrive at the inner islands and the mainland, they are stopped, partly by the Highlands of Skye and Mull, but still more by the great western mountainous tract of the Highlands, producing a dense and dark atmosphere through which the sua seldom shines, even for a few days, without long and frequent interruptions. An undue proportion of rain is a necessary consequence ; and that of course aggravates the evil, although it must not be considered the sole cause. In that rain the clouds are partly di;asipated, as they also seem to be by being re-dissolved in the air ; and thus the eastern districts enjoy continuous sunshine, often for weeks, when the western are wrapt in gloom. If this view is correct, a register of light by means of a proper apparatus, ought to enter as much or even more than that of the barometer and thermometer, into the scientific means of estimating the nature of an agricultural climate." * Geology is thus intimately connected with hygrometry, and both in many interesting relations with agriculture. The soils of the earth depend, for richness and variety, upon the qualities of the rocks beneath, and are sandy, clayey, calcareous, or loamy, according as they rest upon, or are within the influence of, the prevailing system in which these constituents exist. The dislocation and dip of the rocks afford a passage for draining. Their height and distribution collect the vapours, or give a free admission to the air and light of heaven. • The Highlands and Western Islands vol. 3, p. 21, xxii GEOLOGY OF SCOTLAND. THE DEVONIAN SYSTEM, OK OLD RED SANDSTONE. The system of rocks on which we are now to enter leads us a step onwards as well as upwards in our geological history, where we are presented with new aspects of the country, introduced to new forms of life in its waters, and with new features and arrangements in its mineral masses. The change is a remarkable one, in the shifting of its outer scenery no less than in the singular character of its various tribes of inhabitants. A new dynasty crosses the stage of animated exist- ence, and is ushered in by as great a revolution in the laws that had hitherto pre- vailed in the mineral kingdom, as the convulsed condition of the globe has shown repeatedly to have occurred. The colour and constituents of the rocks are all wonderfully altered. The transition from the beautiful crystalline masses of the older formations into the fine grained and schistose strata of the Silurian series is gradual, and in its first stages scarcely perceptible. A type and mould of far coarser materials, and a distribution of thicker and generally less homogeneous beds, characterise the Devonian order of things ; while the seas were tenanted with families of creatures dissimilar from those of the anterior era, and whose enamelled skins were of such enduring texture as to rival, in brightness and strength, the scaly appendages of every existing order of fishes. This may be justly termed the Fish Epoch, and constitutes one of the most remarkable portions of the natural history of our own country ; so numerous are the fossil remains, so singular their forms, so diversified and yet so normally alike, so splendid their attire, so perfect their pre- servation, and aU so distinct from everything that now swim the waters or occupy their deep coral caves, that we seem to be transported back in imagination to scenes of romance rather than reality — the relies of a physical drama whose agents and pageantry have become utterly extinct. The rocky matrix in which their remains are entombed is as evidently the wreck of a former world, water- worn fragments of granite, quartz, schist, and other rocks ; — a reconstruction, amidst vast and sudden changes of the inorganic crystalline formations, for the still more beauti- ful elaborations and increasing progress of organic existence. The old red sandstone formation, so interesting in every respect, consists of three principal series or groups of strata — lower, middle, and upper — which are all strongly characterised by a granular structure, and more or less by a reddish colour. Overlying unconformably the Silurian strata, or resting on them nearly at right angles, the beds of the old red indicate, from their position and relations, a vast shift in the sea-bottom on which their materials were collected — the steep abrupt shores consisting of the primitive formations, or lifted into bolder and loftier ridges landward. The immense thickness of the sandstone as clearly demonstrates the deep hollows or troughs into which they were cast. Hence the great mass of the conglomerate, or the lower series, consists of fragments principally derived from the older rocks in the vicinity; and so persistent is this feature of the formation, that the deposit, all over Scotland, bears a resemblance to the nature of the rocks with which it is locally connected. Thus, on the line of the Lammermuirs, grauwake, clay-slate, felspar, porphyry, and hornstone, along with a sprinkling of quartz and a few primary boulders, are the prevailing ingre- dients ; whereas, on the line of the Grampians and the great primary mountains to the north, granite, gneiss, mica-sehist, quartz, and hornblende, of every variety of size, in fragments and boulders, almost entirely exclude the transition class of rocks. GEOLOGY OF SCOTLAND. xxiii It is matter, too, of indifference, whether the geologist continues his researches into this new group of strata over the border district, whither our description in the former chapter has led us, or he returns to resume tliem over the northern frontier, where the old red sandstone is developed on a scale almost co-extensive in area with the primary series. The few pinnacles then above the waters still stand out in bold relief': Criffel, Queensberry, Moor-foot, Hart Fell, and others, commanding from their lofty summits all the shallows, creeks, and bays, into which their debris was carried; and the yet higher Bens of the Grampians, overlooking the great valleys, straths, and indented coast which mark the deeper basins into which their spoils were collected. Flanking the primary and transition series of the Westmoreland, Cumberland, and Welsh mountains, these sandstones are largely developed in Devonshire, and are hence denominated the Devonian System of English Geologists —their position throughout distinctly showing the various sources and the littoral character of the deposit. The colouring matter of this formation consists Gf the peroxide of iron ; and, though still a matter of hypothesis among geologists, the opinion which ascribes it to volcanic origin is the one generally adopted, as it is indeed the only one which seems adequate to account for the phenomenon. The period was one undoubtedly of great disturbance, when the crust of the earth was widely fused and broken up by igneous action; the seas would consequently be affected to as great an extent with metallic impregnations ; the materials conveyed in a loose unaggre- gated state, would be easily suffused with the penetrating element ; and, as a curious corroboration of its deleterious influence on animal substance, the organic remains are fewest in number, as well as in the worst state of preservation, in those groups and strata of the formation which are the most deeply tinged with the dis- colouring solution. The grey flagstones of Strathmore, and the yellow sandstone series of Cromarty and Dura Den, are accordingly rich in specimens of their respective flora and fauna of the period; but comparatively few of either are traceable in the more deeply reddened strata and coarser conglomerates of Eoss and Sutherland. The external characters of the formation, in its various localities, are thus too Well-marked to need any minute description of its mineral constituents. Taken in the mass, it has been estimated at ten to fifteen thousand feet in thickness, presenting a succession of sandstones, alternating with subordinate layers of sandy shale, thin dark-coloured tilestone, and beds of impure concretionary limestone. The calcareous rock is termed cornstone ; it is almost destitute of organic remains, and is of little use as a limestone. While fine-grained strata, as well as conglomerates, are found in all parts of the series, in the lower, middle, and upper divisions, it may be con- sidered, as already stated, the general law in their order of superposition, that the coarser beds all lie nearest the great mountain ranges, and that the finer and softer ones take their positions successively more sea-ward. The Sutherland, Caithness, and northern portions of the formation, which are densely clustered round the primary series, are for this reason not only the coarsest in mass, but the oldest in age and of the greatest extent in vertical thickness. Coul Beg, Coul More, and Suil Veinn, on the north-western coast of Ross-shire, and resting unconformably on a bed of gneiss, form three immense insulated hills of about three thousand feet high. The hills of sandstone here are of every variety of aspect — round, conical, ridged, or serrated. They are sometimes isolated, sometimes in a prolonged range, with naked and pre- cipitous rocky faces of a thousand feet in depth, and with an aspect often as rugged xxiv GEOLOGY OF SCOTLAND. as tliat of the mountains of Skye. The sandstone in some localities constitutes the entire mass of the mountain; in other places it is observed to rest on granite or gneiss at a considerable altitude^ and in not a few of the mountains of Ross and Sutherland it is found only on their summits. The stratification is in general dis- tinct. Where the angle of inclination is low the strata are thin and equal, possessing a schistose flaggy structure, and exhibiting on the summits of the mountain, as the two Ben Derigs in Durness, an even surface resembling a pave- ment of loosened tHes ; but where the angle of inclination becomes considerable, the distinctness of the stratification diminishes, and wherever it assumes the vertical position the divisions of the beds are scarcely recognisable, the rock acquiring the aspect of some granites or gneiss, into which it seemingly graduates, being split into prismatic or angular fragments. Looking from an elevated summit over these northern sandstone districts, composed of so many insulated mountains which are caped in one place, encircled round their base at another, and here and there accom- panied with broken fragments of the formation, it is impossible to resist the con- clusion that the whole countiry has once been covered with a united stretch of sand- stone, all now abraided and washed away, the harder portions remaining like pillars of gigantic masonary, and the deep gorges of the rivers showing the still older and more enduring foundations on which they rest. The extreme depth of this deposit, as far as it can now be discovered, may be measured by the ICea Clock in Ross- shire, a mountain of nearly three thousand seven hundred feet, or as high as Ben Cruachan of the primary system,— where the strata are nearly horizontal, and extend from the summit to the base, which dips into the sea. The detached por- tions which occupy the shore indicate the subaqueous range and connection ; and ia viewing its relations to the islands of similar formation. Dr. M'Culloch justly infers that the large intervals now occupied by the sea were once parts of a contiauous tract of land. Southward of the Grampians, the beds thin out, and become more slaty and fissile in their texture. This is the general character of the sandstones in Strath- more and the basin of the Tay, in Strathearn, and Menteith j while in Roxburgh and Dumfries shires they are generally more flaggy and composite in their mineral qualities. Mottled bands of a purple and fawn-coloured shale, and though close- grained yet extremely friable, are not unfrequently interspersed ; as near Auchter- gaven, the environs of Creiff; and the high ridges that slope westerly to Callendar. Towards the upper beds of the middle series there occurs a well-marked stratum of hard texture, and an excellent building- stone, which is dotted all over with whitish spots of a spherical form. These spots generally inclose a dark centrical nucleus of the size of a garden pea, and owing to which, whether of animal or metallic origin, the discharge of the oxide has been occasioned. While the highest portions of the upper series merge into, and are scarcely distinguishable from, the sandstones of the coal formation, either in mineral texture or colour ; those, again, of the lower series, just as insensibly graduate in many places into the crystalline primary rocks on which they repose, the altered sandstone being fused into quartz -rock by plutonic action. This form of the sandstone occurs in various places near the southern ridges of the Granipians, in Glenshee, at Cally Bridge, and near Dunkeld, where it is in contact with the mica-slate and limestone, and has been generalljr described as belonging to these formations.* • Qeo. Jour, Nq, 30, p. 126. GEOLOGY OP SCOTLAND. sxv The geograptical range of the formation is of great extent^ being largely deve- loped in every quarter of the globe. It forms vast areas in Russia and Central Europe^ in Siberia and Tartary, along the flanks of the Himalayas and upper plains of India ; it likewise extends over large portions of Australia^ the boundless deserts of Africa, whence their arid sands are mainly derived; and in North and South America it is no less abundantly distributed. In Scotland, this rock deposit ranks next in extent to the gneiss — the largest of the primary series — and covers nearly 5000 square mUes of surface, of which about a half lies to the north of the Gram- pians. The organic remains are nearly the same in every region, the same species inhabiting the ocean at one and the same time, ia India as in Russia, in Scot- land as in Africa and South America. As far as the researches of geologists have yet extended, the collections of fossils from the Scottish deposits are more numerous, as well as diversified in genera and species, than those of any other country, perhaps than all the rest of the collections put together. This shows how much has still to be done in this department of geology — what spoils may yet be gathered from the buried dead of past ages — what trophies have still to be won to the science over these immense fields of research. The topographical features of the old red sandstone district are in general varied and irregular ; if in hUls, rising in easy undulations, or swelling into round conical tops ; in the plains, where the strata lie flat, the scenery is generally of great richness and amenity, the fields fertile and covered with the finest loams ; where, debouching from the mountains or girdling the sea-coast, the glens, valleys, and lochs are diversified with every species of simple beauty and wild grandeur — the leaping cascade, the rushing torrent, the gentle river, having each their appro- priate places in the heights and hollows of this friable formation. The pictm-esque character of the valleys of the Jed, Rule Water, Teviot, and Tweed, is derived from its precipitous cliff's worn by the rivers in the course of ages. The Crig-up Linn, the deep pools of the Nith, the Falls of the Clyde, the romantic shores of Largs, the Cumbraes, and Rothsay, are all cut and moulded on the same variegated flesh- coloured sandstone. The Ochils and Sidlaws may be regarded as the type of its hiUy or general physical features, along with their numerous valleys and ravines ; of which the more remarkable are Glen-eagles, Glen-farg, and Dura Den in the former, and in the latter the Dens of Balruddery, Rossie, and Baliggarny, which either cut through or open upon the strata of the middle and upper series. It were endless to enumerate the many remarkable places and admired scenes formed in this rock, where it flanks the southern ridges of the Grampians, lines the trough of the Great Canal, or fringes the coast from the Spey to Dunnet Head, and from Cape Wrath to Loch Carron ; sometimes rising into mountains two and three thousand feet high, or broken into shelving precipices and flssures of extra- ordinary grandeur, or hollowed into bays and caves by the unceasing action of the billows. The Orkney Islands, sixty-seven in number, are chiefly composed of the old red sandstone, and, agreeing so closely in external aspect and mineral structure with the general features of Caithness, there is little doubt of their having formed at no very remote period a continuation of the mainland. Nor may it be unin- teresting to remark, as a curious illustration of the wide diffusion of the forma- tion in every district of Scotland, that the ancient monasteries, with scarcely an exception, are chiefly constructed of this rock, from the circumstance perhaps of their lying in the immediate vicinity, or of being built directly over the con- venient and easily excavated materials. xxn GEOLOGY OF SCOTLAND. The Organic Remains of the old red sandstone would require, of themselves, several chapters of description. It has been termed the " Fish Period," so abun- dant and curious are the fossil specimens preserved of it. Nothing, however, beyond a simple outline of their general features, and the more remarkable localities in which they are found, can be given according to the necessary limits of our sketch. There are four great divisions or natural orders of fossil fishes, as admitted by geologists, distributed in the several systems of rocks which compose the earth's crust. , The latest classification is that of M. Agassiz, in the Poissons Fossiles, the standard authority in fossil ichthyology ; and where, proceeding upon the characters of the scales and plates, the following orders are described: 1. The Placoid, or broad-plated scale. 2. The Ganoid, or shining scale. 3. Ctenoid, or comb-shaped scale. 4. The Cycloid, or marginated scale. Now these different orders are not promiscuously huddled together in the rocks of the earth, but have each their distinct positions in the vertical arrangement of the fossiliferous strata, and serve to characterise the formations with which they are connected. Generally speaking, the two former orders belong to the older secondary formations, and the two latter to the newer secondary and tertiary series. And so, according to the geological chronorneter, were the successive periods of their introduction upon the stage of organic life. But, besides the form of the scales, the two divisions of these natural orders are no less remarkably distinguished by the qualities and form of the inner skeleton. The fishes, for example, of the present age are arranged into two great classes, the cartilaginous arid osseous. To the former belong our existing rays, sharks, and sturgeons; the latter include the cod, herring, and salmon families. In the cartilaginous class, the internal framework is soft, destitute of fibre, and contains scarcely a trace of calcareous matter ; while the Osseous tribes. On the other hand, are constructed internally of true bone, like that of birds and quadrupeds, and which consists of a fibrous texture and of great hardness. But, as if to make up for any deficiencies in strength and firmness arising from the carti- lage, nature gave to all the creatures of this class, in geologic times, a strong external armiture ;of hard osseous scales, coated with enamel, and capable of the greatest endurance. The head sometimes consists of pure naked bone. The skeleton in all of ; them extends to the extremity of the tail, and hence termed Heterocercal or uiiequally-lobed, which serves to distinguish them from the two last orders as well as existing races with an osseous skeleton, whose tail-fins are Homo- cereal or equally-lobed ; and thus covered cap-a-pie, over the length and breadth of the body, the plaeoids and ganoids of the ancient seas were admirably suited to the convulsed condition of the element in which they were placed. The ganoid order is the prevailing type of the old red sandstone. They are nearly all of a family, termed sauroids, as possessing in many respects a reptilian or lizard caste of organi- sation ; the scales are thick and bony, often two or three inches broad, and com- bined with their curiously interlocked arrangement, artistically mailed upon each other, these creations^f so early a period are recovered often in a state of perfect entireness, in colour, enamel, and freshness even finer than those of any succeeding age. This discovery of the Swiss naturalist, whereby he finds all the important distinctions of structure to harmonise with the scales and dormal covering, is of the greatest importance in geology. Without it, indeed, no other trustworthy method of classification could have been found. The system of Cuvier, as applied to existing fishes, and which chiefly proceeds upon their internal characters, combined FOSSILS CHARACTERISTIC OF TH E OLD RED SAMDSTONE- 1 , Txiloiite . 2, Coccbste-oE., 4;, Osteolepis, 5. fioloptycliius Andersarii, 6 „ Pa.TQ.piir actus AnAersoni . .7, Scales. GiEOLOGY OF SCOTLAND. ^^^ •witli the form and disposition of the finsj could have been of little or no use where the skeletons of fossil species are seldom detected in any considerable portions, and where the teeth, spines, and other fragments, though obtained in abundance, afford too imperfect data for arrangement. The skin, on the other hand, with all its scales and plates so remarkably preserved, is the organ which indicates not only important anatomical and functional distinctions, but also shows the relation of every creature of earth, air, or water, to the element in which it moves. Accordingly, as Cuvier, by means of a single bone, and often by the fragment of a bone, was enabled to detect the order and genus to which it belonged, and thereby to produce his wonderful restoration of the huge monsters of Montmartre and the tertiary epoch, where every part fitted so precisely to its place, so has Agassiz, by the aid of a solitary plate or scale, carried us back among the earliest creations of the deep, demonstrated the several orders to which they belonged, and pointed out the habits and conditions under which they flourished. Some were suited to muddy bottoms, some rejoiced in clear blue waters, some were herbaceous, and others carnivorous, armed with teeth and claws capable of breaking the hardest substances. The palseocarcinus, or lobster of Balruddery, was several feet in length ; the cephalaspis, or seraphim of Glammis and Carmylie, consisted of a head of naked bone, nearly three times the size of the body ; and the phyllolepis, or leaf-scaled fish of Clashbennie, was covered with enamelled plates of the enormous dimensions of half a foot in diameter. Such researches, and especially discoveries so minute, correct, and interesting, exalt the science with which they are connected, and show principles of investigation worthy of our closest study, which can still, at this remote distance of time, detect the surprising methods and analogies of Nature in these beautiful and endming tissues of her earliest works. The ways of the Almighty in all ages are one and the same : the greatest diversity combined with the greatest harmony — everything adapted to its place in the scale of being, and all illustrative, in the most eminent degree, of divine wisdom and foresight. The districts in which these interesting organic remains have been most abundantly found are the counties of Caithness, Sunderland, Eoss, Inverness, Nairn, and Elgin, and, perhaps, most richly of all, in the Orkneys near Strom- ness. The central district of Strathmore, included betwixt the Grampians and Sidlaws, is next the most distinguished for the varieties and numbers of its fossil treasures. The Carse of Gowrie, Dura Den, and Stratheden in Fifeshire, are no less remarkable for the abundance of specimens imbedded in their strata. The border counties, and other localities of the formation, have as yet yielded them in small quantities, sufficient enough for identifying the deposit but not to claim for them any separate description. Ichthyolites, or fragments of the bones of fossil fishes, are abundant in the sandstones of Caithness and Cromarty, and other localities in Scotland, but shells are rare; while in Devonshire, and other parts in England, testacese and crustaceans are abundant. The geogra- phical distribution of the old red sandstone, now referred to, may be considered as nearly as possible corresponding with tl\e geological divisions into the lower, middle, and upper series ; and, therefore, as the most characteristic of the fossils belonging to each series, it may suffice to notice those which are the prevailing types of their several districts. 1. The northern district, which contains so large a development of the lower series of the formation, is remarkable for four genera of fossil fishes, of the ganoid order, namely, the asterolepis, osteolepis, coccosteous, and pterichthys. The firsi xsvili GEOLOGY OF SCOTLAOT). is found in the Orkneys, in a state of almost perfect preservation, and is the largest of all the genera belonging to the period. It is variously estimated, according to its ablest historian, Mr. Hugh Miller,* from eight, ten, to even twenty-three feet in length, resembling, in all its equipments of bulk and strength, the sword-fishes, sturgeons, and sharks of our present seas. The scales are round, large, and divided into grooves, radiating from the centre of the organ. Hence the term asterolepis, or the star-scale fish. The cranial buckler was large and flat, in some specimens about eight inches in length by six in breadth, traversed by three slightly elevated ridges, and in size might have furnished a substitute for the frontal bone of an elephant, or the largest of existing crocodiles. The under jaws were furnished with two rows of teeth, the one row small and densely set, the other thinly set, but very large, bent and tvristed, and, after the reptilian type, were laterally fenced with two sharp-cutting edges- The opercules and hyoid hones were likewise of great size and massiveness, the former thickly studded with r-like tubercles, and the divisions of the arch of the latter resembled those of a small Gothic vdndow, in which the central muUion parts into two branches at top. As with these, so with all the other portions of the ossi- fication of this earliest vertebrate type of the lower old red, every bone, plate, and membrane being exactly suited for their place, and of the finest and most admirably formed structure. Belonging to the highest division of the animal kingdom, the asterolepis — all of whose organs of sight, smell, hearing, and taste, are so delicately preserved in the matrix of the rock — demonstrates a high style of organisation; showing that nature, in these morning days of existence, did not first fashion the minute and imperfect, whence were gradually eliminated the larger and more com- plicated structures of progressive animal life, but created at once models of the highest kind and of the fullest dimensions. No theory of development, from the little to the great, from the simple to the more perfect, from a condition of semi- animate to the higher states of functionary action, can be maintained on the paleontology of the old red sandstone. This single witness from the deep over- throws the whole baseless fabric on which the Vestiges of the Natural History of Creation" rests its preposterous assumptions, and shows the theory to be as devoid of any foundation in science as it is repudiated by the feelings of our moral nature. There is no progression. There is no transmutation from family into family, in aU that exists in the underlying Silurian rocks, so as to give anterior geologic lineage, on a lower scale, to this earliest example of the succeeding Devonian System. The asterolepis moves as independently, and individually, in its orbit of animal life as the stars in their courses; the nebular and development hypothesis are equally unsupported by fact, and by the revealed law of creation. The remains of this remarkable fish are found in the greatest abundance in the sandstones of Orkney, near Stromness ; in some of the beds they are so numerous as to obliterate all traces of the rock itself; and their mode of preservation is no less singular, presenting an instance of Nature's embalming which surpasses all the most skilful manipulations of the chemist, and as simple as it is perfectly conservative of every plate, scale, tooth, and bone, in their original integrity. The substance of the creature itself seems to be the only element employed in the preparation. The animal matter has been converted into a dark-coloured pitchy mass, resembhng bitumen, or coal-tar, and which, thickly enclosing the body, has subserved equally * Foot- Prints of the Creator GEOLOGY OF SCOTLAND. xxix the purposes of stroud and coiRn. It possesses the consistency as well as tenacity of "wax, and has been used as a substitute. And thus steeped in tbe residue of its own blood, muscle, and flesh, the skeleton of the asterolepis, of the size of a por- poise, and whose age in the geologic scale the years of human reckoning cannot number, is again restored in all its enamelled polish and beauty, not a bone dis- placed nor an organ disfigured. The pterichthys and coccosteous are more abundant than the former; so characteristic, indeed, of the series, as to be obtained in every locality of its northern range — at Cromarty, Gamrie, Lethen-bar, Seatcraig, Altyre, Tynet-burn, and the Dipple on the Spey. Some of the finest specimens are found in nodules and a con- cretionary limestone, which have served as a better matrix than the oxidized sand- stone; every part of the body, internal and external, the stomach and its contents undigested, even the pebbles and grains of sand intermixed with the food, are all there, to attest the form and the instincts of creatures of which there are no existing analogues. They are considered to be true fishes, though more resembling crusta- ceans from their thick bony envelopes. They are covered with nearly the same number of plates, differently disposed on the head and carapace. The tail in both is long, and belongs to the homocercal or equi-lobate structure ; thus indicative of an osseous skeleton, and the cause, perhaps, of the perfect preservation of so much inner integument. The coccosteous derives its name from the beny-like tubercules which dot its plates, being the Greek compound {kokkos, a berry, and osteon, a bone) for the descriptive term. It differs from the pterichthys, besides in the number and disposition of the plates, in having a less elongated head, and the absence of arms or winged appendages, which are so characteristic of the pterichthys as to serve for its generic appellation. Hence the name — pteron, a wing, and ichthys, a fish. But whether so curiously placed on the body for defence, or as aids to locomotion, or, like the fljing fish of modern times, to assist its elevation, for breathing p^irposes, into the air, these organs of the pterichthys have not been pronounced upon by palaeontologists. There are several species of both genera; and so abundant are their remains, that the seas of the period must have been literally swarming with them, pursuing their prey among the rocks and shallows of the waters which, in the Silurian period, were occupied by the trilobites, the crustacean types of the age, as the pterichthys and coccosteous were decidedly of theirs. The osteolepis, more fish-like in its form and general structure, is also very prevalent in the old red sandstone rocks. It was one of the earliest discovered fossils in the Caithness beds, and received its name, under the classification of Cuvier, in consequence of the osseous character of its scales [osteon, a bone, and lepis, a scale) ; but as all the coverings of the fishes of the period were of the sub- stance of bone, the designation fails in some of its most remarkable peculiarifes. Nature, perhaps, has never formed any similar creature with an outer vesture so brilliant in its colouring, compact in its arrangement, and enduring in its texture, as that in which she arrayed this early specimen of her marine workmanship. Combining the lightness and agility of the feathered tribes, there was the hard, impenetrable coat-of-mail over every organ, membrane, and spot of the body, which so remarkably distinguishes the sluggish tortoise and chelonians. of the present time. The covering of the fishes already noticed consisted of detached plates, which met at the edges of each other, and were united like the sutures in the bones of the human skull, forming a uniform envelope round the entire body of the animal, and thus better adapted for strength than for symmetry or fleetness. But XX.X GEOLOGY OF SCOTLAND. in the osteolepis the scales are arranged alongside each other, like the bricks in a ■wall, disposed in regular rows, and joined in a manner calculated at once to afford protection to the internal parts, and to suit the flexures of the body while in motion. The divisions of the head are all composed of pure naked bone, and brightly- enamelled. The teeth formed part of the jaws, not set in sockets, nor rising out of the fleshy cartilage. The fins and tail consisted of the same substance, hard, shining, enamelled bone ; the rays of these organs were as numerous and thickly set as the feathers in the wing of a bird. The scales were all of bone, coated with enamel, and glistened like plates of gold. Thus eveiy portion of the osteolepis was enveloped in a network of bone, elaborated iato every shape and form of organic structure, and after subserving the purposes of animal life ages ago, the whole remain undisplaced and entire, as an evidence of the beautiful diversities and wonders of Creation. 2. The middle group of the old red sandstone covers nearly the entire district lying between the Grampians and the Ochils, and consists of conglomerate, micaceous slaty bands, cornstone, tilestone, arenaceous marls, and thick beds of grey and flesh-red sandstone. The cephalaspis and holoptychius are the vertebrate remains that chiefly characterise the group. The relics of the cephalaspis are exceedingly abundant, and are very widely dispersed in the series, but are found most numerous, as well as in the best state of preservation, in the marls and tile- stone. The cephalaspis, or buckler-headed fish, derives its name from the great size of this organ, being about three times the size of the body, and from its being covered with a buckler or shield. The shield consists of one large plate, of a lamellar structure and crescent-like form, which terminates in two long projectionSj or pointed horns. The other plates of the head are united into one osseous case; and the whole consisting of hard bone, protected by equally hard enamelled scales, this fish, though never found above a foot in length, must have proved no easy capture to its predaceous cotemporaries. The scales of the body formed elevated bands, and the rays of the fins were covered by the membrane which everywhere surrounds them, while the entire skeleton was wrapped in bony plates, so airanged as to join or overlap each other. The fossil specimens, accordingly, are very entire, and are lifted out of the rock, as if their interment had been but yesterday. The quarries of Carmylie, Glammis, and Balruddery are the most noted places for the relics of this remarkable genus, hundreds being disinterred within an area of a few square yards ; and resembling, as they strongly do, from their cephalic shield, the trilobites of the Silurian seas, they appear to have been equally abundant with that most prolific race, and to have constituted, like them, the most singular race of their time. The holoptychius, or the wrinkled-scale fish, belongs to a family allied on the one hand to the true finny tribes, and on the other hand, particularly iu its denti- tion, to the order of reptiles. The scales are nearly circular, rough, and corrugated in ridges, with waving furrows intermediate, and are sometimes two inches in length, by an inch and a half in breadth. The plates covering the head have a dotted, shagreen surface. The teeth are double set, the one set long and slender, the other consisting of the sauroid or reptilian conical form, of great density. The head is comparatively small, forming in this respect a remarkable contrast to that of the cephalaspis ; from the position of the mouth it required to turn on its back while striking its prey ; the fins are large and distantly placed ; and thus encased all over in scale- enamelled plates, articulated and mortised after the strongest GEOLOGY OF SCOTLAND. xsxi and most flexible fasMon, tlie toloptyeMus and cephalaspis were not unequally matched for either attack or defence. The largest specimen yet found of the genus measures thirty inches in length hy twelve in breadth. It is also the first that was found. "We well remember the date — a bright autumnal day in 1839 — having visited the quarry of Clasbennie, in search of relics, only the day before its discovery J but returned richly loaded with remains of other genera — namely, scales of the glyptosteus, phyllolepis, and glyptolepis ; all abundant in the same beds, and all described and named in the monograph of M. Agassiz. Of the crustacean family the fossil relics as yet detected in the old red sand- stone are very rare. Any that have been found were restricted to the English rocks, until a huge specimen was cast up in the Den of Balruddery. Several specimens of the Calymene Sternberffii and a Brontes signatus, both allied to the trilobites of the Silurian period, were the only forms of the order belonging to the Devonian deposits. Fragments of " petrified seraphim " had been long familiar to the quarrymen in For- farshire — a name applied by them to portions of the shell or case of a crustacean, from their fancied resemblance to the conventional figures of cherubim as seen on tomb- stoaes. Some fragments had likewise been found in the Ludlow rocks, and figured by ?lurchison, in the Silurian System, as the pterygotus problematicus — the pro- visional name assigned by Agassiz. It is described in Mantell's Wonders of Geology* as a eurypterus; and at the British Association, which met at Edinburgh in 1834, the fragments of the creature there presented went under the more euphonious cognomen of the edotea. The specimen found at Balruddery, embracing almost every organism of the body, and presenting at once to the common observer a most striking resemblance to the lobster, enabled the Swiss naturalist to determine its order, genus, and species, as the palceocarcinus alatus, or the old-winged lobster. The carapace, claws, and flaps, are all in the most perfect state of preservation, ornamented externally with circular and elliptical markings, which give them aii imbricated or scaly appearance. The projections of the claws are finely developed, terminating, the larger in sharp points or hooks, and the smaller in enamelled plates like the nails of the human hand. This magnificent specimen now enriches the cabinet of Lord Kinnaird, at Rossie Priory, and occupies in its different portions ten or twelve drawers. When the portions are combined, this inhabitant of the rocks and seas of ancient Gowrie appears to have measured from five to six feet in length- and, from the great size of the shell or covering, the body might at least havv been two or three feet in circumference. Along with innumerable fragments of the lobster, the Den of Balruddery abounds in fossil remains of various kinds : annelides, shells, wiags of pterichthys, heads uncountable of cephalaspis, and, as described by Agassiz, portions of the parexus recurvus and clematius reticulatus. The same bed of rock extends into the Den of Rossie, where the search has resulted only as yet in the discovery of vast numbers of curious concretionary nodules, resembling shells, and of which an elaborate account has been given by M. Parrot in describing similar bodies [les pierres d'Imatra), and which he affirms to be des mollusques petrifices, sans coquilles. The nodules occur in great numbers In Elland Water, near Melrose, and are regarded in that land of romance as " fairy stones ;" they are of a spherical form, more or less flattened, generally consist of laminse, are from half an inch to an inch in diameter, and, whether they are organic, or simply concretions, as Sir David Brewster thinks, formed by the dropping of • Vol. iL p. 760. xxxii GEOLOGY OF SCOTLAND. water holding in solution earthy particles which cohere on evaporation ; the nodules impart a singularly striking appearance to the surface of the rock, and call back the imagination to a time when the sandstone constituted the silt of a sea-margin, whose waters, filled with so many curious forms of organic life, have long since retreated. About a mile to the westward, in the charmingly wooded dell of Baliggarny, occurs the overlying bed of the mottled sandstone, so full of spots and blotches, which stretches over great part of the Carse of Gowrie, the southern bank of the Tay, and several places in Stratheden, dipping under the Lomonds at Glen- vale. The spots are generally spherical, the transverse section forming a circle varying from a quarter of an inch to nearly a foot in diameter, and in the centre of the spheres there is generally a small pea of metallic oxide, to which the iron diffused through the stone seems to have been transferred. In accounting for the origin of these spots. Dr. Fleming has suggested that they are owing to the presence " prob- ably of some vegetable or animal organism, the decomposition of which exercised ? limited influence on the colouring matter of the surrounding rock." In corrobora- tion of this view, two specimens have been found with the scale of a holoptychius in the middle of the white spot, one of which is in the possession of the writer, and the other in that of David Milne, Esq.; in whose Geological Account of Roxburghshire the author advocates the theory of a chemical process, holding that the formation of these blotches belongs to " the same class of phenomena as the blanching process which takes place along the sides of fissures or cracks in the . old red sandstone rock/' and where there is generally a larger development of metallic incrustations, having very beautiful dendritic forms. The chemical analysis of the spot, as com- pared with the red rock, yields something in support of both theories, and is not determinate as to either. Thus, in the spot, the iron is changed fi-om a peroxide to a protoxide,* which in the red stone exists as a peroxide ; and again, in the spot, there is a trace of phosphoric acid, whilst there is none in the general body of the rock, and may have been derived from the phosphate in the scale or other organisms. Assuming the organic theory as affording the readiest means of pro- ducing the discolouration, from the infinite numbers of both vegetable and animal bodies floating in the Devonian seas, the organic matter containing phosphoric or carbonic acid, it is supposed, became gradually decomposed, and the acid, set free, combined with a portion of the iron to form a protoxide, and thus discharged the red colour. The metallic nucleus, which is of a dark bluish colour, and finely contrasts with the red and white of the rock, it may be also observed, generally bears a proportion to the size of the spheres j thus showing a correspondence between the two, whether as cause or effect, whether the influence was discharged outwardly from the centre or attracted inwardly from the circumference, and in either mode confirmative of the organic hypothesis. The sandstone extends a considerable way up the Den of Baliggarny, when it abuts against the amygdaloidal trap which has thrown the strata into the perpendicular ; at the point of junction, the sandstone is • Metals, in combining: with oxygen, combine with, different proportions of it, and these combi- nations, in conformity to the usual law of chemical attraction, give rise to compounds having very different properties. Thus in minerals, through which any metallic substance is diffused, there are degrees and shades of colour corresponding with the proportions in which the oxygen is united to the metal. The protoxide denotes the oxide formed by the first degree of oxidation, and the peroxide denotes that of the highest degree of oxidation : the black coloured oxide of ii-on, as the central spot, contains 21 of oxygen and the red coloured stone about 33, in 100 parts. GEOLOGY OF SCOTLAND. xxxiii converted into a pure quartz or flinty schist, while the trap becomes insinuated between the bedSj and welded to them by the strong fusion of heat. The interest of tl). varieties^ in all their larger outbursts as hills and ridges, are generally liiuitecl to the area of the coal-field. In the form of dykes they are of all ages, -while Jn their columnar and prismatic state they are developed, on their grandest scale, among the tertiary deposits of the western isles. The proofs of this order of suc- cession are irresistible. The upheaval of the older strata, dislocated, and resting at all angles on the edges of the porphyries of the primary and secondary mountain chains, clearly demonstrates that the plutonic agency was in vigorous operation over the whole area of the stratified rocks thus affected. The porphyritic traps, capped by these deposits, rose above the surface of the ocean, studding with innu- merable islets and forming shallows over the northern portions of Scotland. The coal measures, afterwards filling up the basins and estuaries thereby produced, were dislocated and upheaved in like manner by a new eruption of fused matter^ — the greenstone, basalt, and breccia — whose relative ages are determined by the circum- stance that these forms of trap are localised within the area of the coal metals, which have been variously affected by their intrusion. Finally, as will be afterwards shown, the alternation of the basalt with the leaf beds of the Isle of Mull, and the identity of the columnar structure of the adjacent islands — all lying within the area of the oolitic and tertiary systems — as clearly warrant the inference as to the com- paratively late eruption of these singularly magnificent piles of igneous rock. The analogy and history of the trappean family might be extended through England into France, where in both countries it can be shown that they are of the same relative ages — from the primary to the secondary formations, from the new red sandstone to the chalk, and from the period of the chalk to the most recent tertiary deposits. The Silurian rocks of Wales are identical with those in Normandy, and through both the porphyries have burst their way. The oolite, wealden, and chalk of the south of England find their types on the banks of the Seine and the Loire; and the trachyte of the one country is not distinguishable in mineral qualities, nor difl^erent in subterranean eff'ects, from that in the other. The extinct volcanos of Auvergne, in central France, bring down the narrative of these events to the verge of historic times, when the Cantal, Puy de Dome, and other volcanic peaks, rose above lakes inhabited by mammoths, dinotheriums, and other gigantic pachyderms, which have now no generic types on the face of the globe. The living fires of Etna and Vesuvius issue from the same interior storehouse, act upon, and throw up the same kinds of materials that reared the Alps, the liimmalayas, and the Andes. Thus the laws of nature may be demonstrated, in these eruptive agencies, to be one and the same in all times past and present; giving shape and contour to a planet whose stability, diversity, and conveniences are as fixed and determinate as its convul- sions and changes have been uniform, progressive, and beneficial ; and evincing a controlling Power guiding the movements of the most violent forces, to form a scene of beauty, and harmony, and fertility. THE CARBONIFEROUS SYSTEM— THE COAL MEASURES. The fertility of the earth referred to above was never greater than during the period of geological history on which we' are now entering — the period of gigantic vegetables. It succeeded to an age when the internal fires were more Ihan ordi- narily active. The crust was everywhere pierced, upheaved and vast masses of GEOLOGY OF SCOTLAND. sliii volcanic matter were rolled over the surface, or piled into lofty mountain ranges. Dr. M'Gullocli has remarkedj that, over the length and breadth of Scotland^ every square yard has been more or less affected by the trap-rocks, and the convulsive movements which their, intrusion occasioned. The class to which the older porpliy- ries belong constitutes one of the most widely-diffused systems over the area of the globe. The effects are indicative of like causes. And thus the inference necessarily follows, that the general temperature at the earth's surface Avould not only be corre- spondingly high, but nearly uniform in geographical extent with the action of the internal fires, which melted the rocks, and raised them into mountains. The carboniferous era borders on this period of fiery activity. The system of rocks composing the coal measures immediately succeeded — namely, a series of limestones, sandstones, ironstones, shales, and coal — two-thirds of wliich consist of vegetable and animal matter. The seas and the dry land were alike prolific. Masses of limestone, from 20 to 120 feet in thickness, and beds of pure coal, from 1 to 20 feet thick, are entirely composed of tlieir respective marine and terrestrial products; and when it is considered that a single coal-field will frequently contain from thirty to a hundred seams of coal, and likewise several bands of limestone, both of correspond- ing but variable thickness, it will be admitted tliat the quantity of vegetable and animal matter of which they consist indicates a period of the most prolific abundance in botli elements. Whence the heat whicli excited such wonderfully productive powers, during a particular epoch of time, but unlimited in extent over the earth's surface? The sun alone could not be the source, for liowever high the temperature thence derived, the solar heat could not have been universally, and at the same time uniformly diffused. The plants of the period were nearly all of the lands which are now confined to the tropics, in their tree-form, and chiefly consist of the cryptogamic tribes, two-thirds of the whole being ferns, which attained a gigantic size. Equally remarkable is the fact, that a uniform state of vegetation prevailed over the whole earth during the age in question — the coal plants of Melville Island and Greenland corresponding to those of Southern Europe — the deposits in America yielding species identical witli those in Great Britain ; while every fresh discovery of the useful mineral, in tlie east or west, in Russia or Australia, shows the fossil remains of the same flora, in hke gigantic forms, and in similar affluent fecundity. Hence the more probable , solution of the problem has been sought for in the disengagement and diffusion of the heat accompanying so universal an eruption of the igneous rocks, and which, as permeating every part of the crust, evinced a nearly uniform temperature over the interior range of their influence. Tlie hypothesis has likewise been adopted by geologists, that the earth, originally an incandescent mass, was gradually cooling down, but still sufliciently genial all over as to foster the excessive growth of vegetation, as well as the amazing opulence of marine animal life. But from whatever cause, the existence of a high and uniform temperature was indispensable for the sustenance of so prolific and uniform a state of living things, vegetable or animal ; the disengagement of gases, especially of carbonic, would, upon either view, be a necessary concomitant, producing vapours, showers, and rains of corresponding density; and as all these requirements, in a moist and warm atmo- sphere, are implied in the exuberant flora of the coal measures, so is there evidence in the igneous phenomena of the period that the conditions were all in full and active operation. "We learn," says Sir Charles Lyell, "from, the labours of M. Ad. Brongniartj* that there existed at that epoch, during the formation of the coal • Sistoire des Vegetaux Fossiles, 2 vols. xliv GEOLOGY OF SCOTLAND. measures, equisetse upwards of ten feet high, and from five to six inches in diameter; tree ferns of from forty to fifty feet in height ; and arborescent lycopodiacese of from sixty to seventy feet high. Of the above classes of vegetables the species are all small at present in cold climates j while in tropical regions there occur, together with small species, many of a much greater size, but their development, at present, even in the hottest parts of the globe, is inferior to that indicated by the petrified, forms of the coal measures. An elevated and uniform temperature, and great humidity in the air, are the causes most favourable for the numerical predominance and the great size of these plants within the torrid zone at present."* The vista thus opened into the past condition of the earth is no less instructive than curious. The existing kinds of plants in Scotland corresponding to those in the coal measures are horse-tail, clab-mosses, and ferns, none of which ever attain, in their stems, the thickness of an inch ; but which, as seen in the restored picture. of the ancient world, grew to the size of gigantic trees, and multiplied in such numbers as to have surpassed the rankness and luxuriance of an Indian jungle, in regions now invaded by the impenetrable barriers of the polar ice. The relics of these extinct forests, through the converting agencies and wonderfully conserving powers of nature, anddst so many convulsions of the globe, are now buried deep in the bowels of the earth, constituting the chief source of our domestic comfort, and of nearly all our commercial greatness. The mineral masses would also be much influenced by the operation of these causes. The heat, in the first place, would render them less cohesive in their texture; and, in the next place, their disruption, and the attrition necessarily occasioned by the mechanical shifting and upheaval of the earth's crust over such large areas, would as necessarily result in vast accumulations of sand, mud, and other detrital matter. As from the disintegration of the primary rocks were obtained the materials of the clay-slate, grauwake, silurian, and old red sandstone deposits, so, again, from tliese, as well as from the primary aff"ected anew by the convulsions of the period, were derived the sandstones, clays, and shales of the coal measures. . The limestone and coal are chiefly the product of organic agencies, when so much life— willed into being and sustained in such profusion by the provident arrangements of the period- elaborated the vegetable and calcareous ingredients of which the coal and limestone consist. It is less easy to trace the secondary sources of the ironstone, as, in the anterior systems, especially the old red sandstone, iron was disseminated through the mass in the state of an oxide, and as mere colouring matter ; whereas, in the carboniferous system, it exists in thick layers, in nodules, and in other concretionary masses. But here, again, a solution of the difiiculty may, to a certain extent, be sought for, in the extrication of heat and the fusion of earthy matter from the interior, when, by means of chemical action, magnetic and electric forces, a new arrangement of the metallic particles would be produced, and their aggregation arouYid an earthy basis more readily efiected. The prevailing ingredient, however, of the system is carbon, in a solid state— the residuam of the vegetaljles which consti- tute its most distinguishing feature;— and hence, as holding a position in the earth's crust intermediate between the old and new red sandstones, and both almost desti- tute of vegetable remains, it has been appropriately termed the " Carboniferous System," to mark an era so wonderfully rich in the development of vegetable life. We shall now proceed to give a more detailed account of the structure, arrauge- mentj, and constituents of the coal measures— the nature and characters of the • Principks of Geology, Vol. i. p. 116. GEOLOGY OF SCOTLAND. xlv organic remains— and the geographic distribution and economic history of the coal itself. Much as the surface of our earthly abode is worthy of admiration, in the distribution of land and water, the diversity of hill and dale, the succession of seasons, of light and darkness, its interior arrangements are no less remarkable, whereby the products of other remote ages have not only been garnered up, but so distributed and protected, by a series of contrivances, as expressive of benevolent purpose and foresight as any of the existing processes through which living nature yearly accomplishes her beneficent designs ; and as contributive, if not essential, to man's varied wants and requirements, the support and embellishment of his social progressive condition. 1. The structure, arrangement, and constituents of the coal measures. The mass of which the formation is composed consists of hundreds, or often of thousands of alternating beds of sedimentary rocks. The strata vary in thickness from the thin- nest wafer-film to fifty, or even a hundred feet ; every one of these distinct in their lamination, made up partly of different ingredients, and showing a change in the fluid, as the flux and reflux of the tide, in which tkey were deposited. Their aggre- gate thickness is from 2000 to 15,000 feet in vertical depth. These materials are all inclosed in basin-shaped hollows, contained within the area of the older rocks, and produced mainly by the convulsive movements of the porphyritic traps. The old red sandstone, for the most part, forms the sides and edges of the trough in which they rest ; the strata of the two systems are consequently unconformable to each other. The lowest beds of the formation consist generally of coarse-grained sandstone, termed by the English geologists millstone grit, and inclose a few thin seams of coal. The sandstones are scarcely distinguishable — except by their position and organic remains— from the upper series of the old red ; their colour, texture, and arenaceous ingredients are nearly the same, as seen in Dura Den, the Lomonds, and other localities along their northern outcrop. Bands of limestone, shale, ironstone, and sandstone, follow in repeated alternations. A thick, massive limestone characterises this part of the series, termed the mountain limestone, from its great elevation, and supposed to have once existed as coral reefs, raised on the bottom of shallovtf seas, and so subdivided as to form suitable compartments for receiving and retaining tlie materials of the coal. This limestone is co-extensive with the coal measures in every part of the globe, and, like the kinds and orders of vegetables which accompany them, so its mass is composed of nearly similar species of coralline and other marine molluscs. The coal itself generally occupies a central position in the group, firmly caked and inclosed between the stony strata, and yet so entirely separate and homogeneous in its qualities as never, even in its thickest beds, to contain the least admixture of foreign matter. Nature, with all her afiluence, during the carboniferous age, did not all at once heap the coally ingredients together. They are arranged into seams of variable thickness. They are removed from each other by interposed strata of other kinds of rock. Intervals of time, longer and shorter according to their dimensions, would thus elapse betwixt each successive deposit. And yet so wonderfully exact had she conducted her processes, attempered her forces, prepared, accumulated, and arranged her materials, that the vast compound mass never in a single instance has been permitted to interfere with the purity and texture of the useful mineral. Not a fragment of rock, amidst the myriads that must have been rolled about, nor a chip of sandstone, nor a broken ledge oi limestone, is found imbedded in the coal, from one end of the basin to the other. zlvi GEOLOGY OF SCOTLAND. The lower as the upper surface of every seam, the commencement as the close of the bituminous deposit, preserve throughout their distinct lines of demarcation, unmixed at every point of contact, above and beneath, with the enclosing materials. The varieties of coal— as anthracite or blind coal, cannel or parrot, and the common house or glance-coal— are occasioned chiefly by the different proportions of the combustible elements that enter into their composition. The coal metals of England, as compared with those of Scotland, are of a greater average thickness, consist of a greater number of seams, and are generally of a richer quality, from containing a larger proportion of bitumen. , The great coal-basin of Scotland, in which all these materials were collected, occupies the central division of the island from sea to sea. The northern out- crop of the lower beds meets the eye, along the ridge of which the Lomonds con- stitute the highest point, ranging eastward by St. Andrews to Fifeness Point, and extending westward by Dollar, Stirling, the Campsie Hills, Glasgow, Greenock, to the coast of Arran. The southern lip of the basin stretches from the German Ocean, near Dunhar, by the Lammermuirs and Pentlands, to the Ayrshire coast on the North Channel. The smaller basins of Berwick, Roxburgh, and Canouhie are separated by the great silurian range, or back-bone of the border counties, and are as much connected with the English as with the Scottish coal measures. To the lover of the picturesque, as well as the geologist, the manner in which the strata are arranged at Penton Bridge, in the bed of the Liddle, will furnish a study of the most interesting kind. An injection of trap has thrown up the coal metals, shaped and moulded the limestone into every form, here broken into large tabular masses, there projected into lofty vertical walls ; in one quarter twisted, into long zig-zag ridges, and in another gently bent into domes and arches of every size and variety; some of the bands are a mere aggregation of encrinites, and others are inscribed all . over with shells, entire and perfect as the existing races, '' forms of creatures in old worlds." A concretionary ironstone, full of brick-red nodules, and thin dark- coloured shales, give additional variety to the picture. The windings of the river, the banks on the Scottish side gently sloping, and thickly covered with coppice- wood, and, on the English side, forming a precipitous wall of nearly a hundred feet in height, serve to render the scene, with its various adjuncts, one of singular beauty, and perhaps unrivalled as a display of geognostic masonry in ruins, on any similar scale of magnitude. We here see part of the inner framework and machinery by which, through the action of the trap, the great extended mass has been divided and arranged anew into workable sections. Thus, over the area of the great coal-basin, bounded north and south by the older trap formations, a group of hills appears, isolated and thrown up as if at random, and nearly all of a conical wedge-top shape. These hills, in the eastern and central division of the coal-field, are the Lomonds, Cults, Largo, and Kellie Laws, North Berwick Law, Arthur's Seat, Corstorphine, Castle- rock of Stirling, Cleish, Binnarty, and the Bin-range at Burnt-island. From the character of the strata, and other phenomena accompanying the elevation of the igneous rocks, it can be clearly shown that the period of their ejection was subse- quent to the deposition of the coal-metals, which have been altered when in contact by their heat, and shifted in position for considerable distances along their line of section. The traps of the Campsie Hills belong probably all, or in part, to the same period of eruption, being identical in mineral qualities, overlying or everywhere dis- persed among the coal-metals. The associated strata, sandstone, limestone, shale, and GEOLOGY OF SCOTLAjSTO. xlvii ciiiy iroa-scone, are found at various points of elevation tlirough the range, wliicli is twenty miles in length, ten in breadth, and rises in Meikle Ben to nearly 2000 feet above the level of the sea. The coal is wrought in various places along the eastern, southern, and south-western declivities, in the parishes of Larbert, Kilsyth, and Campsie. The metals are sometimes extracted from under a roofing of trap, spread- ing over considerable extent of surface ; and there is little doubt that the stone-flood has poured over, and now conceals, large areas of coal in the district. The injection of so much igneous matter among the coal-metals may appear, at first sight, to have led only to inextricable confusion, and to have been destructive rather than otherwise. There are waste and disturbance, doubtless, and sometimes upon a considerable scale j but observe a little closer, and in these very disturbances we discover the most unequi- vocal testimony of an overruling intelligence and a restraining hand guiding all to a determinate purpose, and rendering conveniently accessible the inclosed treasures of . coal, iron, and limestone, which are always associated or found in the closest juxtaposition. Examine any coal-field in your neighbourhood, and observe, first of all, the place of the mineral. The coal does not lie exposed on the surface. The consti- tuent elements are such that by exposure they would speedily have run to waste. Even a thick covering of earthy mould would not have been sufficient to protect it ; and, therefore, was the treasure purposely hid in the ground, and so enclosed that the floods could not wash it away. Then consider the quality of the rocks by which the coal is protected : these are not the granites and hard crystalline masses of the primary formation, through which no borings could have been made, and among whose compact substances drainage would have been impracticable. A more suit- able series of limestone, sandstone, shale, clay-ironstone has been established around the coal-metals, at once affording a safe roofing to the mine, and an easy outlet for the water, and all in themselves so valuable and indispensable to man. Next observe the elevated and inclined position into which the coal strata have been thrown. Had they remained horizontal, as originally deposited, and covered with the vast accumulations spread above, the depth of the metals would have been utterly beyond the industry of man to have reached. Hence the molten floods of trap injected amidst them, whereby the seams are divided into workable sections, — the great basin broken into limited areas, — a level prodiiced for draining the mines, and, instead of being plunged to inaccessible depths, the several beds are repeatedly dislocated, and rise like the steps of a stair towards the surface. Again, every coal-field is furnished with a system of checks, in the shape oi faults or dykes against floodings, fire-blaze, and the accidents that occur in the operations of mining. These, formed of the detritus of the associated rocks, or of intruded whinstone, present the appearance of a vertical wall, cutting the seams at right angles, and, though often occasioning inconvenience and interruption, yet, as every experienced miner well knows, form upon the whole his greatest safeguard, and are essential every way to his operations. To all which add, as constants in every coal-field, the minerals of lime and iron, gifts both of them of inestimable value — the former in the enriching of the soil and the construction of our dwellings, the latter ductile and plastic as wax, and convertible into so many useful purposes ; and the coal also there, as if purposely to assist in the reduction of the ironstone and limestone into their various economic proportions. When read aright, one cannot fail to see in all this elaboration of materials, arrangement and disposition of parts, quality and character of strata, and vast in- xlviii GEOLOGY OF SCOTLAND- exhaustible stores of mineral treasures, the most indisputable evidences of consum- mate wisdom, marvellous foresight, and benevolent design;— all conspiring to call forth our admiration and gratitude, as they cannot fail to reward the most diligent study of the varied contents of this remarkable storehouse of ancient relics. While in the repetition of the different strata, we see the successive deposition of earthy substances of different natures, afterwards consolidated, the number of the calcareous beds, no less than the alternation of the vegetable strata with the laminBe of the shales, show that successive generations of animals, as well as plants, had followed successive depositions of earth.- To the same circumstances of repose, the solution of soluble earths and metals, pressure, and heat, we must attribute equally the consolidation of the rocks and the conversion of the vegetable deposits into coal. Conceive now the altered con- dition and quiet statical arrangements of all within these stony chambers since the coal measures were forming, and their basins were collecting their rich bitu- minous treasures. Where now the lands that maintained the mighty forests which filled them ? where the rivers that transported their daily loads of drift-wood ? where the lakes, estuaries, and seas into which were poured their bounteous waters ? The continents of the period have disappeared. The land and sea have interchanged places. The coral reefs of ocean are elevated hundreds of feet over the fresh green earth. And no fact is more certain, or more easily to be demonstrated in the whole science of Geology, than that every rock, stratum, or layer of indurated matter — hundreds in number in every coal-field — on which there is impressed the figure of a plant, the form of a fish, the curvatures of a shell, or the outline of any organic thing, once constituted the bed of a sea or lake, the floor of the waters ; replaced and covered over by another layer of rock, then by another, and another of still differing and altering ingredients, and now alllifted up and piled mountains high on the dry land. The most curious thing is, that the organic remains of the coal are all of terrestrial origin, while those of the limestones are all as unmistakeahly of marine origin. The limestone and coal-beds alternate with each other, seams of coal lying beneath the lowest calcareous deposit, and limestone strata of varying thickness repeatedly intermixed with the bituminous series. There is one bed of estuary limestone which traverses the coal-field betwixt Petty cur and BurdiehousBj cropping out at various intermediate places; it is termed estuary, because marine and terrestrial remains are found together in the mass, land plants," marine fishes, and shells, confusedly intermixed. But the exception only serves the more to establish the general conclusion concerning the origin of the whole carboniferous system, whose materials were collected during the subterranean movements by which the earth's crust was so much affected, and the recur- ring oscillations by which the floor of the waters was alternately depressed and upheaved. Twelve hundred feet on the slope of the Lomonds, or high up among the sources of the Nith, near Cumnock, and we tread the shores of a former sea, the shells, corals, and drift-leaves, all imbedded in its sands, and all still as perfect and beautiful as when washed and stranded up by the last ripple of its waves. Thus — " Earthquakes have raised to heaven the humble vale, And gulphs the mountain's mighty mass entombed, And -where the Atlantic rolls, fair continents have bloomed, — i3 iot to be regarded as the mere exaggerations of the poet, but the warrantable deductions of the man of science. GEOLOGY OF SCOTLAND. xlis 2. The nature and characters of the organic remains. As the whole mass of the coalis now universally considered to be composed of vegetable matter, so in like manner all the limestones of the formation are regarded as mainly consisting of animal matter, either secreted during the exercise of the living functions or the petrified remains of their bodies. The nature of the flora of the period is best defined on the thin bands of the shale and other accompanying strata, although not so perfectly preserved as the skeletons of the fishes, or the testaceous coverings of mollusca found iu the limestone and other rocks. It is rare, for example, to meet with the flower and seeds, those parts upon which the distinction of species and their classification chiefly depend ; but still, the portions which remain often possess very great distinctness and beauty, and many specimens of wood are so exactly pre- served, that the tissue may be distinguished under a microscope as complete as in recent species. The coal, when beat with a hammer, gives the woody sound, and, analysed by the chemist, its ligneous qualities are fully tested. The class, order, Bometimes the precise genus, as compared with existing families, may be ascertained to which a fossil vegetable belongs, even when we detect only a small fragment of the plant. More frequently these fossils bear an analogy to some recent kinds, which they closely resemble, but to which they cannot be accurately referred. The class and order, however, are generally determinate ; and, proceeding upon their established and well-defined characters, the botanical history of the coal-field, though the families or individual kinds be few in number, while vast in productiveness and geographical range, supplies materials for ascertaining several truths of liig'h interest. Between three and four hundred species of plants are now enumerated as belonging to the coal measures, not one of which is marine, and most of which are allied to the tropical tribes of palms and ferns. Experiments have shown that the vegetable matter of these tribes is the most capable of resisting solution in water. The wood of other kinds, of the dicotyledonous order, and of a harder texture, is ascertained to be more easily soluble ; and hence the presumption is, that, under the conditions necessary for the formation of coal, many kinds have disappeared, being entirely decomposed, and that, therefore, the flora of the car^joniferous era was richer and more varied than the fossil remains indicate. According to the arrangement of botanists, there are two great divisions of plants, termed cellulares and vasculares, the former flowerless, and hence called cryp- togamous, the latter bearing flowers, and called phonogamous. As connected with a greater simplicity of structure, the cellular plants are destitute of spiral vessels, while those of the vascular class are all possessed of them, as well as of a complex system of tissue. By another subdivision, these classes are denominated endogenous and exogenous, according to the nature of the stems, whereby the one receives its increments of growth all on the interior, and the other on the exterior parts of these organs. The seeds, again, of these natural orders, are very diff'erent, and, according as they are one or two-lobed, the distinction arises of their being monocotyledonous or dicotyledonous ; the seeds of palms, corns, and grasses are of the former structure ; those of our garden fruits, as apples, belong to the latter. The cryptogamic orders, as ferns, club-mosses, and horse-tails have no true seeds, and they are, in conse- quence, acotyledonous^ whose germinal organs are as yet but little understood. i It'would be wrong to interpret these divisions aiid forms of vegetable structure aa, in the least, indicative of a lower or a higher, a less or a more perfect system of parts. Bach is as perfect as the other, after its kind. They are so constructed, h I GEOLOGY OP SCOTLAND endowed with different kinds of organs and arrangement of vessels, as to become most adaptive to their several conditions in the great economy of things. Their law of vegetable existence is never violated. There is no transmutation, beyond well- defined limits, of one type into another; and from apparently the more simple to the more complex, the fossil remains imbedded in the rocks clearly demonstrate that size and development are terms of no meaning, when applied to a low or a high type of organisation. The cryptogamia of the old world, the earliest planting in the new-formed soil, are in bulk, as in elegance and beauty of form, unrivalled by the finest specimens of modern arboriculture. The little and the great, the extinct and the recent, were equally the objects of Nature's maternal care, and were all modelled with a skill and finish that left nothing to be supplemented. Of the existing species of British algas, while some consist of microscopic forms, inhabiting obscure places, shady paths, or half-immersed surfaces of stones and banks, " the more complete algse," says Dr. Greville, " comprehend species forming sub-aqueous forests, of considerable extent, in the vast ocean, emulating in their own gigantic dimensions the boundless element that unfolds them. Chorda filum, a species common in the North Sea, is frequently found of the length of thirty or forty feet. In Scalpa Bay, in Orkney, according to Mr. Neil, this species forms meadows, through which a pinnace with di£S.culty forces its way. Lessonia fuscesscens is described as twenty-five or thirty feet in length, with a trunk often as thick as a man's thigh; but all these, and, indeed, every other vegetable production, is exceeded in size by the prodigious fronds of macrocystis pyrifera — the sea-weed reported by navigators to be from 500 to 1500 feet in length; the leaves are long and narrow, and at the base of each is placed a vesicle filled with air, without which it would be impossible for the plant to support its enormous length in the water, the stem not being thicker than the finger, and the upper branches as slender as common pack-thread."* The presumption is, that the algse of the most ancient geologic times were, according to analogous instances, of still greater dimensions and nice elaboration of functional organs ; while, as to the animal life of the period, for intricacy, minuteness, and division of parts two instances may be given only, namely, the encrinite, and pentacrinite, one individual of the former being made up of no less than 30,000 separate plates of stone, and one of the latter containing 150,000 minute pieces of the same material. It was soon observed, when the study of fossil vegetables began to attract the attention of botanists, that those from the coal measures were distinct fi'om the plants now existing on the surface of the earth, and that, in their general aflBnities, they more nearly approached the species of tropical climates than such as grew in the temperate zones. Subsequent researches have shown that the species imbedded in different formations likewise differ fi-om each other, and that from the lower to the higher systems, according to their order of superposition, the genera and species become numerically greater. As already related, they first appear in the schists and limestones of the silurian strata. These contain a few cryptogamic species, about thirteen, of which, according to Brongniart, four are marine algse, and the rest ferns, or the allied orders. In the coal itself, above 300 distinct species have been recognised, among which the ferns are the most abundant, amounting to aboiit two-thirds of the whole. Many of them are arborescent, with large branching fronds, and their roots, with portions of their trunks standing vertically, are still • Greville's AlffcB Britannicee. GEOLOGY OF SCOTLAND. U found in the spots where they grew. A considerable number of palms, a few club-mosses, and grasses, are the chief monocotyledons; and there are several dicolyledons, -which have been considered analagous to the families apocynse, euphor- bacise, cactse, and coniferse ; along with numerous plants, the exact nature of which is extremely doubtful. The FELICES, or ferns, constitute the most numerous of the cryptogamic plants of the coal measures. They indicate a state of the atmosphere, and represent a condition of the earth's surface, stretching from pole to pole, and embracing the extremes of longitude, with which no after period of the planet's history can be compared, and of which, upon physical grounds, no sufficient explanation has yet been given. The circumstances most favourable to the growth of such plants are humidity, shade, and heat. The number of species found in the coal formation are now upwards of two hundred, to which list additions are yearly being made; most of them of forms differing much from those of living ferns, and nearly all belonging to the tribe of polypodiums, which are chiefly allied to the existing arborescent species of the tropics. The trunks and stems of these arborescent species are deeply decorticated, and indented with seams, the markings of their deciduous fronds, and by which they are distinguished from those of all monocotyledonous plants. The whole superficies of the globe was one dense forest of fern trees. A uniform condition of temperature, moisture, and soil everywhere existed to maintain their exuberant fecundity, which partook of the same specific development in all latitudes. Admit one, or any number of centres of generation, and the diffusion and the multiplication of the race are utterly unprecedented; and show that the carboniferous era is, in all its circumstances and peculiarities, a marvellous and yet unexplained page in the earth's history, as it brings before the imagination a vista of the ancient world with which no arrangement of landscape or combination of scenery can now be compared. The tree . " whose seed is in itself," God commanded everywhere to flourish. While the earth was still unpeopled it sprang up luxuriantly, to be again buried in the ground. Man digs from it his daily fuel, and, obeying the law of his multiplication, the earth is replenished and subdivided, mainly through its instrumentality, as the promised in- heritance of his race. " It is, indeed, a curious reflection," says a recent writer, " that the present commercial greatness of Britain should be intimately connected with the towering and thickly-spread forests of arboraceous ferns and gigantic reeds, vege- tables of strange forms, and uncouth names — which flourished and decayed on the surface of the earth, age after age, during the vastly-extended term of the carboni- ferous period — ere the mountains, in many masses, were yet upheaved, and while as yet there was no man to till the ground ! Yet such truths Geology teaches us, and of such curious facts the very coals at our sides, and in our parlour grates, remind us." * The EQUisETACB^, known as the cdmmon horse - tail of our swamps and ditches, are likewise very widely distributed through the coal measures. The existing species are indifferent to climate, extending from Lapland to the torrid zone. The fossil ones were equally independent of latitude, being found of the same gigantic size in all the coal strata. They are divided by Brongniart into equisetse and calamites, so named from their jointed, reed-like structure. The latter kind are more abundant in a fossil state. They are characterised by large and • Our Coal-Melds. By a Traveller undergroxind. IH GEOLOGY OF SCOTLAND. simple cylindrical stems, articulated at intervals, and sometimes marked by verticil- lated branches of great size. Lepidodendka, including the lycopodiacea, or club- moss tribe, and other plants of similar structure, are, after calami tes, the largest, and most abundant class , of fossils in the coal formations of the North of England, occurring from twenty to forty-five feet long, and occupying large spaces in an upright position. In some points of their structure they have been compared to conifers, or the pine family, and in the general aspect of the stems ; to ferns more especially, in the abundance of axilar ducts contained in the axis, and in the want of several apparatus ; and to mosses in their whole appearance. By means of lepido- dendron a better passage is established, according to Lindley and Hutton, from flowering to flowerless plants, than by either equisetum or cyeas, or any other genus. SiGiLLARiA, very common in the coal formation, constitute a group of plants unknown in modern vegetation, and of which the dm'ation seems to have been limited to that particular era. They abound in the sandstones and shales that accompany the coal, and, being apparently hollow in the stem, the fossil specimens are generally filled with sand or clay, surrounded by an outer bark, beautifully fluted with longitudinal parallel grooves. M. Brongniart enumerates forty-two species of sigillaria, and considers them to have been nearly allied to arborescent ferns, with leaves very small in proportion to the size of the stems ; while Lindley and Hutton show strong reasons for classing them with dicotyledonous plants, entirely distinct from ferns, and different from any plants in the existing system of vegetation. This tree grew to an enormous size, specimens of four feet in diameter by fifty feet in length being frequently met with ; traces of a vascular and fibrous structure can be observed in the trunk ; also, the annular wood-layers are sometimes beautifully defined ; and, presenting a coating of bark of an inch in thickness, the probability is that the sigillaria belonged to the exogenous order of vegetables. The stigmaria, equally abundant in the coal measures, are perhaps still more obscure in their botanical relations. The trunk of this tree is dome-shaped, of three to four feet in diameter, and the branches, some of them, supposed to have been from twenty to thirty feet j . their leaves, by Steinhauer, have been traced to the length of twenty feet, and have been considered to be much longer. The stems and branches are covered with spirally-disposed tubercles, resembling the papillee at the base of the spines of echini; and from each tubercle there proceeded a cylindrical, and probably a succulent leaf, whose scars ,])enetrated through the bark, and rendered the smfaces on both sides slightly corrugated. The form of the trunk and branches, which are always flattened, show that these trees could not have risen vertically in the air, but must either have trailed on the ground or floated in water. There, is a very remarkable fossil, described by Count Sternberg, with branches attenuated tipwards, and having the whole surface covered with leaf-bearing scales, arranged in an imbricated manner, neither referable to the genus Yucca nor to that of Cactus, to which he has given the name lepidodendron dichotomum. This plant, like ferns, as well as many of the preceding kinds,, is furnished with a singular structure of organs subservient to respiration, and highly adapted for inhaling nutritious juices from the atmosphere. It is well known that the cacti, and most succulent plants, derive their nourishment more from their relations to the air than to the earth. The «/mcc«, now so common in our gardens, and the lychnaphora, which choose, fpr their habitation a dry sandy soil that has undergone little prepara- tion from the decomposition of previously existing vegetables, were pecuUarly adapted for clothing a, recently formed world much warmer than the present. By GEOLOGY OF SCOTIjAND. liii sucih plants, vegetable matter would rapidly accumtila-te to the exteiat tbat we find in our coal strata, when the land abounded in moisture, and the air was densely charged with carbonic acid. Favularia, Megaphyton, Bothrodendron, and TJllodendron belong to the same group of plants with the sigillaria, and all exhibit a similar disposition of scars, arranged in vertical rows. In the three first genera the scars appear to have given origin to leaves, and in the last they indicate the insertion of large cones. The Asterophyllites, so called from the stellated arrangement of the leaves round the branches, are possessed of many of the characteristics of these imperfectly under- stood families; there are no traces of them found among existing vegetables, nor in any strata more recent than the carboniferous series. But still these, as well as all the others, are connected with living tribes by common principles of structure, and by details of organisation which show them all to be parts of one grand, consistent, and harmonious design. But of all the fossil plants found in the coal measures, the coNiFERiE, or pine tribe, distinguished by their punctated woody structure, are the most interesting, whether we Consider their characteristic properties, extensive distribution, age, and consistency of habit through all the epochs and changes of the earth's history. Unlike the tree ferns already noticed, the pines grow now as they grew before, inhabiting the same latitudes, and preserving the same appearances in bulk and figure. The coniferse occupy a place intermediate between the classes of the cellu- iars and va,sculars, connected with the former through the lycopodiums, and with the latter by the myricese, or aromatic gale tribe. The scales of the cones are regarded by botanists as true foliage or reduced leaTcs, and in this respect they approximate to the genus zamia, of the order cycadeae, where these organs are dis- tinctly developed as carpellary leaves. Thus widely connected through the chain of vegetable life, the fossil pines, discovered in the coal strata, form also the most interesting link between the present and the remote past, showing similar conditions of vegetable existence and forest landscape. No class of plants have been more useful to man than the whole pine family ; none are more universal in their distri- bution over the face of the globe ; none are possessed of such powers of endurance, existing through all time, and natives of every part of the world, from the perpetual snows of arctic America to the hottest regions of the Indian Archipelago. These trees differ as remarkably in form as in size, ranging through every gradation, from the stunted juniper of the Grampians to the stately cedars of Lebanon ; and the fossU specimens do not excel the existing races. The araucaria, or Norfolk Island pine, attains a height of two hundred feet and upwards; and, in the Oregon territory of North -West America, there are species of the fir tribe (P. Lambertiana and P. Douglasii), which rise to even still more gigantic proportions. Among the largest fossil specimens are those of Craigleith and Grranton, in the neighbourhood of Edin- burgh, which were lately found in the sandstone deposit, and measured about forty feet in length by nearly five feet in diameter, but were only fragments of their original dimensions. ■ Figuratively, it is said of the cedar, that its branches shall cover the earth, and in the shadow thereof all fowl of every wing shair dwell. Literally, we find that members of the same family have existed in all lands, and flourished in the mountains through all ages. Our fire" are now supplied with billets from the modern pine forest, growing in the vicinity, or over the very wreck of ancient submerged lands, and along whose borders waved the extinct forests of geologic times, which furnish fuel to all the- families of maiij and encourage the arts in all quarters of the globe. " liv GEOLOGY OF SCOTLAND. If we seek for anytUng analogous in the present condition of things, New Zealand furnishes some of the most striking points of resemblance betwixt the flora of the old and the new worlds. In that recently discovered land, the number of species of plants already described is about 632, of which 314 are dicotyledonous, and the remainder monocotyledonous and cryptogamic. The fern tribe is the most abundant, covering, in the tree size, immense districts. They replace the grasses of other countries. Plains and mountains are everywhere filled with them, growing to thirty and forty feet in height, and giving their sombre hue of colouring to the landscape. The variety and elegance of the arborescent species are remarkably striking, recalling to the numerous emigrants who visit these distant shores the strata of their fatherland, when Nature was storing up materials, in the remote ages of the past, for colonising and facilitating the intercourse betwixt the remotest ends of the earth : when the mountains of Caledonia, now covered with the braken, which scarcely conceals and cannot compare in stature with the branching antlers of the red deer, were mantled in forests of tropical characters, and which attained to a size and elevation of more than tropical dimensions. The formation of coal from these vegetable bodies is now a matter, among geologists, which admits of no dispute. Their growth, distribution, and uniformity of character must be regarded as the results of peculiar causes. That the principal beds are of a single period, formed of the same class of vegetables, proves that the causes by which they were generated acted only during that epoch. That they are dispersed all over the globe, in areas of variable dimensions, proves farther that the physical agents concerned in their production must have acted on the vegetable matter, and its conversion into coal, with far greater intensity, and on a much grander scale, than any of the geological causes that are still efiecting changes on the earth's surface. That the vegetables were collected into basins, and into stratified beds or seams, by the abrasive action of water, are points on which all are equally agreed. There are differences of opinion as to the con- ditions under which the coal resulted, the chemical agencies concerned in the process, and the mechanical powers that assisted in the collection of the materials. It is held by one class that all the vegetables grew where the coal lies, and by another, that they were transported from a distance by rivers and- currents. That the materials did not all grow on the spot is apparent from the immense bulk required for beds that are of any considerable degree of thickness, as well as from the fact, that the portions of which the bottom of the mass was formed exhibit no more marks of having undergone decomposition or decay than that which lay at the top. The traces of stems, branches, and leaves, are as distinct and per- fect in the lower divisions of the strata as at the centre or surface. The whole, therefore, of which a layer was constituted must have been very rapidly deposited; and, from the extreme delicacy and beauty of preservation of some of the organic forms, the forests which supplied them must have grown at no great distance. Many trees, indeed, with their roots and stems, are to be found in every coal-field, standing in their original vertical position, and penetrating several distinct strata of sandstone and shale, as well as of the coal itself. In these cases the fact is certain, not only as to the place of their birth, but as to the intensity of the causes which effected so rapid accumulation of materials around their still unbroken, undecayed forms. The transformation of the vegetables themselves into coal has been variously explained upon chemical principles. The most probable account of it is, that GEOLOGY OP SCOTLAND. It durin" their submersion the plants have suffered that slow kind of decomposition by which the greater part of the vegetable principles have been evolved in new combi- nations, while the carbon, and a portion of the hydrogen, have remained. This residue, mixed with more or less of earthy matter, deposited at the same time from the waters, has in its soft state been consolidated by the force of aggregation, and under the strong action of the heat of the period assisting its more rapid decomposi- tion, has formed the bituminous product of coal. It is well known that wood, by immersion in water, becomes first brown, and then black ; and the ligneous fibre, by slow decomposition, or more rapid, according to the state of the climate, is com- pletely converted into a black mould, in which carbon predominates. Hence it is easily conceivable, that this process, being carried on under different circumstances, may proceed with various degrees of rapidity, and to a greater or less extent; and hence, likewise, will originate different varieties of coal, some being much more carbonaceous, some more bituminous, than others, while their composition will be also varied by the different quantities of earth deposited during their formation. The purest coal would be the most quickly formed ; and as few of the ashes of any coal are mixed with particles of clay or sand, the presumption is, that the whole chemistry of the process, and all the mechanical forces engaged, were special, unpre- cedented, and never repeated under the same combination of circumstances. The analogy to peat, in the formative process of coal, is maintained by some, especially by Dr. M'CuUoch. His illustration is curious. " By the action of water," he says, '' on the vegetable matter, a portion of the hydrogen is dissipated, and the result is a new compound of hydrogen and carbon. It is not unlike that produced by fire, of which roasted coffee is an example. Thus the papyri of Herculaneum have been roasted, or carbonised by water, not by fire ; they are in a state of peat. The exact nature of this change is easily ascertained by chemical analysis. There is here an approximation to the condition of bitumen, and thus to coal ; but it is no more. When forests, or peat of far higher antiquity, are found at greater depths in the earth, the bituminisation is well marked, though still incomplete. The antiquity is proved by the strata that lie above, and the substance is then lignite, including Cologne earth, Bovey coal, and jet. This substance may be considered a mixture of peat and coal, or a transition between the two, retaining the vegetable forms. The last change is to coal. This, in a similar manner, is proved to be a substance of far higher antiquity than lignite ; and that such is its origin is also proved, geologically, by the exact resemblance of its disposition among the strata, to that of peat among beds of sand and marl, and by the certainty that it has been formed under fresh water, and in marshes, as it contains only fresh water shells and terrestrial vege- tables. It is proved, chemically, because, by mere change of form, jet becomes coal."* Anthracite, or blind coal, is generally found in veins, of small size, and traversing the rocks of nearly all ages ; certainly in granite, gneiss, the trap of the Carlton Hill, Edinburgh, as well as in the coal formation in various places in England, Wales, near Cumnock and Kilmarnock in Scotland, and at Kilkenny in Ireland. In America it is found covering large areas, near Pittsburg, and other localities in Virginia. From its analysis, it does not appear to contain any bitumen, its chief ingredients being carbon, silex, alumine, and oxide of iron, and hence, by mineralogists, anthracite is not referred to a vegetable origin, but, like plumbago, • Western Islands. Vol. iiL p. 121. ki GEOLOGY OP SCOTLAND. ■which is usually fouad in similar situations, it is supposed to be the product of such agencies as elaborated and arranged the particles of other compound earthy and metallic rocks. The Carboniferous Limestones chiefly owe their origin to the prolific abund- ance of the marine animal life of the period, as the coal unquestionably does to that of the terrestrial vegetables. There is great difficulty in admitting this conclusion, at first sight, when one considers the vast quantity of limestone contained in the coal measures. Some of the beds are several hundred feet thick, consisting often of 96 per cent, of pure carbonate of lime. There is a repetition of beds of varying thickness, occurring in every quarter of the globe, and always co-extensive with the size and form of the coal-basins. Through their whole extent in Scotland, England, Wales, and Ireland, the mountain limestone strata are invariable accompaniments, lining generally the outer edges of the basins, and following the direction and line of bearing of the coal metals, but not unfrequently traversing them at right angles, and thereby dividing or separating the basins from each other. In America, where everything is on a vast scale, the limestone covers an area of many thousand square miles, stretching from the Atlantic to the base of the Rocky Mountains, and filling with calcareous matter nearly the whole immense interspace of the Central States.* This limestone, wherever found, possesses a general uniformity of character, com-- pact and thick in the mass, and, for the most part appears to be -composed of organic remains. When apparently more homogeneous and destitute of organisms, the microscope has shown that these are often more profusely distributed through the mass of the rock, the mineralised skeletons being as fully developed and per- fectly preserved as those of a larger and thicker shelly texture. The rock is occasionally of an oolitic structure, and sometimes contains parts of encrinal columns, in such abundance that the mass is, in a great measure, made up of them, whence the name Encrinal Limestone. Along the northern line of the outcrop in Fifeshire, it everywhere abounds in these organisms — from St. Andrews, by the Cults, Eorther, Lomonds, Binnarty, and Cleish-hill quarries. An inner range of the deposit occurs on the south of Largo Law, at Innertiel, Inverkeithing, North Queensferry, Rosyth, and Charleston, where the deposit is often nearly a hundred feet thick, and filled with countless multitudes of shells and corallines. The coralloid remains consist of several genera, as caryophylea, turbinolia, astrea, favocites, tubipora, and retipora. These are the most abundant; but, in all, upwards of thirty genera, and about seventy species, have been found in the carboniferous limestone; while, of the families of Crustacea and testacea, more than a thousand species have been detected in the formation. It was * " One of the most remarkable geological features of this continent is the vast extent of the carhoniferous limestone. I have traced its eastern border — conforming to the course of the other mineral formations east of the Mississippi— more than 1,000 miles, running to the west of south, fW)m the state of New York to the thirty-fifth degree of north latitude, in the state of Alabama ; the course is there changed, and lies to the north of west, leaving Little Kock on the Arkansas about thirty miles to the south, and disappearing between 500 and 600 miles from the Rocky Mountains. This deposit extends uninterruptedly a geographical distance of at least 1500 miles from east to west, underlying portions of the states of New York, Pennsylvania, Ohio, Indiana, Illinois, Missouri, and the territory of Arkansas on that line. In Tennessee, Kentucky, "Virginia, and Maryland, it is bounded by a line, of which the Cumberland mountains form a part. In the pkins through which the Mississippi flows, and which include the lUinois prairies, it appears like a continuous floor, forming an almost unvarying &a.t."—Featherstonhaugh's Geological Report, GEOLOGY OF SCOTLAND. Iva remarked of the vegetables of the coal strata^ that their geographical range was co-extensive with the circumference of the globe, — that the same species were com- mon to America and Europe, to Melville Island and Australia, — and that the types of them, -which still exist, are in their larger forms all confined to tropical countries, ■while in northern latitudes they are represented by diminutive herbaceous plants. The same law of distribution seems likewise to be maintained betwixt the extinct and existing races of the animal remains, as represented in the carboniferous lime- stone, more especially with those of the coralloid order. The living families of corallines, in their full and active development, 'are now only found in the Pacific and Indian seas, where, in all nearly corresponding latitudes, they swarm in countless myriads, are possessed of the same habits, and are still employed, as were their congeners in the old world, in piling up coral-reefs, — vast islands of limestone rock. The extinct genera were spread over the terraqueous globe, are found in the lime- stones of all countries, in Greenland and Australia, and swarmed in such numbers as to compose entire beds of limestone. And as with the existing vegetables, so with the existing animals. Several kinds of polypi, of the orders of millepore and cellepore, are still to be found in the North Seas, and one genus of the latter family, namely, the hydra or polype, is common on the shores of Greenland, which in several of its species likewise inhabits the Mediterranean and Indian Ocean. But in the cold regions their habits are different. They build no reefs, and like all zoophytes along the coasts of Scotland, where iu many beautiful and diversified forms the order abounds, they live in a cellular tissue, reared on a single slender stem attached to stones. Thus persistent, in one remarkable direction, has Nature been, through all ages, in her structure and distribution of vegetable and animal life, demonstrating that, as the temperature of countries and epochs has changed, so in size, form, habit, and fecundity have her living tribes in both kingdoms, been altered and modified. It is still a question among geologists, whence the source of all the calcareous matter of which these limestones are composed? The opinions are various, and some of them as novel as they are untenable. Eecent writers on Geology, in. America, consider the formation to be of igneous origin, and to be unstratified even.* Others regard it as cast out in a powdery state from submarine volcanic foci, and spread over areas, greater or less, of the sea-bottom by the action of currents and other causes, when the shells and corallines became entangled in the mass. The opinion has also prevailed that the whole has been derived from the destruction or waste of the primary rocks; while others, and they are a very numerous class, maintain that it is the result of animal secretion from the waters of the ocean, where, existing either in its elements or suspended in combination, marine animals possess the power of elaborating the lime into concrete rocks and coral reefs. With regard to the two first views, there can be little doubt that the interior of the earth contains, in its vast storehouse of primary materials, lime in sufficient quantity for forming any extent and depth of limestone rock established on its surface. But many reasons could be assigned against either of these being the mode in which the deposit was formed, or the manner in which the animal remains became incorporated with the mass. Nor can we well seek for a solution of the difficulty in the waste and debris of pre-existing calcareous rocks; for, as far as our • Dr. Enunon's Geology of the Second District of New Yorh, p. 38. l^ GEOLOGY OF SCOTLAND. knowledge extends, such rocks are of comparatively limited extent among the primary series. The beds of limestone in the grauwake and silm-ian groups greatly exceed those discovered in the older strata. They are still more largely developed in the carboniferous system, while, as a general principle, it may be farther held, that the calcareous matter is more abundant in the several systems above the coal measures .than in those which are beneath them. The learned have not yet determined whence the saltness of the ocean is derived, nor how, after so much evaporation, it is always maintained at the same degree of saltness. So with the secondary cause or derivative source of the calcareous matter on the dry land, or in the waters of the ocean, whence generation after generation, epoch after epoch, marine animals have derived their sustenance, their shelly coverings, and the matter of the rocks in which they find their shelter — and, finally, their tomb ! Doubtless, what is carried into the sea, and there dissolved, will be formed anew into strata, whether by mechanical or organic agencies; and, as geology pretends not to solve all the mysteries of nature, her discoveries in this field of research, in simply detecting the mode of formation, and the analogy betwixt the organic constituents in the new and the older limestone rocks of the earth, may be reckoned among the most interesting and marvellous revelations of science. The history of coral reefs at present constructing in the southern hemisphere, under the active instincts and exhaustless energies of these puny architects of nature, is of vast importance in a nautical as well as scientific point of view. The extent of such structures is prodigious. The incredible rapidity with which they are executed is equally striking. Within a certain oceanic belt, and with no limits as to longitude, they rise in every part of the astonished mariner's track, now startling him with the form of a new island, now interrupting his course with their long line of breakers, now entangling him in meshes of reef, through which with difficulty he can thread his way. " It is not," says Darwin, in his interesting account of the Keeling Islands, "that the ocean spares the rock of the coral: the great fragments scattered over the reef, and accumulated on the beach, whence the tall cocoa-nut springs, plainly bespeak the unrelenting power of its waves. Nor are there any periods of repose granted. The long swell, caused by the gentle but steady action of the trade- wind always blowing in one direction over a wide area, causes breakers, which even exceed in violence those of our temperate regions, and which never cease to rage. It is impossible to behold these waves without feeling a conviction that an island, though built of the hardest rock — let it be porphyry, granite, or quartz — would ultimately yield and be demolished by such irresistible forces. Yet these low, insignificant coral islets stand and are victorious; for here another power, as antagonistic to the former, takes part in the contest. The organic forces separate the atoms of carbonate of lime one by one from the foaming breakers, and unite them into a symmetrical structure. Let the hurricane tear up its thousand huge fragments, yet what will this tell against the accumidated labour of myriads of architects at work night and day, month after month. Thus do we see the soft and gelatinous body of a polypus, through the agency of the vital laws, conquering the great mechanical power of the waves of an ocean, which neither the art of man, nor the inanimate works of nature, could successfully resist."* The corallines only work at a certain mean depth of a few fathoms beneath the ■waters. They generally commence on some sabmarine volcanic rock, on which they i , • Journal of Researches, S[e. By Charles Darwin, Esq., p. 547. GEOLOGY OF SCOTLAND, construct a line of reef until it reaches the surface. As generally happens^ the foundations, through the oscillatory movements of the crust subject to the volcanic action, subside and carry down the building again below the waves. Here the creatures renew their operations, which may be successively repeated. In this manner a great thickness of rock is often produced, and a lamellar structure, or divisional planes at the different off-sets, thereby communicated so as to give the appearance of stratification. The reef widens on both sides of the first wall, accord- ing to the nature of the bottom, by bringing up new tiers of mason- work. A considerable extent of surface is thus given to the reef, which, according as it is lagoon, encircling, or barrier, is increased by successive increments, as determined either by the instincts of the creatures themselves, or the conditions of the localities in which they carry on their operations. The origin and growth of the lagoon form of islands are thus described by the same author: — "It may be said, granting the theorv of subsidence, a mere circular disc of coral would be formed, and not a cup- shaped mass. In the first place, even in reefs closely fringing the land, the corals do not grow on the shore itself, but leave a shallow channel; secondly, the strong and vigorous species, which alone build a solid reef, are never found within the lagoon : they only flourish amidst the foam of the never-tiring breakers. Neverthe- less, the more delicate corals, though checked by several causes, such as strong tides and' deposits of sand, do constantly tend to fill up the lagoon ; but the process must become Slower and slower, as the water in the shallow expanse is rendered subject to accidental impurities. A curious instance of this happened at Keeling Island, where a heavy tropical storm of rain killed nearly all the fish. When the coral at last has filled up the lagoon to the height of lowest water at spring- tides, which is the extreme limit possible, how afterwards is the work to be completed ? There is no high land whence sedimevit can be poured down, and the dark-blue colour of the ocean bespeaks its purity. The wind, carrying calcareous dust from the outer coast, is the only agent which can finally convert the lagoon island into solid land; and how slow must this process be !" * Thus are islands formed, — thus is the massive framework of the globe, year by year, and age 'after age, increased and rendered solid. The great barrier which fronts the N.E. coast of Australia is probably both the grandest and most extraor- dinary reef now existing in any part of the world. It is described by Flinders as having a length of nearly one thousand miles, and as running parallel to the shore, at a distance of between twenty and thirty miles from it. The great arm of the sea thus included has an average depth of between ten and twenty fathoms, which increases towards one end to forty and even sixty; and all this vade interspace is probably now silting up with the calcareous mud and breakage of the reef, and in due time destined to become-one extended deposit of limestone. The Keeling or Cocos Islands, situated in the Indian Ocean, and about six hundred miles from the coast of Sumatra, are many hundred miles in extent, and entirely of coral formation. At the distance of little more than a mile from the shore, no bottom is found with a sounding line of 7,200 feet long ; and which, upon elevation, would therefore present the remarkable appearance of a lofty siibmarine-formed mountain, or high range of table-land, caped with limestone. The island of New Caledonia is nearly in length. 480 miles, with an average breadth of 60, and consists of coral, where a double line of reef projects 140 miles into the sea, while another line fronts the west coast of * Journal of Researches, p. 559. Is GEOLOGY OF SCOTLAND. about 400 miles long. Again, in the middle of the Indian Oceanj are situated the Laccadivej Maldive, and Chagos line of atolls, or lagoon islands, of which the Maldives constitute one single mountainous island, bordered by reefs, and very nearly of the same actual figure and dimensions with New Caledonia. And not to multiply instances, where they are innumerable, suffice it to state, that throughout the greater part of the East Indian Archipelago coral reefs abound along the shores of the mainland, as well as of the islands with which it is studded ; some with proofs of recent elevation, and others appearing as a grand circle of breakers, with, out a single spot of land or rock, though in due time certain to appear, through the ceaseless conflict of the storm-loving polypi. We feel surprised when travellers relate accounts of the vast extent of certain ancient ruins, but how utterly insignificant are the greatest of them when compared to the piles of stone accumulated in these seas by the work of minute animals, and every particle of which has been subjected to the power of organic arraugementi These little creatures are enabled to separate from the sea- water a proportion of lime, so minute as to be almost inappreciable, in the quantity present, by the most careful analysis. They secrete the stony coverings on the outside of their soft bodies. The figures of these incrustations are impressed and embalmed in the solid rock ; and some of them form themselves into compounds resembling trees, with root, stem, and branches, composed of separate and detached particles. A Layard wonders at the figures of men, war-horses, and strange animals recovered fresh from the chambers and walls of Nineveh and Khorsabad. Botta is fiUed with rapture as he paints them anew in his splendid work ; and Bonomi, or a Rawlin- son, has scarcely words by which to convey his admiration of their beauty and interest. It is thus, we may suppose, with the geologist, when he gazes on the ruins of an ancient world — on the broken escarpments and walls of limestone, imr pressed on every part with strange organic forms, and recalling to the imagination a period when Great Britain was emerging above the waters, encircled on aU sides with coral reefs, and surrounded with an ocean swarming with myriads of island- building corallines. The scale of erection here is one of boundless dimensions, encompassing in one and the same age the terraqueous globe, and, in point of antiquity, carrying him into epochs of time for which the historic calendar has no scale of measurement. What an elaborate combination of marvels in the structure of the lily-stone or encrinite, composed of thirty thousand articulating joints, inwoven every one of them with cartUage, and all as flexible in the moniliformis, and the other species, as the necklace jewel from which it derives its name, and piled on each other like the masonry of an elegant Gothic shaft. The pentacrinitey of which there are two living species, consists of 150,000 minute pieces of calcare- ous matter, articulated and lubricated in like manner, all moved at the will of the creature by a muscular system attached to every individual bone, rendering it, in the extreme organs or fingers, capable of contraction and expansion in every direction ; at one time spreading outwards like the petals of an open flower, and at another rolled inwards over the mouth like an unexpanded bud. The actinocrinus, or spiny encrinite, and the apricrinus, or pear-like encrinite, possess forms of no less singular beauty; the one invested all over the erect stem with a series of spines or flexible branches ; the other exhibiting in miniature the palmated crown of the palm-tree, and spreading its frond-shape tentacula with similar elegance of form. "When we consider," says Dr. Buckland, "the profusion of care, and exquisite contrivance, that pervade the frame of every individual in the genus of GEOLOGY OF SCOTLAND. Ixi pentacrinite, forming but one of many members of the almost extinct family of crinoideans — and when we add to this the amount of analogous mechanisms that characterise the other genera and species of this curious family — we are almost lost in astonishment at the microscopic attention that has been paid to the welfare of creatures holding so low a place among the inhabitants of the ancient deep ; and we feel a no less irresistible conviction of the universal presence and eternal agency of Creative care, in the lower regions of organic life, than is forced upon us by the contemplation of those highest combinations of animal mechanism which occur in that paragon of animal organisation, the corporeal frame of man/^* Nor was nature stinted in her production of these and other elegant forms of coralline life. Every one of those named consists of several species. The encrinite family prevailed over all, swarmed in every latitude, and fiUed every sea with the products of their labour. Their remains are found in every stratum of a calcareous character, and masses of limestone, from fifty to a hundred and fifty feet in thick- ness, are frequently seen to be entirely composed of them. Entire specimens, how- ever, are rarely to be met with, in consequence of the complex structure of the skeleton, and the perishable nature of the enveloping membrane, the separate pieces being disjointed, and having floated about after the surrounding cartilage was decomposed. They are sometimes mixed in other beds of limestone, and in shale, occasionally with shells, whose profusion in these cases determines the character of the beds. These shells, among the order Conchifera dimyaria, of the genera modiola, mytilus, and nucula are the most abundant; and in C. monomyaria, avicula, inoceramus, and pecten ; in that of Brachiopoda, lepteena, lingula, orthis, productus, spirifer, and terebratula; of Gasteropoda, buccinum, euomphalus, natica, nerita, and turbo; the bellerophon is the sole representative of the order Heteropoda ; and in that of the Cephalopoda, goniatites, nautilus, and orthoceras, are not only abundant, but are all remarkable for their size and elegance of form, the orthoceratites being frequently, in the quarries of Bo'ness and Closeburn, found of the gigantic dimensions of five to six feet in length by a foot in diameter. The fishes of the carboniferous age were also very abundant, consisting of several new types, and some of them of enormous bulk. Creatures allied to the family of sharks now for the first time appear, armed with teeth and jaws of fierce aspect, and covered with enamelled plates, through which a bullet could scarcely penetrate. Thus in the order of placoids no less than twenty-eight new genera, and a hundred species of the finny race, exist in the rocks of the period; of the ganoid order there are five genera, and twelve species; and of the saiu-oids, or, the approaching reptilian caste of organic structure, there are about thirteen genera, and twenty-four or twenty-five distinct specific forms. The estuary lime- stone of Burdie-House, near Edinburgh, is a perfect museum of organisms, of the richest and rarest kinds, vegetable and animal, from the smallest microscopic to the most gigantic of the marine tribes. Here are found the finest specimens of the Megalichthys liibberti, whose teeth are four to six inches in length, the scales, with which it was densely covered, of more than an inch in diameter, and all brightly enamelled, and a body supposed to have been at least fifty to sixty feet long. Here likewise are interred the remains of another equally huge and vora- cious animal, the Gyr acanthus, along with coprolites, or the foecal excrement of the genus, composed of the animal matter they fed on, and so numerous in * Bridgeicater Treatise, v. i. p. 442. Ixii GEOLOGY OF SCOTLAND. some spots as to form almost the entire mass of rook. The remains of the PaltEoniscus are very numerous, and in the most perfect state of preservatioBj every organism in its place, and the whole trout-like form of the body lying im- bedded in the grassy calcareous matrix, once the slime of the river that nourished them. The fronds of the ferns and other water-plants are spread out, in their most delicate fibres and tracery, on the thinnest divisional planes of the limestone; and so abundant often are they as to conceal every appearance of stone under their dense aborescent foliage. The plants are all of a terrestrial or fiuviafile kind, and so perfect and entire as to warrant the inference that they have not been tossed and drifted about in an ocean, nor transported from a distance, but have perished in situ, and dropped amid still waters. There are neither coals nor marine shells in. this deposit. Hence the presumption of its being a fresh- water, or estuary limestone. It may have been a lake, joined by a shallow neck to the borders of an ancient sea, whither the megalichthys, resembling the crocodile family in bulk, and the gyrocanthi, akin to the sharks in voracity, may have penetrated in quest of food, or indolently reposed by the umbrageous shades of its slimy margin. According to the relation now given, the physical features of Great Britain, as well as of the earth generally, would be very different from what they now are. The period in question was one not only of prodigious afiQuenee in vegetable pro- duce, but likewise of unprecedented exuberance in marine animal life, when all these northern latitudes were in the condition in which the coral districts of the Pacific are at present. Every coal-field was first the bed of a coral-reef sea. The islands and mainland were densely covered with groves of bananas and cacti, the fern, club-moss, and pine tribes, all of giant stature, and all encircling lakes and bays swarming with myriads of tropical creatures of corresponding activity and diversity of character. The whole of our seas, from Greenland southwards, through the central division of Scotland and England, the south-eastern parts of Wales, and large provinces in Ireland, over all the north-eastern districts of France, the Netherlands and Germany, were interlaced, separated into lagoons, and walled up by huge barrier-reefs. These reefs now constitute our mountain and encrinital limestones, the most valuable for building and all rural purposes. There, indeed, scarcely exists a doubt that the family of polypi, now rearing their wonderful structures in the Pacific, were the artificers in the olden times of all those masses of limestone which underlie and are intermixed in every coal-field, branching out and in among the metals, and an infallible sign that wherever we have the one mineral the other is not far distant. The animal and vegetable products of the age are entombed in the same basins, and are the sure indices, in their altered condition, of the presence of each other in the same geologic system. 3. The geographic distribution and economic history of coal. Like all the early formations of which we have been treating, the carboniferous sytem is one of universal diffusion. It prevails, subject to local irregularities, in every quarter of the glolje, under every clime ; and, unrestrained by mountains or seas, the coal metals constitute a treasure-fund available for all nations. The area of the coal measures in Scotland may be estimated at nearly one hundred miles in length, by an average breadth of thirty-three miles, extending east and Arest from St. Andrews to Ayr, and north and south from the Ochils to the Lammermuirs. This space is divided into a great many independent basins, determined in their size and direction by the older surrounding porphyries, and again broken up and subdivided by the eruption of the more recent greenstones GEOLOGY OF SCOTLAND. Ixiii^ and basalts. The coal metals, in their workable beds, are bounded by the old red sandstone of Stratheden in Fifeshire, never descending into the vale, and showing their general northern out-crop along the slopes of the Cults, Lomond, Cleish, and Saline hills. The eastern part of the Fife coal-field is one of the most disturbed and complicated districts in Britain; -where, in a space measuring about twelve square miles, of which Largo Law forms the centre, the trap covers nearly one-half of the surface, and penetrates the metals in every direction. The consequence of this intrusion of the trap is, that the faults and dislocations, and the variations of the stratified rocks in dip and position, are beyond calculation : the mountain limestone, instead of being found only at the margin of the basin, presents itself at intervals over the whole ; and the coal-field, instead of forming one extended basin, is separated into twenty or thirty detached portions, which are distributed over the district with the most capricious irregularity. Numerous slips, dykes, and bosses have elevated parts of the formation far above others, which, having been afterwards swept away by currents of water, have occasioned great diversity in the number of seams, even in contiguous localities, and rendered it often a matter of the greatest difficulty to recover the bearing of the once united strata. These remarks are applicable, more or less, to several other districts ; more especially to the remarkably disturbed out- line of country betwixt Kirkaldy and Lochgelly, the neighbourhood of Dun- fermline, Carnock, and Clackmannan; and, again, to the Stirling, Bannockburn, and Campsie coal-fields, where the undulating surface is everywhere diversified by dykes and outbursts of trap, occasioning innumerable ravines and divergent valleys^ and stamping the whole neighbourhood with the well-known physical features of the coal formation. The following statement will show the variable numbers and thickness of the seams in the different localities, arising chiefly from disturbing causes, and which have so much affected their original contiguity and more general uniformity in the mass. The coal metals, above the mountain limestone, commence on the north-east at Drumearro, bearing westward to Ceres, where seventeen beds occur, one of which is sixteen feet thick — not now wrought — and the average of the whole about seventy feet thick of the pure carbonaceous matter. The adjacent basins on the south-east are, Lathallan, Lathockar, Falfield, and Largoward, where there are eight beds, thirty-two feet tbick in all, one being thirteen feet. At Earlsferry, near Elie, beyond the trap of Largo Law, there are seventeen seams, as at Ceres, nearly sixty feet thick, and all dipping to the west ; while in the St. Monance and Pittenweem basin there are the same number of seams, but with an aggregate thickness of eighty-two and a half feet of coal. On the western side of Largo Bay the metals dip to the south-east, containing in the Wemyss and Kirkaldy coal-basin twenty- nine, in some places thirty-four, workable beds of coal, varying in thickness from two to twenty-one feet, and measuring in the whole 119^ feet thick. A smithy- coal occurs here, only eighteen inches thick, but of comparatively great value. A breadth of ten miles of sea, comprehending Largo Bay and a part of the Forth, divides these coal-fields from those of Earlsferry ; and as the inner beds of each terminate at the shore, and dip towards each other, and towards the water which divides them, the warrantable inference is, that other beds crop out under the Forth in the intervening space of ten miles. It has, therefore, been assumed that the real number of beds reaches to or exceeds forty. It is also very probable that they meet under the water, forming a trough, which is prolonged across the Frith, and re-appearing in the Musselburgh basin on the opposite side. The metals Ixiv GEOLOGY OF SCOTLAND. at Dysart, dipping tinder the sea, are wrouglit cine hundred feet below the surface.* Table, showing an approximation of the quantity of Coal that is wrought, and is still at warh, on the Wemyss and Dysart coal-fields— the richest and deepest coal-mines in Scotland, f 9 10 11 12 13 14 15 16 NAME OF SEAKI. Depth from surface at east end of West Wemyss. Wall Coal . Barncraig . . Coxtool Upper Ditto Under . Dea Coal . . Chemis . . . Bush . . . Parrot or Cannel Wood-coal . . Earls Parrot . Bowhouse . . , Brankstone Coal-more . . Coal-mangee . Dj'sart Main Coal Ditto Seven Foot Fathoms. n 15 4 9 12 10 30 5 14 13 5 11 11 36 10 Thickness of seams. Feet. Ins. 2 9 Number of imp. acres ■wrought, 1853. Number of tons raised up to July, 1853. 6 2 3 2 9 3 1 3 2 7 2 1 2 20 3 6 60 229 10 50 31 124,240 581,389 15,060 127,050 Number of imp. acres tu work. )52 1,870,176 53 106,000 60 140,362 29 85,833 86 291,368 9 25,416 104,904 300 732 300 600 400 500 636 100 s«i/29 600 1000 1500 1500 1500 4000 4000 Number of tons still to work. 621,200 1,860,012 451,800 1,524,600 564,750 1,694,000 1,242,000 233,936 85,833 1,524,600 3,388,000 2,961,107 2,223,000 2,859,000 20,328,000 10,164,000 These interesting calculations are made on the assumption of only 14 cwt. of saleable coal per cubic yard. Some of the data are simply approximations. In the thicker seams one half is allowed for pillars ; and in the thinner seams, which can always be wrought with less pillar, or long wall, from one third to one-fourth is allowed for waste and faults. The Barncraig is calculated at four and a half feet thick, coal being left for a roof; the Chemis at seven feet thick; and the Dysart main coal has been estimated one half at twelve feet, and the other half at six feet only, as the seam is thinner on the eastern, division of the estate, and a considerable portion is allowed for roof, pillars, and waste. A bed of limestone, varying from five to fourteen feet thick, intersects the district from Pittuchar, near Leslie, to Ravenscraig Castle, where it projects into the sea, resting upon bands of ironstone. This limestone occurs pretty high up in the series of the coal metals, having eleven beds of coal beneath, and generally only two or three above. Accordingly, to the west of this line, the average number of seams is not so great as on the eastern side, leaving us to infer that the upper portion of the coal-field has been here swept away amidst the convulsions and disturbances that have so much prevailed over the district ; and hence also it is, that in the western locality there is no trace of the upper red sandstone, which * Report on the East Coal-field of Fife, by D. Landale, Esq^. t Drawn up by Mr. Thomas Bywater, Wemyss Castle, and Mr. Jobn Kerr, Overseer of the Works. GEOLOGY OF SCOTLAND. IxT forms a marked feature in the petrology of the rocky shore from Kirkaldy to Largo Bay; Loehgelly, Gapledf ae, Halbeath,, Fordel^ Dunfermline^ and Carnock coal-vorks are all included within the denuded area, varying in their number of seams from four to fourteen, some of which are. from ten to sixteen feet thick, and having an aggregate thickness : of; thirty '■fiv© feet. Beautiful specimens of organic remains occur in some of the, basins;: spines,. scales, teeth, and other fragments of fishes — all brightly enamelled, and some of the teeth of enormous dimensions, fluted, striated, and as sharp and polished as in the living animal. The Wellwood and Dunfermline coal, .though of .no,; great thickness, are iCstremely flne in quality, pos- sessing; much of the soft texture and caking qualitiesof English coal. Two seams only are wrought; one four feet, and the other five and a half feet thick. Much of the sandstone here is of a bluish-black colour, arising probably from carbonaceous . matter; discharged from abed of anthracite which occurs to the westward, effected by the agency of trap dykes, or other kindred som-ces of heat. At Craigluscar, about •three miles north of the town,, there^occurs a remarkaMe intermixture of trap and limestone, in various alternations, and where the calcareous matter communicates to the ropk an extremely dark lustrous aspect. In the Elgin Colhery there are twenty- seven beds pf coal, some of which are extremely thin, the main seam being five feet two inches, and the total thickness of the deposit fifty-six feet. The Clack- mannan coal-field extends from the Forth to the Ochils, bounded on the east by the Cleish and Saline hills, and the beds in several places are much interrupted by slips or faults. There is one fault, which occurs a little to the south of the Devon, that occasions a shift in the strata from 700 to 1230 feet; and in Law Hill, near Dollar, a greenstone trap has completely charred all the coal in the vicinity. Some of the beds abut against the Ochils, where they are almost vertical, rubbed, and crushed, and present aE the phenomena of the most violent mechanical action through the upheaval of the trap. . The coals generally, however, are of excellent quality, consisting of twenty-four seams, which vary from two inches to nine feet thick, and average about sixty feet in all. Fire-clay, clay-ironstone, and black- band are very abundant in the district. The cannel or parrot variety of coal occurs in most of the .basins now enumerated. The coal.' field of the Lothians is engirdled along its east, south, and west out- crop by a belt of old red sandstone, which is succeeded by the grauwake and sUurian rpcks; of the Lammermufrs. The metals generally dip from these older formations towards the sea, any deviations in the interior of the basin being produced by the eruption of the igneous rocks. The coal measures extend from Aberlady Bay to near Linton, in which there are no less than fifty-two slips, whereby the strata are depressed 5169 f^et towards the north; while again, in the same direction, they are raised ,by. thirty-seven slips, or steps of elevation, 241.3 feet, the difference being 3'?67:feety or nearly the maximum height of the hills on the south.* The strata are not much inclined or shifted from their original horizontality, which shows the change of level to have been produced by a simultaneous subsidence over the whole area of the .field, occasioned perhaps by the ejection of the matter of the igneous roeks^ and which in dykes, ridges, and^ hills forms no inconsiderable mass. North Berwick Law, Traprain Law, the Bass Bock, Arthur's Seat, the Braid and Corstor- phiae hills, all lie on the verge, or rise within the limits of the coal-field. There are about sixty seams, of workable, coal in the more central division of the basin, one of which is thirteen feet thick, the rest generally under ten, and aU of them thin * Beport of Mid-Lothian, hj Bi Milne, ^sq. k Ixvi GEOLOGY OP SCOTLAOT) out towards the south and west out-crop of the metals. The aggregate thickness is estimated at 126 feet, attaining its maximum towards Niddry, Dalkeith, Gilmerton, Tranent, Musselburgh, Prestongrange, Elphinstone, and Cowdens. The encrinite, or mountain limestone, underlies the whole series of coal seams now described, encircling Edinburgh on the north, and extending westwards by Cramond, Aber- corn, and Blackness, to Falkirk. The coal along this line, never of any great extent, is nearly worked out: the beds chiefly belong to the under series, accom- panied with an enormous mass of sandstone, shale, and other strata, about two thousand feet thick, and which has been everywhere invaded or overlaid by the trap. A low range of trap hills, extending from Bathgate to Linlithgow, divides the Falkirk and Stirling coal basins from those now described on the east, and from the extensive mines of Lanark on the south-west. The Bathgate coal basin pos- sesses points of great interest to the mineralogist. The encrinite limestone which is wrought at Bowden Hill under the trap is about sixty feet thick, extending N.N.E. to Linlithgow. A fresh-water bed occurs in the adjoining parishes of East and Mid Calder; and at Kirkton there are ferruginous or bituminous beds of shale mised with translucent silex, laminse of pure limestone, porcelain jasper, and the remains of Europterus Scouleri. A rich black-band ironstone is wrought at Polkemmet, and a still more remarkably rich bituminous shale,* termed by the workmen a cannel coal, * WLile these pages are passing through the press the question is raised, in the Court of Session, as to the mineral qualities of this bed, which has an average thickness of eighteen inches, and yields a more than ordinary proportion of inflammable gases. The pursuers in the action ai'e Mrs. Elizabeth Houeyman and her husband, William Gillespie, Esq., of Torbane Hill ; and the defenders are Messrs. James Eussel and Son, coalmasters at Blackbraes. The witnesses on both sides consist of the most eminent geologists, chemists, microscopists, scientific and practical mining engineers in Great Britain ; and, having taken part in the trial, we have had access to the con- versation,^ opinions, and reasonings of both parties, debating the question whether it is to be classed with the coals or shales, -with the greatest ability, and manifesting the most intense interest in the merits and results of the trial. Professor Ansted, as first witness, said, that viewing the mineral geognostically in the field, " he considered it as technically allied to the underclays of the coal measures ; and as a commercial definition of the substance, he would designate it either as an indurated mineral pitch or asphalt, combined very closely with clay impurities, or as a clay largely impregnated with mineral bitumen." Professor Fleming decided, upon a careful examination of the mineral, that "it was nothing else than a good cannel coal, containing in abundance the various coal plants, visible to the naked eye, usually found in the coal measures." Mr. Hugh Miller, the author of the Old Bed Sandstone, said " he found the Torbane mineral to difi^er from all coals he was acquainted with, in the circumstance that it had not a fixed carbonaceous base, and had, what all true coals wantedj a base of earth, which remained in the same bulk and form after the consumable parts were burnt out, as shales did." Among the chemists. Dr. George Wilson said, that " he considered the mineral to be a clay, largely impregnated with bituminous matter, and that, after repeated careful analysis, the results were: of carbon in coke, 4-13; volatile matter, 68-12; ashes siKcate of alumina, 27-75 ; mean specific gravity, 1-247 ; and that, after the volatile matter has been expeUed, there remains in the retort a black mass, which, when heated in the open air, is found to consist of 87-05 per cent, of earthy ingredients, principally silicate of alumina (clay), the remainder being carbon." Professor, A. Pife "had analysed all the cannel coals in Scotiand, with a view to their gas-producing qualities, and considered the Torbane mineral to differ in no respect from the ordinary cannel coals, except its being of a very superior quality." Comparing its constituenta ■ wjth the Capeldrae cannel coal, he found them to be as follows :— TORBANE HILL MINERAL. Carbon 60-25 Hydrogen g.g Oxygen 3.5 Nitrogen I.5 Sulphur Q.g ■A-sh ■. ■ 25-6 CAPELDRAE. Carbon 56-7 Hydrogen 6-8 Oxygen 8-8 Nitrogen 1-9 Sulphur 0-25 Ash 25-4 .J. S. Bowerbank, Esq., author of A History of the Fossil Fruits and Seeds of the London Ola GEOLOGY OF SCOTLAND. Ixvii is extracted in great masses jfrom the pits of Boghead^ Bathyale, and Torbane Hill. There are four seams of coal, varying from six inches to three feet thick, intermixed ■yrith fire-clay and nodnlar ironstone. SigiEaria, stigmaria, lepidodendra, and other coal plants, are extremely abundant in all the beds. Near Carron, in the Falkirk basin/ the coal consists of seven or eight beds, generally thin, and of an aggregate thickness of twenty to twenty-five feet. The metals are worked at a great depth, nearly six hundred feet, -where they dip under the Carse clay, and vast accumulations of sand and gravel, -which here form interesting objects of attraction to the antiquary, as -well as the geologist. Similar alluvial formations cover the coal-field around Lecropt, Denny, Bannockburn, and Kilsyth: the seams generally rise to-wards the Campsie hills, extending along their sides, and are often overlaid or completely insulated by the trap, which in some places has so charred the coal as to convert it into anthracite, or coke. A manufactory of alum, copperas, and Prussian-blue has been established at Campsie. The material is derived from a bed of alum-slate, which lies above the coal. When the coal is removed the air decomposes the slate, causing it to eflloresce and to resolve into a soft, unctuous mould of earth. The line of railway betwixt Edin- burgh and Glasgow runs along great part of this coal-field, cutting the strata at right angles often; in other places ,the section is parallel to the beds; and the and other works on Fossil Botany, " had carefully examined thin sections of the mineral substance hy microscopic powers, varying from 160 to 660 linear, by both transmitted and direct light ; that it had no vegetable structure, and, therefore, he was of opinion that the substance cannot with truth be designated coal ; but that, as a substance, it should be classed with the resinous and argillaceous shales, consisting of resinous and earthy matter, and not, like coal, of organised carbonaceous matter and bitumen." Professor Balfour described the structure of the mineral, as exhibited by the microscope, " as a vegetable structure, of which there were three kinds in coal, — the woody fibre, the scalariform, and the cellular tissue, — all of which were found in the Torbane Hill mineral. Shales did not exhibit any traces of vegetable structure." J. Quekett, Esq., Professor of Histology in the Royal College of Surgeons, London, " has examined by the microscope most of the known coals in England and "Wales, — about seventy varieties, — in all which the tissue is woody; discovered no organised structure in the substance of the Torbane mineral, while, . in its general structure, it was different from anything he ever saw in his life before. The basis of the mineral is a porous slate, the pores or interstices of which have been filled with an inflam- mable material somewhat resembling bitumen, but yet differing from this substance in many particulars." Several other eminent scientifie witnesses, on both sides, bore corresponding testimony to the above. The counsel, all of the highest standing at the Scottish bar, next addressed themselves to the jury, bringing, in illustration of their conflicting views, all the wit, humour, logic, eloquence, and law of the profession. The court, through the presiding judge, then went over the various points of the evidence, declaring its inability fully to appreciate its scientific import, and yet valiantly describing the scientific distinctions as " crotchets." A respectable and intelligent jury, after six days' trial, found a verdict in behalf of the defenders, resting chiefly on the terms of the, lease, but also virtually implying that the mineral in question was coal. Another jury, presided over by other judges, will have the matter in dispute before them anew ; when, stripped of all its legal and commercial adjuncts, the Torbane Hill mineral will receive its fixed and true place, whatever that may be, as one of the richest and most valuable inflammable substances yet discovered in the bowels of the earth. The undisputed and permanent mineralogioal characters of this interesting substance are — specific gravity, about 1-16Y; structure, amorphous; colour, dark brown ; streak, brown, earthy- looking ; fracture, semi-conchoidal ; translucent on the edges, very inflammable, argillaceous or bituminous odour ; white soft ash, and yields no coke. In all true coals there is a preponder- ance of fixed carbon over ash — varying in degree, but constant, and forming coke. In the dis- puted mineral the reverse is the case. In Professor Fife's analysis the carbon is not fixed, but is a product, as in oils. Our first impressions, therefore, are only the more confirmed by the conflict of opinion elicited in this legal discussion — that the mineral in question must be classed with the shales, and is not a coal. IxviiL- -^ GEOLOGY OF SCOTLAND. intrusive rocks are shown in tlie most interesting mannerj in.L every variely > of position, form, and disEw^^nce. ' ' " f'" i The Lanark eoal-field is'kifflided on the sontli and -west. hy- the Eentlands md Renfrew trap hills, and embraces a-yast extent of country, diversified: by the wind- ings of the.Clyde, and where some of'tiie richest minerals; are Jying: in the water- shed of the river. Within the area of this fieRthere ::are a greats many mines— an inexhaustible repertory of coal and ironstone. The jeity of Glasgow is built over the metals; and, being of comparatively easy access in the vicinity, they form the chief source at once of its stirring activity and aceumulatiug wealtli.> The many ravines and elevations in theidifferent parts of the city, the undulating contour: of .country north and south, the outbursts of trap at the Necropolis: and other localities, ;and the various dykes of the same igneous formation that: shoot everywhere around, are aU clear indications of the mineral treasures beneath, and of :the elevatory forces that have arranged, them- into convenient sections for the miner. Immediately to the west of Glasgow, on the north side of the Clyde, the coal is not abundant; the deposit seems to belong principally to the lower part of the series, or mountain limestone ; nor are the relations : of the strata there very well ascertained. Fossil trees frequently occur in the^ sandstone : a fragmenti tteee feet long, and twenty-six inches in diameter, : with four long roots inserted in the rock,: was at onetime exposed in a quarry north of Sauchiehall-street ; and four others, situated in. a line at nearly equal distances, were to be- seen in a quarry north from the. Eelvin aqueduct.* The Hurlet and Quarrelton coal-field is five miles south-west from- the city, on the opposite side of the river, where the coal, though considerably deteriorated by masses of iron pyrites, is of great thickness at Quarrelton, varying from fifty to sixty feet ; and in one place ten beds, ninety to j a hundred feet thick, are found together,'-'perhaps the thickest mass of bituminous matter ever discovered. A blidsli amygdaloidal greenstone, a hundred feet thick, has penetrated the basin, and oVerlies great part of the minerals; and, in consequence, local authorities have inferred, as an explanation of the phenomenon, that the beds of coal were first raisediby a vertical, and then pushed over each other by a horizontal motion. A thin bed of alum-slate occurs at Hurlet, manufactured into alum and copperas, as at Campsie ; and as the strata, on both sides, dip towards the Clyde, thus causing it to follow the bottom of a trough or basin, there can be little doubt that the alum-slate is an extension of' the bed which occurs at Campsie. At Maxwelton, Blackball, Nitshill, and Hallhill, which surround Paisley, and form the southern boundary of the Clyde basin, the beds of coal vary from six to sixty-six in number, from a few inches, io ten feet in thickness, and in the aggregate from twelve to twenty feet of good, workable -metals. The mines on the east and south-east are wrought in the parishes of New Monkland, Airdrie, Shotts, Eathgate, Bothwell, Hamilton, Carluke, and Carstairs, where,an general, there are eight or nine workable seams, in some places upwards of thirty, with a total thickness of from twenty-five to thirtyrSeven feetif The whole field abounds in black-band ironstone, varying from a foot to a foot and a half, and in several places a clay-ironstone, or ochreous shale, yields the ore in considerable supply. The Airdrie and Gartsherrie black-band yields from 34 to -39 per cent. ;of iron, land contains so much carbonaceous.matter as nearly to com- * Nicol's Guide to the Geology of Scotland. t iCraig's Ilssay on the Carboniferous Formation of Lanarhshire. GEOLOGY OP SCOTLAND. Ixix pletetteprocess of caielnatioB/witlv only a; small expenditure of coal. The quantity of i GOals -brouglit to' GflasgpT^; ' in 1836> from thirty-«even pits in the vicinity, amwmted to 561j049 tons, of which 124,000 were exported ^to the Highlands and adjaeetit pi&ees on'the Clydej thusi leavihg for the use of families and public works in the -eity and suburbs, 437^049 tons of coal. -The population since that period has nearly doubled, and the public works have increased perhaps in a still higher;ratio.> Hence the present consumptioa will amount to about 874,098 tons. But, as exhibited by^ the books of the Eiver Trust, there were exported, for the year ending the 3©th Junej 1852, from Grlasgow, 200^560 tons of coal,, which, added to the ■^uEoitity- consumed in the city and subu3*bs, shows- that : the coal-fields surrounding the western metropolis of Scotland yield an annual; product of. one Mllion"ge/eeMy-f our thousand jipe hundred and fifty-eight to'os, of coal, over and above all that is constimed at^ thepits, the blast furnaces, and the numerous towns and populous vUlages embraced within their area, or situated on their confines; i - The coast from Port Glasgow to-Ardrossan consists, for the most, part, of the old i red sandstone,: .which- in several places is of great thickness, generally fine- grained, though occasionally conglomerate, and usually of a deep brown-red. The interior, as > well as the north-west of Renfrewshire, is much covered with trap rocksy of the ifelspar-^porphyry formation, and underlying the coal on both sides, separates the Clydesdale from the Ayrshire coal basin. The district is very rich in this Useful mineral, The amount of coal shipped at the two ports of Irvine and Troon, during the currency of the year 1852, was little short of three hundred thousand foM*— that- of Troon alone being 245,300 tons. Near Ayr, one bed at Taiglum is eleven feet thick ; the Irvine beds are five in' number, three of which being three feet each, and two seven, making in all twenty- three feet of excellenl workable, coal ; while- in the north-west, in the vicinity of Ardrossan and Dairy, there are nineteen feet of coal in six bedsj from two to four and a half feet thick. The shipments at Ardrossta, for the .same period, amount to 63,744 tons. Anthracite occurs, in a bed of four to five feet thick, at Eiccarton, south of Kilmarnock, resting on sandstone. ^The whole field abounds in ironstone, in beds varying from sis inches to nearly two feet thick, yielding a very high per centage of iron, and is surrounded by thick masses of the encrinite or mountain limestone, which crops out and is extensively worked at various places along the edges of the basin. The remainder of the veestern coal measures is broken up into small detached ■ basins,' generally separated by igneous rocks, but frequently containing numerous seams of great aggregate thickness. The basin of Dalmellington occupies the vaUey of the Doon, ^consisting of seven beds of coal, of which one is nine feet thick. Another small isolated basin occurs in the old red sandstone, by which it is com- pletely environed, near Dailly and north of Girvan, where the coal seams have an average thickness of forty feet. The Cumnock and Muirkirk basins lie to the north-east, surrounded on all sides by trap hills, of which Corsancone forms the apexy raising the western portion of the metals at New Cumnock about a thousand feet above the sea. Around Mansfield there are six beds, about forty feet thick, three of them being respectively nine, eleven^ and twelve feet; this basin is ten miles long by five broad, and at 4he highest point the coal metals lie on the surface, with very little dip or inclination towards the interior. On the north-eastern side, between Mauchline and Muirkirk, there are eight beds, one nearly ten feet, and the whole about forty-four feet thick. Lower down ia the valley of the Nith, the Kirk^ Ixx GEOLOGY OF SCOTLAND. connel and Sanquhar coal-field stretches in a south-easterly direction, having a length of seven by a mean breadth of two miles, and containing twelve seams of coal, three of which average four feet thick j it is intersected by numerous faults and greenstone dykes, which have greatly crushed and charred the metals, and in one place changed them into columnar anthracite. The coal measures stretch from near the town of Annan, along the shores of the Solway, to Cannobie, where the coal is wrought at Byrebum on the Esk, below Langholm, but now nearly exhausted. A greater thickness of the valuable mineral occurs on the Eowanburn, a tributary of the Liddel, about a mile to the south-east, where there are three or four seams vrrought with profit. But although extended along the entire water-shed of this border river, and beyond Carter Fell towards the Cheviots, no workable beds occur east- ward of Lawston, where the strata are thrown up by the trap with a westerly dip, and which all belong to the under series of the carboniferous system. The encrinite limestone crops out in various localities around the coal-field, of great thickness and purity, skirting the northern side of the basin from Ecclefechan to Langholm, and, running in long ledges or broken up into large tabular masses, forms a very picturesque scene in the trough of the Esk, near the water-mill adjacent to Armstrong's Tower, of border renown. A narrow belt of the old red sandstone, of the upper or yellow series, succeeds the limestone a little to the north, resting upon the grauwake. An iuteresting junction of the three formations — sand- stone, trap, and grauwake — may be observed in the gorge of the Esk, about a mile below Langholm, near the bridge, where the trap has considerably altered and uplifted the sedimentary rocks; while, to the north-east, the sandstone has been elevated more than a thousand feet, capping the summit of Whitock HiE, and fur- nishing material for the beautiful monument there erected in honour of Sir John Maclom, of Indian celebrity. The general results to be deduced fi'om this description of the several coal basins of Scotland are as follows — results highly important in a geological, but stiU more in an economic point of view: — Taking, as already stated, the length of the great central basin at 100 mUes, and its breadth at 33 miles, and deduct- ing for the area of the Firth of Forth under water 360 miles, there remain about 2874 square miles of the coal measures, or of the strata classed in the coal formation. JBut deducting the portion which underlies the mountain limestone, extending from St. Andrews to Drumcarro, and from Pittenweem to Crail, and making allowance for the intrusive rocks which prevail largely in every district, probably not more than one-half of the superficial area of the coal measures, or 1436 square miles, can be regarded as available for working coal. The average number of good coal seams is twelve, and their total average thickness about thirty-four feet, and making allowance for faults and dykes, there are nearly, at a rough estimate, fourteen million cubic yards of coal in each square mile. The average weight of a yard, or of three cubic feet, is one ton ; in the 1436 square miles there wiU be about eighteen billions of tons ; and, therefore, according to the estimated thickness of the whole coal basins at thirty-four cubic feet, the amount of the valuable mineral inclosed in the several coal basins of Scotland cannot be regarded as less than one hundred and eight trillions of tons — a quantity sufiicient, even at the present high rate of annual consumption of about six millions of tons, to supply the increasing wants of the country for two thousand yeai-s. The clay ironstone and black-band may be regarded as nearly co-extensive with the coal measures. There are few coal basins, at least, in which one or other of these GEOLOGY OF SCOTLAND. Ixxi fonns of the iron, ore have not been discovered and wrought. The number of hot- blast furnaces in operation in Scotland during the years 1853 and 1853 are, accord- ing to the returns now before me, 102, of which the Gartsherrie works have the greatest number. The average produce of pig-iron, of each furnace, is about sixteen tons a-day; thus yielding a total annually of 509,184 tons weight of pig-iron, or of metal in a state for commercial purposes. This vast product, raised from the coal- fields of Scotland, has been chiefly owing to the successful researches made for the black-band ironstone within these twenty years, and the improved methods of smelting the ore by means of the hot-blast furnace. The present market-price of pig-iron is from £2^ 16s. to £3 ; hence the total annual value wiU be about one million and a half pounds sterbng. The value of the coal at the rate of 6*. a ton wiU be considerably above this amount, or about £1,700,000 a-year. The lime cannot be estimated at much less. Thu^, in aU, the commercial produce of coal, iron, and lime raised from the coal measures of Scotland will be little short, in annual value, of five millions of sterling money. The whole mineral produce of the kingdom in 1814 was only about £1,600,000, and of which amount the three substances mentioned constituted the proportion of £1,440,000. While the coal metals, with their constant associates, lime and ironstone, are now ascertained to exist in every continent and in all the larger islands, the boundaries of many of the coal-fields have been measured, and a comparative estimate of their minerals determined. In proportion to their extent the richest mines in the world are those of Great Britain, which occupy a space of nearly 8,000 square miles of workable coal. The American coal measures, in the States alone, cover an area of about 133,000 square miles ; a single coal seam, of an average thickness of ten feet, occurs in Pennsylvania, which spreads uninterruptedly over an extent of 14,000 square miles; while the coal-basin of Illinois, Indiana, and Kentucky, is not much inferior in superficial dimensions to the whole of England, A computation of the quantity of vegetable matter, in a given portion of eoal, has been made, and the result is, that a cubic yard of coal weighs upon an average one ton — a bed of coal of one acre in extent and three feet thick contains 4,840 tons — and the produce of 1,940 acres of forest trees is absorbed in one acre of coal. Multiply the 8,000 square miles of the coal-fields of Great Britain, or the 133,000 square miles of the coal-fields of the States, by the denominator given, and the number of tons in a single bed of three feet thick is prodigious, showing ho>r inexhaustible are the stores of the useful combustible for generations to come. But instead of one bed, the coal-basins range from ten to nearly a hundred seams of the mineral, and instead of three feet thick, many of the seams are from ten to twenty feet in thickness ; and thus, taking the compu- tation all the world over, no intelligible array of figures can represent, as no human mind can grasp the conception of, the infinitesimal results in weights and measures of the all-bountiful gift stored up for man's use and improvement in the stony chambers of his habitation. The author has elsewhere * related, on this subject, " that it does not appear, from any well authenticated records, at what precise period man availed himself of this useful mineral, either for the purposes of art, or of domestic comfort. The early history of nations is traditionary ; but there is no tradition from very remote times, in any of them, as to the discovery of coal — no philosopher speculating about * The Course of Creation, p. 120. Ixxii GEOLOGY OP SCOTLAND. tlie importance of the fact, and its bearings on the prdgress of civilisation/ ;;;.'. . What the Romans termed lapis ampelites, is generally uiaderstbod to mean biir cannel coal, which they used not as fuel, but' ia making toys, braceleits, tod other ornaraents ; while their carbo, which Phny describes as ' veheinenter peflucet,' was simply the petroleum or naptha, which issues so abundantly from all the tertia^ deposits. Goal is found in Syria, and the term frequently occurs in the sEtefed writiiigs. But there is no reference anywhere ia the inspired record as to' digging or boring for the mineral, and no directions for its use. • In their burnt-offerings^ wood appears uniformly to have been employed. In Leviticus the term: is used as synonymous with fire, where it is said that 'the priests shall lay the parts ia order upon the wood, that is, on the file which is upon the altax.' And in the skme manner for all domestic purposes, wood and charcoal were invariably' made use of. Doubtless the ancient Hebrews would be acquainted ' with natural coal, as in the mountains of Lebanon, whither they continualy resorted for their tunbetj' seams of coal near Beirout were seen to protrude through the superincumbent strata iii various directions. Still there are no traces of pits, or excavations into the rock, to show that they duly appreciated the extent and uses of the article.- Their terin ^m, which properly signifies charcoal, appears to have passed into the northern languages, as in the Isiandic ^foa ; the Danish ^foe; the Welsh ^fo, a coal=---^ofeM^ to give hght; the Irish o-gual ; and the Gornish Aofew; terms £dl expressive of the act of burning, or of giving light. " For many reasons it would seem that, among modern nations, the primitive Britons were the first to avail theniselves of the valuable combustible. The word by which it is designated is not of Saxon but of British extraction, and is still employed to this day by the Irish in their form of o-gual, and in that of kolan by the Gormsh. In Yorkshire stone hammers and hatchets have been found in old mines, showing that the early Britons worked coals before the invasion of the Eomans. Manchester, which has risen on the very ashes of the mineral, and grown to all its wealth and greatness under the influence of its heat and light, next claims the merit of the discovery. Portions of coal have been found under or imbedded in the sand of a Roman way, excavated some years ago for the construction of a house, and which, at the time, were ingeniously conjectured by local antiquaries to have been collected for the use of the garrison stationed on the route of these warlike invaders of Mancenion, or the Place of Tents. Certain it is, that fragments of coal are being constantly, in the district, washed out and brought down by the Medlock and other streams, which break from the mountains through the coal strata. The attention of the inhabitants would, in this way, be more early and readily attracted by the glistening substance. "Nevertheless, for long after, coal was but little valued or appreciated, ttirf and wood being the common articles of consumption throughout the country. About the middle of the ninth century a grant of land was made by the Abbey of Peter- borough, under the restriction of certain payments in kind to the monastery, among which are specified sixty carts of wood, and, as showing their comparative worth, only twelve carts of pit-coal. Toward the end of the thirteenth century, Newcastle is said to have traded in the article; and by a charter of Henry III., of date 1284, a license is granted to the burgesses to dig for the mineral. About this period, coals for the first time began to be imported into London, but were made use of only by smiths, brewers, dyers, and other artizans, when, in consequence of the smoke being regarded as very injurious to the pubHc health, ParHament petitioned GEOLOGY OF SCOTLAND. Ixxiii the King, Edwaxd I., to prohibit the buming of coal, on the ground of being an intolerable nuisance.' A proclamation "vras granted, conformable to the prayer of the petition, and the most severe inquisitorial measures were adopted to restiict oi altogether abolish the Use Of the combustible by fine, imprisonment, and destruction of the filmaces and wOrlcshops ! They were again brought into common use in the time of Charles I., and have continued to increase steadily with the extension of the arts and manufactures, and the advancing tide of population, until now, in the inetrbpolls and suburbs, coals are annually consumed to the amount of about three mUhOns of tons. The use of coal in Scotland seems to be connected with the rise of the monasteries,; institutions which were admirably suited to the times — the con- servators of learning, and the pioneers of ^ art and industry all over Europe — and in whose niost rigorous exactions evidences can always be traced of a judicious and erJightened concern for the general improvement of the country. Under the regime of monastic rule at Dunfermline, coals were Worked in the year 1291, — at Dysart, and other places along' the coast, about half a century later; and, generally, ia the fourteenth aiid fifteenth centuries the inhabitants were assessed in coals to the churches and chapels, which, after the Reformation, have stiU continued to be paid in many parishes. Boethius records that, ra his time, the inhabitants of Fife and the Lothians dug ' a black stone,' which, when kiadled, gave out a heat sufficient tomelt non." Thus tardily have all our most obvious discoveries been made, and their uses a,pplied. The pits from which the black stone was dug are stiU to be seen near CraH, and Other places along the coast of Fifeshire, penetrating the surface only a few feet, and merely the out^crop of the metals touched. The ground itself had first to.be cleared of its massive forests, sufBcient for ages to supply the wants of the inhabitants, while aft was young and the inventive sciences little understood. The social laovehient now in progress is mainly the result of both being carried to a pitch of which our forefathers never dreamed. The pressure in the moral may be compared to the expansive forces in the physical world,— all latent a few years ago, but now in such vigorous activity, in the various appliances of steam, mechanism, , and electiricity, as to change the whole aspect of society, and to convert the wilder- ness into a garden. They are mutually assistant to each other: the march of civilisation advances apace, and the resources of the mine are more and more available; the treasures of the earth, hidden and unknown for ages, are fiiUy appreciated, and their practical' beiiefits ascertained. The arrangements of a far- seeing Providence are clearly discernible in the mighty operations and vast inteL lectual achievements already realised ; the relics of distant ages have become, not the toys of the antiquary, \>ui the giant levers of the man of science; and, as there are no limits to the resources, so will the genius of coming generations be stimulated to new exertions, and rewarded with new means of comfort and improvement. . The doctrine of final causes here receives one of its most striking verifications. No truth in. history is better established than that the whole earth has been given to man as the theatre on which is to be fulfilled the revealed destiny of his race, — when civilisation shall be co-extensive with its boundaries, when the arts and sciences shall be as widely cultivated, and when pure and undefiled religion shall prevail in all its borders. The old branches of the human family are in rapid decay : the pioneers of a higher moral and intellectual development are everywhere planting themselves in their desolate places. The mineral stores under- ground furnish the principal means of their conquest, occupancy, growth, and IxxiT GEOLOGY OF SCOTLAND. permanent establishment in their new fields of location. Not an island or continent on the terraqueous globe, and within its habitable domains, that is not of the easiest access to civilised man. The fuel and the metals that enable him to speed his way and consolidate his power, he digs from the bowels of the earth. Garnered up in ages long past, and, as designed on purpose to meet the requirements of his lot, he finds them in every region where his enterprising spirit leads, whether he is to promote the cause of truth while yielding to his own propensities, or to accelerate the spread of knowledge by the ingenuity which prompts him to extend his own dominion. When the gold and the silver mine is exhausted, and the feverish excitement that drove him to his new settlements is past, the more peaceful occupations of life will be pursued, the cultivation of the soil become his enjoy- ment, towns and cities arise on every side, and amidst all the busy appliances of commerce and the arts, the school and the church will appear. The grandest achievement of his moral destiny will be thus accomplished — the ends of the earth brought together — the promise again realised — " I will bring thee to a land whose stones are iron, and out of whose hills thou mayest dig brass : when thou shalt lay up gold as dust, and the gold of Ophir as the stones of the brooks." THE NEW RED SANDSTONE AND SUPERINCUMBENT STRATA. The series of rocks which immediately overlie the coal measures is termed the New Red Sandstone, in contradistinction to the Old Red, which is subjacent to the coal, and belongs to an anterior geologic age. The irregular expanse of sea left in the regions of Britain by the broken masses of land, produced by the uplifted carboniferous rocks, was filled by the detritus of the period, and afterwards consoli- dated into a succession of sandstones, clays, marls, and limestones. This formation occurs in Ireland, but not abundantly, and only in the north-eastern part, which may be regarded as an extension of the Lammermuirs. In Arran, and on the west coast of Ayrshire, on the southern slope of the Lammermuirs, around Dumfries and Langton, is a large tract of these rocks, spreading into the plain of Carlisle, the vale of Eden, and against the west face of the Cambrian mountain limestone. The new red sandstone and the superincumbent strata occupy nearly the whole superficies of the central, eastern, and southern districts of England. It is largely developed in America, on the continent of Europe, and especially in Russia, whence, from the vast extent occurring in the district of Perm, it has been denominated the Permian System, and is generally described as such in works on geology. The formation is found in Scotland only in patches, at remote intervals, round its borders ; and, in some of the localities, the position of the sandstones is by no means a settled point, whether as belonging to the coal measures, to the old, or to the new red series. There are great diversities in the number, mineral qualities, component ele- ments, and external appearance of the strata belonging to the new red sandstone. Indeed, so very different are they, that nothing but their relative position, and the substances with which they are associated, can determine the true systematic character of some of the beds. In Germany, Erance, and England, there is often the widest distinction, which has given rise to different systematic arrangements, as well as to a different nomenclature, dependent only on some prevailing local pecu- liarity ; and teaching the important fact, that it is by general types, and not by any conventional series of strata, that rocks are to be identified in different countries. GEOLOGY OP SCOTLAND. Ixxy A deep red variegated sandstone, magnesian limestone, gypseous marls, sometimes beds of crystallised gypsum, and occasionally rock-salt, may be considered as the cbaracteristic mineral substances composing the system. The whole series of beds, too, are generally fine-grained, thinly laminated, and easily split up into slaty fiags, and the different strata are usually separated by soft unctuous clays, or calcareous marls. As the period appears to have been comparatively barren both in animal and vegetable life, so the mineral wealth of the system cannot be highly estimated, forming a remarkable contrast in this respect with the coal measures. The mag- nesian — or, as it is likewise called, the dolomitic limestone — yields, under chemical treatment, the magnesia of the apothecary ; and, although the soils connected with this rock are neither rich nor genial in their appetency for the cereals, yet a certain admixture, when reduced to quicklime, is not unfavourable to some of the grasses. It furnishes in some localities a beautiful and durable building-stone, of which, from the quarries in Bolsover Moor, in Derbyshire, the new Houses of Parliament are ■ constructed. The flaggy schists are employed extensively for lithographic purposes, the admired German blocks being chiefly derived from these beds. The gypsum and rock-salt of commerce are likewise dug from this formation, sometimes alternating with the other strata, in thin stratified beds, or occurring in basins, in irregular masses, from twenty to a hundred and twenty feet in thickness. The Chester, Worcester, and other salt- pits in England, — also those in Spain, Germany, and Austria, — the celebrated mines of Cracow, in Poland, — " Where, scoop'd in the hriny rock, long' streets extend," — and the recently discovered beds in Ireland, — are all situated in the new red sand- stone ; and all as yet form the subject of controversy, whether these saline crystal- lisations owe their origin to deposition in water, or to the vaporising influence of heat. With the exception of an ore of copper, wrought to some extent in Germany, termed kupfer-schiefer, no other metal is derived from the system. When compared with the carboniferous system, so rich in organic remains and in mineral treasures, the new red sandstone indicates one of those vast changes in the course of nature which demonstrates a direct interposition of creative power. The superabundant flora of the past age becomes suddenly extinct. The materials of three to four thousand feet of solid rock are collected, without a particle of coal being contained in the mass. The myriads of creatures which filled the seas, and whose remains form the mountain limestone, all ceased to exist, with the exception of one or two families of zoophytes and testacea. Instead of the black-band iron- stone, the source of our chief metallic wealth and power, gypsum and rock-salt are produced, and stored up in a few rare localities. The formation is widely spread over every quarter of the globe; and the changes in the vegetable and animal economy, as indicated by the changes in the mineral kingdom, appear to have been equally universal. But once again, in the altered state of things, nature was preparing for new forms of life and new types of animal existence, while she was parting with so many of the old races, which had so admirably subserved the purposes of their creation. One remarkable change in the laws of functional structure is here, for the first time, observable ; namely, the substitution in fishes of the homocercal for the heterocercal form of the tail-fin. This organ in the fishes of all the former epochs of the earth's history is unequally lobed, — as still preserved in the shark and sturgeon, — in conse- kxvi GEOLOGY OF SCOTLANL. quence of the vertebral column extending to the extremity; whereas, from this period downwards, and in all existing families, with the exceptions noticed, the back- bone terminates ivithin the fin, and thereby Causes it to be equally lobed, as seen in the cod, herringj and salmon. The impressions of bird and reptilian foot-marks are alsoi very abundant in this series of rockSi Here, likewise, are the first traces of oviparous quadrupeds, in the remains which have been found of the protosaurus and phytosaurus. The foot-prints in some places, especially in Pennsylvania, Connec- ticut, and Virginia, are very abundant, consisting of small toe-like scratches, deep; palmy impressions, and large tridactyle hollows, which measure eighteen inches in length, by fourteen in breadth ; and in some localities, so numerous are these curious lithographs, as to indicate a place of general resort, probably upon the . retiring of the tide in quest of prey, where lines^ and tracts are observed to cross and re-cross each other in every direction. Many of the strata are covered with the ripple and other water-marks, suggestive of the retreating wave and shelving shore; and very frequently they are indented with little circular spots, imputed to the pattering of the rain. In the Stonesfield slate, near Oxford, and in the sand- stones of i Sussex and Dorsetshire, the trail and petrified castings of marine worms, perfectly preserved, have been detected, impressed on the sand while it was yet soft on the sea-shore. Nor, among these singular hieroglyphics, are the least singular the tubular cavities in which the molluscs themselves must have resided, the forms of the creatures being distinctly traced at the upper extremity of the holes still preserved in tlie rock. The fossil impressions in the sandstone of Dumfriesshire are equally well defined in the only two localities in which they have been found- namely, Cocklemuir, in the parish of Lochmaben, and Locherbriggs quarry, near the town of Dumfries. They consist, in the former locality, of the foot-prints of some four-footed reptilian, where the alternate movements of the right and left pairs are parallel, and at regular distances from each Other. The impressions are about two inches in diameter, by half an inch in depth; and in the other locality they have obviously been produced by the passage of birds over the soft sand, generally small, but perfect in' their outline, and even the scratchings of the sharp claws distinctly legible. What a curious reading all this, in these chronicles' of ancient geolojgic times! How singular the preservation of such ephemeral impressions as the trail of a worm, the tread of a reptile, the foot-print of a bird, mingled with indicia of the state of the atmosphere, the direction of the winds,'the ripple of the waves, and the flow of the tides! Preserving something of the 'old, and introducing so many new traces of organic life, especially those of birds and oviparous quadrupeds, the new red sandstone has been regarded as the transitional boundary between the- lower and upper secondary strata, and serves to mark' a period of comparative inactivity in the physical causes by which, from time to time, the state of the mineral, vegetable, and animal departments of nature have been so much influenced, modified, and finally changed. Accordingly, one of these changes, upon a great scale, appears to have taken^ place upon th& mtroduction of the next series of superincumbent strata These are germed the lias, oolite, wealden, and chalk groups, in which we have not onlv a different set of rocks, but also different races of plants and animals. Instead of magnesian limestone, there are dark argillaceous and calcareous beds of rock- for variegated gypseous and saliferous marls, there are blue pyritous clays ; and in ^1 ace of red and mottled sandstones, there are bands of coal, and dark-coloured bitumi- nous shales. Nor m the organic products are the differences less striking The sea GEOLOGY OF SCOTLAND. Ixxvii now swarmed with new and strange forms of life^ creatures sixty to a hundred feet in length— the; icthyosatiriaies and plesiosaurians. The land was again covered with a rieh /vegetationy generally different, hut approaching to the rank luxuriance of the carhouiferous age, and accompanied with- animals of corresponding, bulk— iguanadons, hylseosaurians, and ) pterodactyles^fit to; swim in .the slimy lagoons, or to perch on trees,: in search of- food and prey. And, every where in, ithe waters there were coralline and shelly bodies, many of them infinitesimally small^rbut so incon- ceivably numerous as to form, by; their skeletons alone^ masses of rock, several hundred feet thick) and thousands, of miles in extent. ; These teachings of geology forcibly, again, support the truths of Natural Theology, showing, in -such vast changes the direct interposition of Divine might;' and,- in the beautiful adaptive arrangements thencfr arising, the constant superintendence of the, great First Cause. This series of rocks,; comprising under each group a great diversity