mew mere eal eye ere 2 eA hy Peery yea weed Der tien soe 7 CORNELL UNIVERSITY LIBRARY ENGINEERING LIBRARY = — [i ee ee es ese es 0 | le oe Orme aeons tee fe Oat as “GITYOM BHL 40 dVW IVOISAHd d 1 Ted a THE EARTH AND MAN: a LECTURES ON COMPARATIVE PHYSICAL GEOGRAPHY, IN ITS RELATION TO THE HISTORY OF MANKIND. BY ARNOLD GUYOT, LATE PROF. OF*PHYSICAL GEOGRAPHY AND HISTORY, AT NEUCHATEL, SWITZERLAND. TRANSLATED FROM THE FRENCH, BY C. C. FELTON, PROPESSOR [IN HARVARD UNIVERSITY. ww * Our Earth is a star among the stars; and should not we, who are on it, prepara ourselves by it for the contemplation of the Universe and. its Author? —Caru Rirrer. SIXTEENTH THOUSAND. - BOSTON: GOULD AND LINCOLN. NEW YORK: SHELDON AND COMPANY. CINCINNATI: GEO. 8. BLANCHARD. 1865. Zotered according to Act of Congress, in the year 1849, By Goutp, Kenpaut & Lincoin, : Lo the Clerk’s office of the District Court of the District of Massachtsetts, To C. C. FELTON, Esq, Professor in Harvard University, Cambridge. My Dear Sir, It is to your friendship that I owe the idea and the possibility of ppblishing this little work in a language not my ¢wn. With rare kindness, and a disinterestedness still more rare, you ‘nave placed at my disposal your hours of leisure and your skilful and inde- fatigable pen. The book is yours already, and I but renew your title to it by begging you to accept this pepicaTion, as a testimony of my heart-felt gratitude, and at the same time as a scuvenir of the long but pleasant hours of labor which you hae so kindly sha ed with me to the last. THE AUTHOR PREFACE. Tnx lewurea «wiined in the volume here offered to the pub lic were delivers, try invitation, in French, between the 17th of January and the 24th of February, of the present year. One of the halls of the Lowell Institute, in Boston, was placed, for that purpose, at the author’s disposal, by the liberality of the Trus- tee, John A. Lowell, Esq. They were spoken with the help only of a few notes, and were not intended, at the time, for the press. But the publication having been desired by some friends, and requested by the editors of the Boston Daily Traveller, for the columns’ of that excellent journal, the author determined to write out, the next morning, the lecture of the evening before. These rapid pages, translated, from day to day, by Mr. C. C Fel- ton, Professor in Harvard University, are collected and reprinted in the present volume. Neither time nor circumstances have per- mitted any important alterations ; the only material additions are found in the first lecture, the last part of which did not appear in the journal, and, at the beginning of the eighth, the portion which treats of the marine currents. This subject, although announced in the programme of the course, it was found necessary, for want of time, to pass over in silence. As to the rest, the lectures have retained their original cast, notwithstanding the incongruity which sometimes happens, of bringing several different subjects into the same diszourse. 1* 6 PREFAUE. This brief history of the present book will place the reader in a position to form a just opinion of the work, and perhaps wil) induce him to extend to it some indulgence. It will, moreover, be readily understood, that oral instructior is naturally clothed in forms appropriate to itself, which are not those of a systematic and didactic exposition, such as is required by a book intended only for reading, or for the silent study of the closet. In the opinion of the author, it should bring out ir strong relief, even by venturing a dash of the pencil somewhat bold, the essential traits of the subject, in order to fix and deepen the impression, while the secondary features are thrown into the shade. ‘Truth, far from losing by this mode, will gain the advan- tage of being grasped in a manner at once more distinct and more correct. For nothing is less indispensable to true science, — may the reader of these pages find it so, —than the scholastic and doctoral robe, which is too often unnecessarily worn. This little work is not, then, a treatise on the subject indicated by its title. The author would wish to consider this unforeseen publication only as the forerunner of a more complete work, the materials of which, gradually collected during long years of study, and still daily accumulating, he hopes to arrange, and work out more at leisure, if not in the same form, at least in the same spirit. However, he is confident that the man of science will find, in this first sketch, the traces of serious and matured studies. Numerous quotations and references were incompatible with the form of these discourses. The facts, properly so called, are drawn from the common domain of science ; and as to the results that have been deduced from their combination, the author wil- lingly leaves to men versed in the subject the task of distinguish- ing those which may be regarded as constituting a progress in knowledge of the creation, and of its relations to man. There are, however, three names so closely connected with the history of the science to which this volume is devoted, and with the past studies of the author, that he feels bound to mention them here Humboldt, Ritter, and Steffens, are the three great PREFACE. 7 minds who have breathed a new life into the science of the phys. ical and moral world. The scientific life of the author opened under the full radiance of the light they spread around them, and it is with a sentiment of filial piety that he delights to recall this connection, and to render to them his public homage. Notwithstanding the praiseworthy care the publishers of this volume have taken to provide it with the maps and drawings necessary to understand the text, the reader will perhaps desire more. He will find them in the Physical Atlas of Berghaus, the most excellent, and almost the only work of the kind, or in the English publications based on it, by Johnston of Edinburgh, by A. Petermann of London, and others. The explanatory pages zive the information necessary for the plates that accompany these sheets. Jor their execution on stone, the author deems himself happy in having been able to avail himself of the talents of an artist so able and obliging as M. Sonrel. Besides Prof. Felton, who has read all the proof-sheets, the author returns his sincere acknowledgments to Professors Agas- siz, Peirce, and Gray, who have had the goodness to revise por- tions of them. Few subjects seem more worthy to occupy thoughtful minds, than the contemplation of the grand harmonies of nature and history. The spectacle of the good and the beautiful in nature, reflecting everywhere the idea of the Creator, calms and refreshes the soul. The view of the hand of Providence, guiding the chariot of human destinies, reassures and strengthens our faith. May these unpretending sheets, launched upon the sea of publicity, reach those who feel the need of both, and by them be kindly received. Camprivce Mass., May 1, 1849 PREFACE TO THE SECOND EDITION Tae marked favor with which the public, here and abroad,* have received this essay, imposed on the author the duty of care- fully revising it. ‘But the time of its first appearance is so recent, that no important alterations are to be made. Except a few addi- tions of facts quite recently acquired for science, particularly in the paragraph relating to the sub-marine relief of the basin of the oceans, the work has remained, in substance, what it was. Not so with the translation. The translator, exercising a severer crit- icism than the reader upon his own work, has carefully revised, improved, and corrected it; and the author seizes this occasion to repeat his thanks for this fresh endeavor to render these sheets more worthy of the public approbation. If there is any reward worthy of desire to him who communi- cates his thoughts to his fellow-men, it is that of meeting, in the midst of throngs preéccupied with so many diversified cares, an echo and sympathy. This gratification has not been wanting to the author, and he recalls with-pratitude the numerous testimonies he has received from so many. quarters. He finds in these mani- festations an encouragement to continue his work, and to prepare a second volume, on the Historical Development of Humanity, which he considers as the necessary complement to the present. Campringe, July, 1850. * This volume has been republished in London, by Bentley, and an edition in French is about to appear at Paris. A mutilated edition, called ‘ revised,” has also been published by E. Gover, Sen., London, in which maby passages, aluounting to over thirty pages of the original edition, and essential to the con. tinuity of the argument, or containing conclusions, have heen suppressed ; additions have been inserted expressing views not advanced by the author; alterations have heen made, in exceedingly bad English, all without the least intimation in the preface. Against the two first, the author protests ; against the last, the translator. EXPLANATION OF THE PLAZES AND FIGURES PLATE I. Puysican Mar or tHe Worn. Tuts map, in Mercator’s projection, is intended to enable the eye to seize at a glance the great physical features of the surface of the globe. To this end, each particular is indicated by a different color. The color of the ocean forms a ground which clearly defines and brings out the characteristic forms of the continents. The bands of white lines which cross them indicate the course of the marine currents, according to the Physical Map of Berghaus. The arrows mark their direction. In the continents, three colors distinguish the three principal forms of relief from each other. The green tint marks the low lands; the white, the more elevated parts and the table lands; the brown, the systems of mountains, the borders of the table lands, and the slopes in general. It is easy thus to form by @ single glance an idea of the general features of relief of the different countries of the earth. The dotted lines which cross the map are, beginning at the top, the Arctic circle, the tropic of Cancer, and the tropic of Capricorn. The entirely straight line is the Equator. The latitudes are marked in the margin by a line for every 15°. The longitudes in the same way, by 15° East and West from the meridian of Paris. The two winding lines in the northern half of the map are the isothermal lines of zero Centigrade or.32° Fahrenheit, and of 15° Centigrade or 59° Fahrenheit. All the places situated on these lines, having the same mean annual temf«ra- ture, get in a clear light the difference of climate between the opposite coasts of the continents, while referring it to the true causes. Evely letter has been omitted from this little map, which is intended to be a physical picture, and to speak to the eye. The scale, moreover, searcely allowed their insertion, and the great features which it repre sents are so well known that there is no need of naming them. 10 EXPLANATION. a PLATES II.-AND II. (pp. €0, 61.) These plates contain a series of ideal profile. intended to illustra’ the general laws of relief of the continents. ‘ne profiles comprise each a transverse zone rather than a simple line, which often would have answered but imperfectly the propesed end. The relation of the heiglits to the horizontal distances would have to be magnified abeut ene hundred times. The numbers placed in the margin, indicate the heights in thousands of feet. The letters placed at the top of the verti cal dotted lines, are the initials of the names of the principal pointy contained in the tables; when the same initial is repeated, the second in the order of the table is marked thus: (?). The profilesof the massive and entire parts of the continents, comprising the plains and table lands, are distinguished from the heights which surround them, or the mountain chains, by a particular line, by different hatchings, and deeper shading. The peaks, which are merely indicated above the base line, without being connected, are either mountains situated outside of the zone, followed by the profile, as the Carpathian and Mont-Blanc, in Europe, Plate II. profile 5 ; or volcanic peaks, isolated, not affecting the general relief, as the Erdschich, in Asia Minor, Plate iI. profile 4; the Ararat, in Armenia, Plate III. profile 1. Plate II. wofile 3; the St. Elias, in North America. _ Plate IJ. comprises 7 profiles across the three principal continents of he Old World, in the direction from north to south. In profile 1, Saustern Asia, and profile 6, Africa, the line of horizontal distances xeing too considerable to be taken into the frame, the profiles are inter- vupted to indicate that one portion of the horizontal line has been suppr ssed. In the profile of Eastern Asia the portion omitted is almos equal to the less section. In Africa it is much larger still. Plate III. comprises the profiles of the New World, from east to west. No. 2, passing along the line of the Antilles, is necessarily broken. But the gradual increase of the, reliefs and their disposition prove that this line ought to be considered in reality continucus, although at some points it is covered by the waters of the ocean. The profiles are arranged in the plates in such a manner as to show, at once, in the vertical line, the increase of the reliefs fiom west to east in the Old World, and from north to south in the New World. The test itself m«kes further explanatior tnnecessary. EXPLANATION 11 PLATE IV. Mai or rue Disrripution cr Ratn. This map, takew. from the Physical’ Atlas of Berghaus, shcws the distribution of rain on the surface of the globe. The deeper the co.or, tke greater is the quantity of rain-water indicated ; the deserts are left in white. North and south of the tropics, which site marked by dotted nes, are the regions of continuous, but not abundant rains. Be.:ween the tropics, the region of periodical and copious rains. A little north of the Equator a deeper shaded strip indicates the region of calms, where daily thunder storms cause almost eaten out the year the fall of a considerable quantity of water. PLATES V. AND VL, Intended to illustrate the law of the degeneration of the human type in leaving the central region of Western Asia, comprise 16 portraits, all drawn from nature, and taken from the plates of the “ Animal Kingdom ” of Cuvier, wherever a different source is not indicated. Pirate V. First Series. From the central regions of Western Asia, to the extremity of Africa, through Arabia and the eastern coast. No. 1. A Circassian, belonging to the suite of the Persian Amlzs- sador; drawn from the life, at Paris, in 1823, by M. A. Colin. No. 2. An Arab of Algiers, of the Mozabite tribe drawn from life, under the direction of Mr. Milne Edwards, by A. Lordon. No. 3. A negro of Mozambique, on the south-east coast of Africa ; drawn from life, in Brazil, by Rugendas. » No. 4. Joshua Makoniane, an old Bassouto warrior, a convert to Christianity, drawn from life by Mr. Maeder, of the French Mission to South Africa. Journal des Missions Evangeliques de Paris, Vol. XX. Second Series. From Europe to tropical Africa, by the western coast. No. 5. Portrait of Captain Cook, painted by Dauce, in the gallery of the Naval Hospital at Greenwich. Geographical Almanac of Berghaus. No. 6. A Cabyle of Flissa, in Algeria ; ; drawn from life by A. Ls rdon. No. 7. Senegal Chief, after an unpublished drawing by an officer in the expedition of Captain Laplace. No. 8. A Negroof Corgo; drawn from nature by Rugendas, Voyage Pittoresque au Brési. Puate VI. First Series. No. 1. Mongolian type portrait of one of the Siamese twins ..een tn Europe in 1830, after . drawing made from nature, at Paris. 12 EXPLANATION. No. 2. Malay, belonging to the group of the Kouti usoff Smolensky, from a plate in the work of Choris, Voyage du Rurick. No. 3. NewHolland. Portrait of Onrou-Mare, a warrior of the tribe of the Gwea-Gul, from the Atlas du Voyage aux Terres Australes. No. 4, A woman of Van Diemen, from )’Atlas de ]’ Astrolabe. Second Series. America, from the sources of the Missouri to Terra del Fuego; and the Polar variety. No. 5. Oto Indian, portrait taken from the Travels of Prince May- imilian of Neuwied. No. 6. Coroado Indian, from the banks of the Rio Xipoto, one of the tributaries of the Rio Pomba, in tropical South America, after a portrait published by Spix and Martius. No. 7. An inhabitant of Terra del Fuego; Univers Pittoresque. No. 8. Inhabitant of the Aleutian Islands, after Choris; Voyage of Kotzebue. Fig. 1. page 43. Land Hemisphere, and Water Hemisphere. Fig. 2. page 106. Europe at the Silurian Epoch. Fig. 3. page 108. America at the Coal Epoch. Fig. 4. page 111. Europe at the Tertiary Epoch. These three last maps, intended to poe the gradual increase of the dry lands, do not so much indicate the real contours of the lands exist- ing at those epochs,—this would be impossible,— as the portions which have not since been covered by the waters of the ocean. The white portions are the only dry land. All the portions in ruled nes are under water; but the existing contours of the continents are iepre- sented by means of a lighter shade, as a point of comparison. The maps Fig. 2, and Fig. 4, have been constructed after the geological maps of Elie de Beaumont, (in Beant géologie,) Boué, and Dechen; the map Fig. 3, after the geological map of the United States, by Mr. James Hall, completed by that of Sir Charles Lyell and the geological map of the world, by Boué. CONTENTS. LECTURE I. Subject of the coirse— What should be understood by Geograj hs -— Definition of Physical Geography — The life of the globe — Impor- tance of the geographical forms of contour and relief, end of their relative situation —The Earth as the theatre of human societies — Different parts performed by the continents in history — Asia, Europe, America — Inquiry into the analogies of the general forms of the continents. . 7 é A y j . 7 Pi s . iy LECTURE II. Recapitulation — Vertical dimensions or forms of relief— Difficul- ties presented by their study — Usefulness of profiles — Great influence of differences of height — Elevations in mass, and linear elevations — Importance of the former-— Labors of Humboldt and Ritter on this subject — Examination of the general features of relief of the conti- neits—-.A great common law embracing them all. : ‘ 4s 2 140 CONTENTS. LECTURE III. ‘Distribution of the table lands, the mountains, and the plains o the different continents ;.the Old World that of plateaus, the New World that of plains — The basin of the oceans; this inquiry completes the study of the plastic forms of the earth’s crust— Division and char- acteristics of the oceans ; their contours and their depth — Compat:son ot the latter with the mean elevation of the continents — Ccnclusions — Necessity of considering the physiology of the continental forms — Point of view which should be taken — Law of the development of life. . . . : . ‘ : . . . . - LECTURE IV. Recapitulation—Is the law of development applicable to the whole globe, considered as an individual ? — Origin of the Earth, according to the hypotheses of Laplace and Herschell — Gradual formation of th: continents — Europe at the Silurian epoch— North America at the Carboniferous epoch — Character of inferiority of the organized beings which correspond to these ancient formations — Europe at the Tertiary epoch — Greater diversity and perfection of the organized beings — Distinction of the three epochs; the insular, the maritime, and the continental The formula of development the same for the entire globe and for the organized beings —Consequences— The law of differences and the law of contrasts—The three grand terrestrial eontmsts; © # « « © » » ww w« «@ © 1060 LECTURE V. The North-east or Continental hemisphere, and the South-west o1 Oceanic hemisphere — Land and water — Differences in the forms of their surfaces —Continental climate and sea climate — Their different influences upon the vegetation and organized beings— The oceanic the inferior element; the terrestrial element the superior — Blending of the two natures — Transportation of the waters of the ocean into the continents — The atmosphere the mediator between them. . . 118 CONTENTS. 1 Bs) LECTURE VI. The study of the distribution of the rains supposes that of the winds — Difference of temperature the principal cause of the winds — Theory of the general winds—The winds of the tropical regions — Trade winds of the Pacific Ocean — Trade winds of the Atlantic — The monsoons of the Indian seas—The winds of the temperate vegions — Two general currents; the return trade wind, or equatorial wind, and the polar currents— The conflicts of the two, and the variable winds — Lateral displacement of the currents, and their influ- ence upon the temperature, the productions of the soil, and commerce —The law of the rotation of the winds—The atmospheric water falling back into rain— Circumstances favorable to the precipitation of vapors — The rains of the tropical zone— The rains in the region of the monsoons— Annual quantity of the rain-water under the tropics — Distribution and annual quantity of the rain in the temperate regions. . ;: . . 3 . : . . . 132 LECTURE VII. Modifications of the general laws of distribution of the rains — Decrease of the quantity of rain waters and of rainy days, from the sea-board towards the inlands—Numerous exceptions, and their tauses— Influence of the mountains and the table lands in the two worlds — Distribution of rain in South America; in. North America ; in Africa; in Europe; in Asia; in Australia — Special hygrometrical character of each continent — Difference between the Old and the New World, corresponding to the nature of their relief — Mixture of the ccntinental and the oceanic element — Influence on organized beings — Superiority of the zone of contact, or the maritime zone. +60 16 CONTENTS. LECTURE VIII. The marine currents — The motion of the seas due to other causes ihan that of the ccntinental waters—Various causes of the marine currents — Differences of temperature the principal, acting indirectly by the winds, directly by the unequal density of the waters — Coinci- dence between the great“atmospheric currents and the marine currents — System of general currents — The Equatorial current and the Polar currents — The currents of the Pacific Ocean; of the Indian Ocean ; of the Atlantic Ocean — Contrast of the Old World and the New — Disposition of their continental masses — Consequences—The Old World the Continental; the New the Oceanic— The first essentially temperate, the second tropical — Special character of the New World — Its structure more simple— Abundance of its waters —Vegetation predominates on the Animal World—Incomplete development of the higher animals — Influence on the indigenous man —Conclu- sions. ‘ . 7 é ‘ é e é ‘ ‘ ‘ 186 LECTURE IX. Geographical characteristics of the Old World — The Continent of Asia-Europe — Comparison of its structure with that of America — The continental climate prevailing in the Old World — Consequences —Vegetation less abundant — Preponderance of the animal world -~ Ihe Old. World the country of the higher and historical races — Reciprocal action of the two worlds by means of man — Establish- ment of the man of the Old World in the New — Historical America compared with Europe — Alliance of the two worlds ; solut‘on of the eentrast . . . . . c * - 219 CONTENTS. 17 LECTURE X. Contrast of the three continents of the North and the three conti- nents of the South— Physical characteristics of the two groups; the fcrner more articulated, more consolidated, more similar; the latter nwre entire, more isolated, more different— These differences and anologies reproduced in the vegetation and the animal world — The three continents of the North temperate; the three of the South topical — Superiority of the tropical climate in nature — Gradual increase of life, of the variety and improvement of the types of organ- ized beings, in proportion to the warmth, from the poles to the equa- torial regions — Man alone forms an exception— Law of the dis- tribution cf the human races — Geographical centre of mankind marked by the race of the highest perfection — Gradual degeneracy of the human type towards the southern extremities of the continents —The geographical distribution of the races of man and the animals tounded upon a different principle— Advantage of the temperate climate for the improvement of man. . * s . 240 LECTURE XI. The continents of the North considered as the theatre of histor} — A@ta-Europe; contrast of the North and South; its influence in history; conflict of the barbarous nations of the North with the civi ized nations of the South—Contrast of the East and West — Eastern Asia a continent by itself and complete; its nature; the Mongolian race belongs peculiarly to it ; character of its civilization —Superiority of the Hindoo civilization ; reason why these nations have remained stationary —— Western Asia and Europe; the country of the auly historical races — Western Asia ; physical deseription ; its historizal character : Europe — the best organized for the development of man and of societies ; Rmerica — future to which it is destined by uts physica] nature. : s 6 3 : mee 272 Qx 18 CONTENTS. LECTURE XII. Geographical march of history — Asia the cradle of civilizaucn — Common character of the primitive nations — Powerful influence of nature — The human race in its infancy lives under authority, whica becomes slavery — Civilization passes to Europe — Greece ; period of youth ; emancipation, and intellectual and moral development ; action on the East and West; the Greek the teacher of the world — Rome ; her work political and social—Inability of the Ancient World to attain the end of humanity — Coming of Christ ; his doctrines new in a historical’ point of view—The Germanic Christian world begins their application — Civilization passes to the North, and embraces all Europe ; its different phases—— Europe owes it to the rest of the world — Discovery of America— Universal inroad of the civilized nations — Social work begun at the same time — America must finish it—-The people of the future; by what signs recognized — Conclu- sions — Foreseen solution of the contrast of the three Northern conti- nents and the three Southern — Duties of the privileged races towards the ‘nferior---A few words upon the method pursued — Science and faith, «6 6 6 ee et . 296 THE EARTH AND MAN. - AGT. LECTURE I. Subject of the course— What should be understood by Geography — Definiten af Physical Geography — The life of the globe — Impor- tance of the geographical forms of contour and relief, and of their relative situation — The Earth as the theatre of human societies — Different parts performed by the continents in history — Asia, Eu rope, America — Inquiry into the analogies of the general forms of the continents. Lapres anp GENTLEMEN : — In asking your attention to a few scientific discourses, in a language not your own, I have not disguised from myself that this circumstance is perhaps a source of embarrassment for some of you, as it certainly is for me. In the communion of mind with mind, in the mutual interchange of ideas, the first condition necessary for establishing between him who speaks and those that hear, the sympathetic harmony which makes its charm, is, that the word shall reach the understanding without obstacle and without effort. Tn my favor you have made the sacrifice of your lan- guage. I need not tell you, that, on my part, I will do 20 COMPARATIVE PHYSICAL GEOGRAPHY. all in my power to render that sacrifice less irksome, and I shall always be desirous of giving to those who will do me the favor to.ask it, all the explanations which they can require. The subject to which I propose to call your attention, is Comparative Physical Geography, considered in its relations to the history and the destinies ef mankind. But the term geography has been applied to such dif- ferent things, the use, the misuse rather to which it has been subjected, has rendered it so elastic and ill-defined, that, in order to prevent misconception, I must first of ail explain to you what I understand by Greography. If, preserving the etymological sense of the word: geography, we should, with many authors, undertake ta limit this study to a simple description of the surface of the globe and of the beings which are found ‘there, we we must at once renounce the idea of calling it by the name of science, in the lofty sense of this word. 'To describe, without rising to the causes, or descending to the con- sequences, is no more science, than merely and simply to relate a fact of which one has been a witness. The geographer, who thus understands his study, seems to make as little of geography as the chronicler of history. It would be easy to show that even the power of describing well ought to be denied him; for if he re- neunces the study of the laws which have presided over the creation, over the disposition of the terrestrial indi- viduals in their different orders: if he will take no ac- count of those which have given birth to the phenomena that he wishes to describe, soon, overwhelmed beneath the mass of details, of whose relative value he is igno- INTRODUCTION. 21 rant, witnout a guide and without a rule to make a judicxous choice in the midst of this infinite variety of partial observations, he remains incapable of mastering them, of grouping them in such a manner as to bring prominently forward those which must give character to the whole, and thus dooms himself to a barren confusion at least; happy, if, in place of a faithful picture of na- ture, he does not finally profess to give us, as such, the strangest caricature. No! Geography —and I regret here that usage for- bids me to employ the most suitable word, Geology, to designate the general science of which I speak — Geog- raphy ought to be something different from a mere description. It should not only describe, it should com- pare, it should interpret, it should rise to the how and the wherefore of the phenomena which it describes. It is not enough for it coldly to anatomize the globe, by merely taking cognizance of the arrangement of the various parts which constitute it. It must endeavor to seize those incessant mutual actions of the different por- tions of physical nature wpon each other, of inorganic, nature upon organized beings, upon man in particular, and upon the successive development of human societies, in a word, studying the reciprocal action of all these forces, the perpetua. play of which constitutes what might be called the lif: of the globe, it should, if I may venture to say so, inquire into its physiology. To understand it in any other way, is to deprive geography of its vital principle; is to make it a collection of partial, unmean- ing facts, is to fasten upon it forever that character of dryness, for which it has so often and so justly been 22 COMPARATIVE PHYSICAL GEOGRAPHY. reproached. For what is dryness in a science, excep* the absence of those principles, of those ideas, of chose general results, by which well-constituted minds are nurtured ? Physical geography, therefore, ought to be, not cnly the description of our earth, but the physical science of the globe, or the science of the general phenomena of the present life of the globe, in reference to. their connec- tion and their mutual dependence. This is the e geography of Humboldt and of Ritter. But I speak of the life of the globe, of the physiology of the great terrestrial forms! ‘These terms may per- haps seem here to be misapplied. I ask your permission to justify them, for I cannot find better, to express what appears to me to be the truth. Far from me the idea of attempting to assimilate this general life of the inorganic nature of the globe to the individual life of the plant or the animal, as some unwise philosophers have done. I know well the wide distance which separates inorganic from organized nature. I will even go further than is ordinarily done, and I will say that there is an impassable chasm be- tween the mineral and the plant, between the plant and the animal, an impassable chasm between the animal and the man. But this nature, represented as dead, and contrasted in common language with living nature, because it has not the same life with the aniwal or the plant, is it then bereft of all life? If it has not life, we must acknowledge that it has at least the appearances of life. Has it not motion in the water ‘vhicl. streams 2nd gushes over the surface of the con- INTRODUCTION. 23 tinents, or which tosses in the bosom of the seas?- -in the winds which course with terrible rapidity and sweep the soil that we tread under our feet, covering it with tuins? Has it not its sympathies and antipathies in those mysterious elective affinities of the differcnt molecules of matter which chemistry investigates? Has it not the powerful attractions of bodies to each other, which govern the motions of the stars scattered in the immensity of space, and keep them in an admirable harmony? Do we not see, and always with a secret astonishment, the magnetic needle agitated at the ap- proach of a particle of iron, and leaping under the fire of the Northern light? Place any material body what- soever by the side of another, do they not immediately enter into relations of interchange, of molecular attrac- tion, of electricity, of magnetism? ‘The disturbance of the equilibrium at one point induces another elsewhere, and the movement is propagated to infinity. And what will it be, if we rise to the contemplation of all the phenomena of this order together, exhibited by a vast sountry, by an entire continent ? Thus, in inorganic nature likewise, all is acting, all is changing, all is undergoing transformation. Doubt- less this is not the life of the organized being, the life of the animal; but is not this assemblage of phenomena also a life? If, taking life in its most simple aspect, we define it as a mutual exchange of relations, we cannot refuse this name to those lively actions and reactions, to that perpetual play of the forces of matter, of which we are every day the witnesses. Yes, gentlemen, it is indeed life, but undoubtedly in a very inferior order of things. 24 COMPARATIVE PHYSICAL GEOGRAPHY. It is life; the thousand voices of nature which make themselves heard around us, and which in so many ways betray that incessant and prodigious activity, proclaim it so loudly that we cannot shut our ears to their language. This general life, this physical and chemical life, be- longs to al] matter. It is the basis of the existence of all superior beings, not as the source, but as the condi tion. It is in the plant, it is in the animal; only here it is subservient to a principle of higher life of a sviritual nature, of a principle of unity, the mysterious force of which, referring all to.a centre, modifies it, controls it, and organizes it, for the benefit of an individual. Now it is precisely this indernal principle of unity belonging to organized nature, which is wanting in in- dividuals of inorganic nature; and that is the difference. In inorganic nature, the bodies are only simple ag- gregations of parts, homogeneous or heterogeneous, and differing among themselves, the combination of which seems to be accidental. Nevertheless, to say nothing of the law that assigns to each species of mineral a par- ticular form of crystallization, we see that every aggrega- tion, fortuitous in appearance, may constitute a whole, with limits, and a determinate form, which, without having anything of absolute necessity, gives to it, how- ever, the first lineaments of individuality. Such are the various geographical regions, the islands, the peninsulas, the continents ; the Antilles, for example, England, Italy, Asia, Europe, North America. Each of these terrestrial masses, considered as a whole, as an individual, has a particular disposition of its parts, of the forms which INTRODUCTION. 25 belong only t¢ it, a situation relatively to the rays of the sun, and with respect to the seas or the neighboring masses, not found identically repeated in any other. All these various causes excite and combine, in a manner infinitely varied, the play of the physical forces inherent in the matter composing them, and secure to each a climate, a vegetation, and animal life; in a word, an assemblage of physical characters and func- tions peculiar to it, and really giving it something of individuality. It is in this sense that we shall speak of the great geographical individuals, that We shall be able to define them, to indicate their characters, to mark their differ- ences; in a word, to apply to them that comparative study, without which there is no true science. But let us not forget that these individuals have the cause of their existence, not within, like organized beings, but without, in the very circumstances | of their aggregation. Hence, gentlemen, the great importance of external form; the importaiuce of the geographical forms of con- tour, of relief of the terrestrial surface; of the relations of size, of extent, of relative position. In considering them simply in a geological point of view, it may appear quite accidental that such a plain should or should not have risen ‘from the bosom of the waters; that sucha mountain rises at this place or that; that such a con- tment should be cut up into peninsulas, or piled into a compact mass, accompanied by, or deprived of, islands. ‘When, finally, we reflect that a depression of a few hundred feet, which would make no change in the essential forms of the solid mass of the globe, would 3 26 COMPARATIVE PHYSICAL GEOGRAPHY. cause # great part of Asia and of Europe to disappea beneath the water of the oceans, and would reduce, America to a few large islands, we might be led to the conclusion that the external shape of the continents has but an mconsiderable importance. : But, in physics, neither of these circumstances is unimportant. Simple examples, without further dem- onstration, will be sufficient to set this in a clear light. Is the question of the forms of contour? Nothing characterizes Europe better than the variety of its indentations, of its peninsulas, of its islands. Suppose, for a moment, that beautiful Italy, Greece with its entire Archipelago, were added to the central mass of the continent, and augmented Germany or Russia by the number of square miles they contain; this change of form would not give us another Germany, but we should have an Italy and a Greece the less. Unite with the body of Europe all its islands and peninsulas into one compact mass, and instead of this continent, so rich in various elements, you will have a New Holland with all its uniformity. Do we look to the forms of relief, of height? Is it a matter of indifference whether an entire country is lifted into the dry and cold regions of the atmosphere, like the central table land of Asia, or is placed on the level of the ocean? See, under the same sky, the warm and fer- tile plains of Hindoostan, adorned with the brilliant vege- tation of the tropics, and the cold and desert plateaus of Upper Tubet ; compare the burning region of Vera Cruz and its fevers, with the lofty plains of Mexico and its perpetual spring; the immense forests of the Amazon, INTRODUCTION. 27 wiiere vegetation puts forth all its splendors, and the deso.ate paramos of the summits of the Andes, and you nave the answer. And the relative position? Do not the three penin- sulas of the South of Europe | owe to their position their mild and soft climate, their lovely landscape, their numei- ous relations, and their common life? Is it not to their situation that the two great peninsulas of India are in- debted for their rich | niture, and the conspicuous part one of them, at least, has played inall ages? Place them on the north of their continents, Italy and Greece become Scandinavia, and India a Kamtschatka. All Europe is indebted for its temperate atmosphere to its position relatively to the great marine and atmos- pheric currents, and to the vicinity of the burning regions of Africa. Place it at the east of Asia, it will be only a frozen peninsula. Suppose the Andes, transferred to the eastern coast ot South America, hindered the trade wind from bearing the vapors of the ocean into the interior of the continent, and the plains of the Amazon and of Paraguay would be nothing but a desert. Tn the same manner, if the Rocky Mountains bordeied the eastern coast of North America, and closed against tae nations of the East and of Europe the entrance to the rich valley of the Mississippi; or if this immense chain extended from east to west across the northern part of this gontinent, and barred the passage of the polar winds, which now rush unobstructed over these vast ‘plains; —let us say even less: if, preserving all the great present features of this continent, we suppose only that 28 COMPARATIVE PHYSICAL GEOGRAPHY. the intzrior plains were slightly inclined towards the north, and that the Mississippi emptied into the Frozeu. Ocean, who does not see that, in these various cases, the relations of warmth and moisture, the climate, in a word. and with it the vegetation and the animal world, woula undergo the most important modifications, and that these changes of form and of relative position would have an influence greater still wpon the destinies of human socie- ties, both.in the present and in the future ? It would be easy to multiply examples; but I do not wish to anticipate the results that will be brought out by the more exact study of these phenomena, which we are about to undertake. It is enough for me to have opened a view of the important part performed by all these physical circumstances, and the necessity of study- ing them with the most scrupulous care. Let us not, then, despise the study of these outward forms, the influence of which is so evident. They are everything in this class of things. We shall see all the great phenomena of the physical and individual life of the continents, and their functions in the great whole, flowing from the forms and the. rela- tive situation of the great terrestrial masses, placed under the influence of the general forces of nature. But, gentlemen, it is not enough to have seized, in this point of view, entirely physical as yet, the functions of the great masses of the continents. They have others, still more important, which, if rightly undarstood, ought to be considered as the final end for which they have received their existence. To understand and appreciate them a‘ ‘heir full value, to study them in their true pcint INTRODUCTION. 29 of view, we must rise to a higher position. We must elevate ourselves to the moral world to understand the physical world; the physical world has no meaning except by and for the moral world. It is, in fact, the universal law of all that exists in finite nature, not to have, in itself, either the reason or the entire aim of its own existence. Every being exists, not only for itself, but forms necessarily a portion of a great. whole, of which the plan and the idea go infinitely beyond it, and in which it is destined to play a part. Thus inorganic nature exists, not only for itself, but to serve as a basis for the life of the plant and the animal; and in their service it performs functions of a kind greatly superior to those assigned to it by the laws which are purely physical and chemical. In the same manner, ll nature, our globe, admirable as is its arrange- ment, is not the final end of creation; but it is the condition of the existence of man. It answers as an instrument by which his education is accomplished, and performs, in his service, functions more exalted and more noble than its own nature, and for which it was made. The superior being then solicits, so to speak, the creation of the inferior being, and associates it to his own func- tions; and it is correct to say that inorganic nature is made for organized nature, and the whole globe for man, as both are made for God, the origin and end of all things. Scjence thus comprehends the whole of created things, as a vast harmony, all the parts of which are closely con- rected together, and presuppose each other. Yonsidered in this point of view, the earth, and all it 3% 30 COMPARATIVE PHYSICAL GEOGRAPHY. contains, the continents in particular, with the whole of their organized nature, all the forms they present, acquire a new meaning and a new aspect. It is as the abode of man, and the theatre for the action of human societies; it is as the means of the edu- cation of entire humanity, that we shall have to corsider them, to appreciate the value of each of the physica. characters which distinguish them. The first glance we throw upon the two-fold doinain of nature and of history, is enough to show that the parts performed by the different countries of the globe, in the progress of civilization, present very great differences. The three continents of the South, Australia, Africa, —I except Egypt, which scarcely belongs to it, — and South America, have not seen the birth of either of the great forms of civilization which have exercised an influence on the progress of the race. Down to times very near our own, the scene of history has hardly passed the boundaries of Asia and of Europe. Upon these two continents of the Ancient World, all the interests of the great drama, in which we are at once actors and spec- tators, is concentrated. Another continent, that of North America, has just been added, and is preparing itself to play a part of the first importance. In the earliest ages of the world, Asia shines alone. It is at once the cradle of civilization, and that of the na- tions which are the only representatives of culture, and which are carrying it, in our days, to the extremities of the world. Its gigantic proportions, the almost infinite diversity of -its soil, its central situation, would render it suitable to be the continent of the xerms, and the root INTRODUCTION. 31 of that immense tree which is now bearing such beau- tiful fruits. But Asia has yielded to Europe the sceptre of civili- zation for two thousand years. At the present day, Europe is still unquestionably the first of the civilizing continents. Nowhere on the surface of our planet has the ming of man risen to a sublimer height; nowhere has man known so well how to subdue nature, and to make her the instrument of intelligence. The nations of Europe, to whom we all belong, represent not only he highest intellectual growth which the human race has attained at any epoch, but they rule already over nearly every, part of the globe, and are preparing to push their conquests further still. Here. evidently, is the central point, the focus where all the noblest powers of humanity, in a prodigious activity, are concentrating themselves. This part of the world is, then, the first in power, the luminous side of our planet, the full-rown flower of the terrestrial globe. And yet what a contrast between this moral grandeur and the material greatness of this, the smallest of the continents! Nothing in it strikes us at the first glance. Europe does not astonish us by those vast areas which the neighboring continent of Asia embraces. _ Itseloftiest mountains scarcely reach to half the height of the Hima- laya and the Andes. Its plateaus, those of Bavaria and Spain, har lly deserve the name, by the side of those of Tubet and of Mexico. Its peninsulas, what are they in comparison with India au. Arabia, each of which forms a world by itself? Its seas, the Mediterranean and its gulfs, are far from having the proportions of the vast 32 COMPARATIVE PHYSICAL GEOGRAPHY. ocean which bathes the Asiatic peninsulas. Nowhere those great rivers, those immense streams, that water the boundless plains of Asia and America, and are their pride. Nowhere those virgin forests, which cover im- mense regions, and make them impenetrable to man; none of those deserts, whose startling and terrible aspect, under other climes, appalls us by their immensity. We see there neither the exuberant fruitfulness of the tropi- cal regions, nor the vast frozen tracts of Siberia; we feel there neither the overwhelming heats of the equator, nor those extremes of cold which annihilate all organic life. In the productions of organized nature, the same mod- esty still. The plants, the trees, do not attain to the height and growth which astonish us in the regions of the tropics. Neither the flowers, nor the insects, nor the birds,.show that variety and brilliancy of colors, which distinguish the corolla of the flowers, and the plumage of the birds, bathed incessantly in the waves of light of the equatorial sun. All the tints are softened and tem- pered down. How reconcile this apparent inferiority with the bril- liant part Europe has performed among the other con- tinents? 'This coincidence between the development of humanity in Europe, and the physical nature of this continent, can it have been only an accident? Or may this part of the world have concealed, under such modest appearances, some real superioritizs, which have ren- dered it more suitable than any other to play so distin- guished a part in the history of the world? Thisisa problem, stated by the great facts I am pointing out, the salutien of which we must seek by study. INTRODUCTION. 33 But a tnird continent, unknown in the history of ancient days, North America, has also entered the list, and is advancing with giant steps; for it has not to re- commence the work of civilization: eivilization is trans- ported thither ready made. The old natious v. Europe, exhausted by the difficulties of every kind which oppose their march, turn with hope their wearied eyes towards this new world, for them the land of the future. Men of all languages, of every country, are bringing hither the most various elements, and preparing the germs of the richest growth. The simplicity and the grandew of its forms, the extent of the spaces over which it rules, seem to have prepared it to become the abode of the most vast and powerful association of men that has ever existed on the surface of the globe. The fertility of its soil; its position, in the midst of the oceans, between the extremes of Europe and of Asia, facilitating commerce with these two worlds; the proximity of the rich tropi- cal countries of Central and South America, towards which, as by a natural descent, it is borne by the waters of the majestic Mississippi, and of its thousand tributary streams; all these advantages seem to promise its labor and activity a prosperity without example. It belongs not to man to read in the future the decrees of Provi- dence. But science may attempt to comprehend the purposes of God, as to the destinies of nations, by exam- ining with care the theatre, seemingly arranged by Him for the realization of the new social order, towards which humanity is tending wif hope. For thé order of nature is a foreshadowing of that which is to be. Such, gent emen, are the great problems our. stuay 34 SOMPARATIVE PHYSICAL GEOGRa« PHY. lays before us. We shall endeavor to solve them by studying, first, the characteristic forms of the continents, the influence of these forms on the physical life of the globe; then, the historical development of humanity. We sha... have succeeded, if we may have shown to you, 1. That the forms, the arrangement, and the distri- bution, of the terrestrial masses on the surface of the globe, accidental in appearance, yet reveal a plan which we are enabled to understand by the evolutions of history. 2. That the continents are made for human societies, as the body is made for the soul. — 3. That each of the northern or_historical continents is peculiarly adapted, by its nature, to perform a special part corresponding to the wants of humanity in one of the great phases of its history. Thus, nature and history, the earth and man, stand in the closest relations to each other, and form only one grand harmony. Gentlemen, I may treat this beautiful subject inade- quately; but I have a deep conviction that it is worthy to occupy your leisure, as it will occupy for a long time to come, if I am not mistaken, the most exalted minds, and those most ripened for elevated researches. For him who can embrace with a glance the great harmo- nies of nature and of history, there is here the most admirable plan to study; there are the past and future destinies of th2 nations to decipher, traced in ineffaceable characters by the finger 0. Him who governs the world. Admirable order of the Supreme Intelligence and Good- ness, which bas arranged all for the great purpose of FIGURE OF THE CCATINENTS. 35 the education of man, and the realization of tne plans of Mercy for his sake ! Be pleased always to remember, in my favor more than for yourselves, that the path of science is ofter diffi- cult and beset with rugged cliffs. The traveller doubt- less gathers many flowers on the way. But the tree of Science, which bears the noblest fruits, is placed high up on precipitous rocks. It holds out to our view these precious fruits from afar. Happy he who by his efforts may pluck one of them, even were it the humblest. He values it, then, by what it has cost him. [ have made the attempt, and this fruit I offer to you. In default of beauty, may you find therein the savor that I have tasted myself. After what we have just said of the importance of the geographical forms of the crust of the globe, you will not be surprised, gentlemen, that these very forms of contour and relief, although so far entirely outside, and the arrangement of the great terrestrial masses, are to be the first subject to occupy our attention. Each of these masses is a solid, of which we are not able to ascertain the configuration, except by considering it at once in its horizontal dimensions and in its vertical dimensions; that is, in its extent and m its contours; then in the varieties of relief which its surface presents. It is in this twofold point of view, and that of them relative situation, that we must first of all study them. The contours of the continents, as they are shown by the maps before your eyes, are nothing else than the delineation of the line of contact between the lands and 36 COMPARATIVE PHYSICAL GEOGRAPHY. the horizontal surface of the oceaus. ‘This line is a true curve of level, the sinuosities of which depend entirely upon the plastic forms of: the continent itself. It would change its form completely by the relative depression or elevation of the seas. Such as it is, it presents us an almost infinite variety of bends, in‘and out, which at the first glance seem perfectly irregular and accidental. Yet a more attentive study, and a comparison of the charac- teristic figures of the continents, enable us to perceive certain features of resemblance and a general disposition of their parts, which seem to indi@ate, as we shall see by-and-by, the existence of a common law which must have presided over their formation. These grand analogies, and these characteristic differ- ences of form and grouping, simple and evident as they appear to us when they have once been pointed out to our attention, have nevertheless been discovered only by degrees, and in succession, by the most eminent minds. Lord Bacon, the restorer of the physical sciences, first opened the way by remarking that the southern extremi- ties of the two worlds terminate in a point, turned to- wards the Southern Ocean, while they go on widening towards the north. After him, Reinhold Forster, the learned and judicious companion of Captain Cook in his second voyage round the world, took up this observation and developed it to a much greater extent. He points out substantially three analogies, three coincidences in the structure of the continents. The first is that the southern points of all the con- tinents are high and rocky, and seem to be the extremi- FIGURE -OF THE CONTINENTS, 37 ties of mountain belts, which come from far in the interior, and breax off abruptly, without transition, at the shore of the ocean. Thus America, which terminates in the rocky precipices of Cape Horn, the last repiesen- tatives of the already broken chain of the Andes; thus Africa, at the Cape of Good Hope, with its high plateaus and its Table Mountain, which rises from the bosom of the ocean to a height of more than 4,000 feet; thus Asia with the peninsula of the Deccan, which sends out the chain of the Ghauts to form the high rocks of Cape Comorin; Australia, lastly, whose southern extremity presents, at Cape Southeast, of Van Diemen’s Land, the same abrupt and massive nature. A second analogy is, that the continents have, east, of the southern points, a large island, or a group of islands more or less considerable. America has the Falkland Islands; Africa, Madagascar and the volcanic islands which surround it; Asia has Ceylon; and Australia, the two great islands of New Zealand. A third peculiarity of configuration, common to these same parts of the world, is a deep bend of their western “side towards the interior of the continent. On this side their flanks are as if hollowed into a vast gulf. In America, the concave summit of this inflection is in- dicated by the position of Arica, at the foot of the hign Cordillera of Bolivia. In Africa, the Gulf of Guinea expresses more strongly still this characteristic feature. It is more feebly marked in Asia by the Gulf or Cam- baye, and the Indo-Persian Sea; it reappears fully in Australia, where the Gulf of Nuyts occupies almost tha whole southern side. 4 35 COMPARATIVE PHYSICAL GEOGRAPHY. Forster did not stop here. Seeking to explain to him- self these remarkable coincidences in the structure of the great terrestrial masses, he arrived at the conclusion that they were due to a single cause, and that this cause was a great cataclysm coming from the south-west. The waters of the ocean, dashing violently agains! the barrier the continents opposed to them, ground away their sides with fury, scooped out the deep gulf open towards the south-west, swept off all the movable earth from the southern side, and left nothing standing but those rocky points, that formed only the skeleton The islands on the east would be only the accumulatec tuins of this great catastrophe, or the pieces of the conti nent protected from total destruction by the jutting poin. which received the first shock. This hypothesis, bold as it is ingenious, was admitted by several of the most distinguished contemporaries of Forster. Pallas, among others, the celebrated northern traveller, inclines to receive this general cataclysm from the south-west, which seems to him to explain the great geological phenomena he had observed in the north of Asia. He attributes to it the hollowing out of the deey gulfs which cut into the south of Europe and of Asia, and the formation of the great plains on the north, of those of Siberia, in particular. The whole ground, according to him, would be com- posed of earth torn from the. Southern countries, trans- norted by the waves of the ocean, and by them deposited wm these places, after their fury had been spent upon the Himalaya, or the great table land of Asia. It is thus that he explains the presence in Siberia of fossil ele. FI@.2E OF THE CONTINENTS. 39 phants and of mammoths, and a multitude of other animals and plants which live at the present day only under the sky of the tropics. He remarked, moreover, in support of tais hypothesis, that the disproportion ex- isting between the extent of the part of Asia situated south of the Himalaya, compared with that of the vast plains which flank the north of_the central mass of the continent, seems to indicate that a great portion of these southern regions has been carried away by this great flood. Pallas, lastly, applies the same observation to America, the western part of which is reduced to a narrow strip, while the region east of the Andes makes almost the whole of the continent. Seductive as this idea is.at the first glance, it is scarcely necessary to say that all that modern geology has taught upon the structure of the mountains, their rise, and the composition of the soil, forbid us to adopt it. It dates from a period when the mind, struck for the first time with the revolutions of the globe, of which it saw the traces everywhere, found no force sufficiently powerful to bring them about, and when water, in par- ticular, seemed the only agent that could be resorted to for their explanation. Nevertheless, it has the ‘merit of binding together, and of fixing, in a precise manner, certain great facts, the existence of which is incon- testable. At a later period Humboldt also shows that he is watching those general phenomena of the configuration of the continents, seemingly destined to reveal the secret of their formation. He first calls our attention to the singul ir paralletism existing between the two sides cart aeeymanaera, sree 40 COMPARATIVE PHYSICAL GEOGRAPHY. of tie Atlantic. The salient angles of the ene cor- respond to the reéntering angles of the other; Cape St. Roque in America, to the Gulf of Guinea; the head-iand of Africa, of which Cape Verd is the extren.e voint, td the Gulf of Mexico, so that this ocean takes the form of a great valley, like those the mountainous co-n‘vies pre- sent in such numbers. Steffens pushed the study of these analcgies of the structure of the continents further still, and the picture which he gives us of them opens several new views upon the subject. He remarks, first, that the: lands ex- pand and come together towards the north, while they separate and narrow down to points in the scxth, Now this tendency is marked, not only in the prin:ipal masses of the continents, but also in all the important, peninsulas which detach themselves from it. Greenland, Cali- fornia, Florida, in America; Scandinavia, Spain, Italy, and Greece, in Europe; the two Indies, Ccrea, Kam- tschatka, in Asia, all have their points turned towards the south. Passing to. the grouping of the continuats among themselves, this learned man brings to our view the fact that these great terrestrial masses are groped two by two, in three double worlds, of which the two component parts are united together by an isthmus, or by a chain of islands; moreover, on one side of the isthmus is found an archipelago, on the opposite side a peninsula. The purest type of this grouping of the c(ntinents is America. Its two halves, North America and South Amrica, are nearly equal in size, and simili:r in form; they form, so to speak, an equilibrium. The isthmus FIGURE OF THE CONTINENTS. Al which unites them is long and narrow. The archipelago on the east, that of he Antilles, is considerable; the peninsula on the west, California, without being greatly extended, is clearly outlined. The two other double worlds are less regular, less symmetrical. First, the component continents are of unequal size; then the two northern continents are, united, and, as it were, joined back to back. Steffens divides them by a line passing through the Caucasus, and coming out upon the Persian Gulf. He thus recom- bines with Europe a part of Western Asia and Arabia, and gives Africa for its corresponding continent. They are united by the Isthmus of Suez, the shortest and most northern of all. The peninsula found on the east is Arabia, which is of considerable size; the archipelago on the west is that of Greece, which is comparatively of small importance. This relation is evidently, gentlemen, as you will agree, a forced one. But it seems to me that it would be easy to reéstablish the analogy, so far as the irregu- larity of structure in the European continent permits, by considering Italy and Sicily, which almost touch Africa by Cape Bon, as the true isthmus. The archipelago is then found on the east, according to the rule, and the peninsula, Spain, on the west. The third double world, Asia-Australia, is more nor- mal; it approaches nearer the type. The isthmus which unites them is broken, it is true. But that long, continuous chain of islands, stretching without deviation from the peninsula of Malacca, by Sumatra, Java, and the other islands of the Sonde, to New Holland, oers A4® 42 COMPARATIVE PHYSIVA =EOGRAPHY. so striking an analogy and parallelism to tne isttuus which unites the two Americas, that, before Steffens, Ebel and Lamark had already pointed it veut. “Lhe great archipelago of Borneo, Celebes, and of the Moluc- cas, corresponds to that of the Antilles; the peninsula of India, to California. Here the disproportion between the two continents, as to their extent, is pushed to the extreme. Asia-Aus- tralia presents the union of the greatest and the sznallest of the terrestrial masses. These three double worlds exhaust the possible rominently out, by his barometrical sec- tions, the remarkable forms of the plateau of Mexico, and of the high valleys of the Andes. No one of the great physical consequences connected with this struc- ture escaped his penetrating sagacity. After him it was not allowed to neglect the important element of the altitudes, and this great truth remained an acqui- sition to science. Carl Ritter soon after applied these principles to the study of all the continents. Drawing from the treasures of his vast erudition, he availed himself of all the docu- ments scattered over thousands of volumes, to give us a true image of the structure of the continents. He distin- guished with greater precision the high plateaus of Cen- tral Asia and of Western Asia from the low lands.which surround them; he exhibited the contrast. between the high lands of Southern Africa, and the low plains of the Nile and of Sahara. Each of the countries of the Ola World under this new light appeared to our eyes for the first time in its true form, as those of the New World had been revealed by Humboldt. For a Jong time still we shall have to persevere in this path which genius has opened, in order to complete by observation the work so happily begun. But have we not another step to take? Shall we not find here, in the midst of this infinite variety of forms of relief, some of those grand analogies which have struck us in the study of the horizontal forms, some of those genera} facts which authorize us to admit for the elevations, a{so, some great common law around which the partic- ular facts arrange themselves? We shai! endeavor to solve this important question 56 COMPARATIVE PHYSICAL GEOGRAPHY. not, gentlemen, by any hypothesis, but by the combina- tion and exposition of the facts recognized in science. For this purpose I may often be obliged to quote figures ; but even figures have their eloquence. These, for greater convenience, I shall express in round numbers, as it will sufficiently answer the end I propose. The examination of the general reliefs of the great masses of dry land on the surface of the globe, leads us, in fact, to the recognition of certain great analogies, certain great laws of relief, which apply, whether to cer- tain groups of continents, or to all the continents taken together, or to the whole earth. ,I shall point out, one after another, these general facts, supporting them by examples; and, with the aid of the profiles you have before you, I hope to make clear to you the general law which appears to me to follow from them. 1. All the continents rise gradually from the shores of the seas towards the interior, to a line of highest eleva- ‘ion of the masses, and of the peaks surmounting them, to a maximum of swell. This fact appears trivial in the stating, because it seems so much according to the nature of things. But it is not so for him who knows the geologiéal history of eur continents and the revolutions their surface has undergone. The question is asked, why we should not have, in the interior of vast continents like Asia or America, some great depression, the bed of which should . be sunk below the surface of the oceans. And in fact this circumstance is not absolutely wanting to our con- tinents; we may cite, as a case of the kind, the great nollow, the hottom of which is occupied by the Caspian Sea. It is known thyt the surface of this sea, and even of RELIEF Ot THE CONTINENTS. 57 a grea‘ part of the surrounding countries, is below ‘he common level of the oceans; further, its basis presents in its southern parts considerable depths. The valley of the Jordan and Dead Sea, together with its lakes and the river, is almost entirely below the level of the Medi- terranean. The recent measurements of Bertou, of Russegger, and of several others, among whom I will mention, as the most recent of these bold explorers, an American, Lieut. Lynch, have proved that the level of the Dead Sea is about 1,300 feet below the level of the oceans, and that its depth descends at least as much more. What masks these depressions, moreover, is the water filling them, the surface of which must be considered as forming a part of that of the continents. Besides the three largest of the lakes of Canada, several of the lakes of the Italian Alps, the bed of which sinks below the level of the sea, would appear as similar excavations. We may say the same of the midland seas bordering the European continent on the north and on the south. 2. In all the continents, the line of greatest elevation in the summit of ascent is placed out of the centrs, on one of the sides, at an unequal distance from the shores of the seas. From this fact result two slopes, unequal in length and in inclination. This is analogous to what in mountains, is called the slope and the counter slape. The length of these two inclined planes estiriated approximately and in rouna numbers, is nearly «s fol- lows, in the different transverse sections of the continents represented by the profiles which we have before us (See plates m. and m1.) *S9]QD] ay] U2 soUDU AY] fo S7D272U2 DY] LV $.19}197 DY,T, ‘yaaf fo spuvsnoy] 24D UIF1LDUL 3Y] UL B4aQuInU IY], ; & : 7 [— TE | Fr : 9 | Zl Aor | Bet 91 i 8I oof | ¥ VISV NUGLSVa'I ! a) H 1 Hos | 8 t a Hn‘oe T 0d 06 | z y | i : 9 : : ; OT | ieee } * VESV Sa. “Tr tel aes i ‘VISV Nusisam ti [];. H t t i: pe ot ; : PI | a a i od ibs Ry ve | o90"08 ee : WS SESS 000% a0‘, SE ay i t Y 8 H° are ‘Nvogda-vianrma f°! | oR Vv a a 000'81 SN Tg00'st j | 119 Sy ig i oy i : ‘GdOUNT TVALNAO*A ! *VOREAV' IA} yor 91 te 9 La @ “XN we? 000'81 ooo “HLOOG ‘ULQOG OL HIYON —'ATHAM ATO *HLUON SS AKC AX a z 9 d Hs ; PI al i oy i 0Ge VOIWAINV BLINOS “AE . ; 3 Tey ; 000 9% i s or y ‘ rl A i | St of VOINSNVY WLNOS “I 2 é od 000 Ga} 9 f ol PI 61g VOTERWY IWHLNGO “I i | Ao : H a 0 91 A 000‘31 i i \ ol | ’ e 5, Gl NERA OY HLYON 'I ae 1 a ne ae Weg ae ‘ 3 } L = ‘JIL O10. “EST = “ESTA\ OL LSVY—'CTYAOM MAN ‘JIL BCL “LSV RELIEF OF THE CONTINENTS. 63 NEW WORLD. » > al Lenoru in Mites, Eastern Western Slopes. Slope. 1.— Norra America. From Washington to the Bay of St. Francisco ; culminating point, the central chain of the Recizy Mountains, .........6- 1,600 800 2.— CENTRAL America. From Porto Rico, through Mexico, to the Pa- cific Ocean—the line slightly broken to take in the Great Antilles; culminating point, the plateau of Mexico, ...... 2,000 300 i 3.—Sourn America. From the mouth of the Amazon, through the table land of Peru, to the Pacific Ocean ; culminating point, the Chimborago, . . . 1,850 1 4.—Sovura America. From the coasts of Brazil, north to Rio Janei- ro, through the Lake of Titicaca, to the Pa- cific; culminating point, the Nevado de SOPataly tyey iat esicee ee we ace arse Gre) 1,600 200 We see, by this table, that one of the general slopes of the continents is always, if we take the mean, at least four or five times as large as the other. 3. This law of increase of reliefs is common to the mass elevations, and to the linear elevations; that is, the height of the low lands and of the table lands increases at the same time with the absolute elevation of the mountains. There is a proportional gradation. This law is exhibited by the following table, con- taining the principal elements I have used in construct- ng the profiles. As they are intended to set in a clear 64 COMPARATIVE PHYSICAL GEOGR KPHY. light the most gengral features of the relief of the con- tinents, these profiles do not always follow an exactly _ straight line, but they sometimes embrace rather a transverse zone. For the same reason I merely indi- cate, without taking them ints the view, several lofty volcanic peaks, isolated like the Ararat, the Erdshish of Asia Minor, which, considered in relation to the general relief of the countries where they are found, are but accidents, and cause only a local modification. They are marked in the tables by an asterisk. The first column contains the height of the plateaus, the second that of the loftiest corresponding peaks, both in English feet. In plates 1. and m. they are both indi- cated by their initials. . OLD WORLD. — North to South. Low Ids and Highest 1. —Eastvern Asta. Table lands.| Mountains. Coast of the Frozen Ocean, mouth of the Je- TUSE Ty gs sds. soi ga) Rani dey soe eas CaN IE ASE AY 0 0 Plains of Siberia, Barnaul, foot of the Altai Mountains: