BERKELEY LIBRARY UNIVERSITY OF CALIFORNIA EARTH SCIENCES LIBRARY THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA PRESENTED BY PROF. CHARLES A. KOFOID AND MRS. PRUDENCE W. KOFOID jsr* PRINCIPLES OF GEOLOGY. VIEW OF THF, TEMPLE OF SERA.PIS AT PUZZUOLI IN 1836. V V PRINCIPLES OF GEOLOGY; OK, THE MODERN CHANGES OF THE EARTH AND ITS INHABITANTS CONSIDERED AS ILLUSTRATIVE OF GEOLOGY. BY SIR CHARLES LYELL, M.A. F.R.& VICE-PRESIDENT OF THE GEOLOGICAL SOCillETSI \1V LONDON; AUTHOR OF "A MANUAL Of ELEMENTARY GEOLOGY," "TRAVELS IN NORTH AMERICA," "A SECOND VISIT TO THE UNITED STATES," ETC. ETC. NEW AND ENTIRELY REVISED EDITION. Sllnatrafei mitjr 3#np3, 'fykiu, unit IBnutats. NEW YOKE: D. APPLETON & CO., 346 & 348 BROADWAY. * M.DCOO.L1V. " Vere scire est per causas scire." BACON. "The stony rocks are not primeval, but the daughters of Time." LINNAEUS, Syst. Nat. ed. 5, Stockholm, 1748, p. 219. " Amid all the revolutions of the globe, the economy of nature has been uniform, and her laws are the only things that have resisted the general movement. The rivers and the rocks, the seas and the continents have been changed in all their parts ; but the laws which direct those changes, and the rules to which they are subject, have remained invariably the same." PLAYFAIK, Illustrations of the Hut- tonian Theory, 374. " The inhabitants of the globe, like all the other parts of it, are subject to change. It is not only the individual that perishes, but whole species. " A change in the animal kingdom seems to be a part of the order of Nature, and is visible in instances to which human power cannot have extended." PLAYFAIR, Illustrations of the Huttonian Theory, 413. PEEFACE TO THE NINTH EDITION. THE Principles of Geology in the first five editions embraced not only a view of the modern changes of the earth and its inhabitants, as set forth in the present work, but also some account of those monuments of analogous changes of ancient date, both in the organic and inorganic world, which it is the business of the geologist to interpret. The subject last men- tioned, or " geology proper," constituted originally a fourth book, now omitted, the same having been enlarged into a sepa- rate treatise, first published in 1838, in one volume 12mo., and called " The Elements of Geology," afterwards recast in two volumes 12mo. in 1842, and again re-edited under the title of "Manual of Elementary Geology," in one volume 8vo. in 1851. The " Principles" and " Manual" thus divided, occupy, with one exception, to which I shall presently allude, very different ground. The " Principles" treat of such portions of the econ- omy of existing nature, animate and inanimate, as are illus- trative of Geology, so as to comprise an investigation of the permanent effects of causes now in action, which may serve as records to after ages of the present condition of the globe and its inhabitants. Such effects are the enduring monuments of the ever-varying state of the physical geography of the globe, the lasting signs of its destruction and renovation, and the memorials of the equally fluctuating condition of the organic world. They may be regarded, in short, as a symbolical lan- guage, in which the earth's autobiography is written. In the " Manual of Elementary Geology," on the other hand, I have treated briefly of the component materials of the earth's crust, their arrangement and relative position, and their organic contents, which, when deciphered by aid of the key supplied VI PKEFACE. by the study of the modern changes above alluded to, reveal to us the annals of a grand succession of past events a series of revolutions which the solid exterior of the globe, and its living inhabitants, have experienced in times antecedent to the creation of man. In thus separating the two works, however, I have retained in the " Principles" (book i.) the discussion of some matters which might fairly be regarded as common to both treatises ; as for example, an historical sketch of the early progress of geology, followed by a series of preliminary essays to explain the facts and arguments which lead me to believe that the forces now operating upon and beneath the earth's surface may be the same, both in kind and degree, as those which at remote epochs have worked out geological changes. (See Analysis of Contents of this work, p. ix.) If I am asked whether the " Principles" or the " Manual" should be studied first, I feel much the same difficulty in answering the question as if a student should inquire whether he ought to take up first a treatise on Chemistry, or one on Natural Philosophy, subjects sufficiently distinct, yet insepara- bly connected. On the whole, while I have endeavored to make each of the two treatises, in their present form, quite indepen- dent of the other, I would recommend the reader to study first the modern changes of the earth and its inhabitants as they are discussed in the present volume, proceeding afterwards to the classification and interpretation of the monuments of more remote ages. CHARLES LYELL. 11 Harley Street, London, May 24, 1853. Dates of the successive Editions of the "Principles" and "Elements'" (or Manual) of Geology, by the Author. Principles, 1st vol. in octavo, published in Jan. 1830. , 2d vol. do. do Jan. 1832. , 1st vol. 2d edition in octavo 1832. , 2d vol. 2d edition do Jan. 1833. , 3d vol. 1st edition do May, 1833. , New edition (called the 3d) of the whole work in 4 vols. 12mo May, 1834. , 4th edition, 4 vols. 12mo June, 1835. , 5th do. do. do Mar. 1837. Elements, 1st edition in one vol July, 1838. Principles, 6th do. 3 vols. 12mo June, 1840. Elements, 2d edition in 2 vols. 12mo , July, 1841. Principles, 7th edition in one vol. 8vo ; Feb. 1847. , 8th edition in one vol. 8vo May, 1850, Manual of Elementary Geology (or " Elements," 3d edition) in one vol. 8vo. Jan. 1851, Manual, 4th edition, one voL 8vo Jan. 1852 Principles, 9th edition, now published in one vol. 8vo. June, 1853 ANALYSIS OF THE CONTENTS OF THE PRINCIPLES OF GEOLOGY. BOOK I. (CHAPTERS I. to XIII.) HISTOEICAL SKETCH OF THE PROGRESS OF GEOLOGY, WITH A SERIES OF ESSAYS TO SHOW THAT THE MONUMENTS OF THE ANCIENT STATE OF THE EARTH AND ITS INHABITANTS, WHICH THIS SCIENCE INTERPRETS, CAN ONLY BE UNDERSTOOD BY A PREVIOUS AC- QUAINTANCE WITH TERRESTRIAL CHANGES NOW IN PROGRESS, BOTH IN THE ORGANIC) AND INORGANIC WORLDS. CHAPTEE I. Geology defined Its relation to other Sciences Page i CHAPTER II. Oriental and Egyptian Cosmogonies Doctrines of the Greeks and Komans bearing on Geology I CHAPTER III. Historical progress of Geology Arabian Writers Italian. French, German, and English geologists before the 19th century Physico- theological school .... 17 CHAPTER IV. Werner and Hutton Modern progress of the science 46 CHAPTEE V. Prepossessions in regard to the duration of past time, and other causes which have retarded the progress of Geology 61 CHAPTEE VI. Agreement of the ancient and modern course of nature considered Changes of cli- mate 73 CHAPTERS VII. VIII. Causes of vicissitudes in climate, and their connection with changes in physical geog- raphy 92, 114 CHAPTEE IX. Theory of the progressive development of organic life at successive periods consid- eredModern origin of Man 130 X CONTENTS. CHAPTER X. Supposed intensity of aqueous forces at remote periods Erratic blocks Deluges Page 153 CHAPTER XI. Supposed former intensity of the igneous forces Upheaval of land Volcanic action. 160 CHAPTER XII. Causes of the difference in texture of older and newer rocks Plutonic and Meta- morphic action 175 CHAPTER XIII. Supposed alternate periods of repose and disorder Opposite doctrine, which refers geological phenomena to an uninterrupted series of changes in the organic and in- organic world, unattended with general catastrophes, or the development of parox- ysmal forces 180 BOOK II. (CHAPTERS XIV. to XXXII.) OBSERVED CHANGES IN THE INORGANIC WORLD NOW IN PROGRESS: FIRST, THE EFFECTS OF AQUEOUS CAUSES, SUCH AS RIVERS, SPRINGS, GLACIERS, WAVES, TIDES, AND CUR- RENTS ; SECONDLY, OF IGNEOUS CAUSES, OR SUBTERRANEAN HEAT, AS EXHIBITED IN THE VOLCANO AND THE EARTHQUAKE. CHAPTER XIV. Aqueous causes Excavating and transporting power of rivers 198 * CHAPTER XV. Carrying power of river-ice Glaciers and Icebergs 219 CHAPTER XVI. Phenomena of springs , 232 CHAPTER XVII. Reproductive effects of rivers Deltas of lakes and inland seas 251 CHAPTER XVIII. Deltas of the Mississippi, Ganges, and other rivers exposed to tidal action. . . 263 CHAPTERS XIX. XX. XXI. Denuding, transporting, and depositing agency of the waves, tides, and currents Waste of sea-cliffs on the coast of England Delta of the Rhine Deposition of sediment under the influence of marine currents 290, 821, 837 CHAPTER XXII. Observed effects of igneous causes Regions of active volcanoes 344 CHAPTERS XXIII. XXIV. History of the volcanic eruptions of the district round Naples Structure of Vesu- vius Herculaneum and Pompeii 860, 375 CONTENTS. XI CHAPTER XXV. Etna Its eruptions Structure and antiquity of the cone ............. Page 398 CHAPTER XXVI. Volcanoes of Iceland, Mexico, the Canaries, and Grecian Archipelago Mud volca- noes ................................................................. 424 CHAPTER XXVII. Earthquakes and the permanent changes attending them .................. 451 CHAPTER XXVIII. Earthquake of 1783 in Calabria .......................................... 471 CHAPTER XXIX. land, and of the be Evidence of the same afforded by the Temple of Serapis near Naples . . . 493 Elevation and subsidence of dry land, and of the bed of the sea during earthquakes les . . . CHAPTER XXX. Elevation and subsidence of land in regions free from volcanoes and earthquakes Rising of land in Sweden .............................................. 519 CHAPTERS XXXI. XXXII. Causes of earthquakes and volcanoes Theory of central fluidity of the earth Chem- ical theory of volcanoes Causes of permanent upheaval and depression of land. BOOK III. (CHAPTERS XXXIII to L.) OBSERVED CHANGES OF THE ORGANIC WORLD NOW IN PROGRESS ; FIRST, NATURE AND GEOGRAPHICAL DISTRIBUTION OF SPECIES, AND THEORIES RESPECTING THEIR CREATION AND EXTINCTION ; SECONDLY, THE INFLUENCE OF ORGANIC BEINGS IN MODIFYING PHYSICAL GEOGRAPHY ; THIRDLY, THE LAWS ACCORDING TO WHICH THEY ARE IM- BEDDED IN VOLCANIC, FRESHWATER, AND MARINE DEPOSITS. CHAPTERS XXXIII. XXXIV, XXXV. XXXVI. Whether species have a real existence in nature Theory of transmutation of species Variability of species Phenomena of hybrids in animals and plants 566, 578, 591, 600 CHAPTER XXXVII. Laws which regulate the geographical distribution of species Distinct provinces of peculiar species of plants Their mode of diffusion 612 CHAPTER XXXVIII. Distinct provinces of peculiar species of animals Distribution and dispersion of quadrupeds, birds, and reptiles 629 CHAPTER XXXIX. Geographical distribution and migrations offish Of testacea Of zoophytes Of in- sects Geographical distribution and diffusion of the human race 646 CHAPTER XL. Theories respecting the original introduction of species Reciprocal influence of species on each other 665 Xll CONTENTS. CHAPTEKS XLI. XLII. Extinction of species How every extension of the range of a species alters the con- dition of many others Effect of changes of climate Page 677, 689 CHAPTEK XLIII. Creation of species Whether the loss of certain animals and plants is compensated by the introduction of new species 701 CHAPTER XLIV. Modifications in physical geography caused by organic beings 708 CHAPTEK XLV. Imbedding of organic remains in peat, blown sand, and volcanic ejections. . . 718 CHAPTER XLVI. Imbedding of the same in alluvial deposits and in caves 780 CHAPTER XLVII. Imbedding of organic remains in aqueous deposits Terrestrial plants Insects, rep- tiles, birds, quadrupeds 742 CHAPTER XL VIII. Imbedding of the remains of man and his works 758 CHAPTER XLIX. Imbedding of aquatic animals and plants, both freshwater and marine, in aqueous deposits 765 CHAPTER L. Formation of coral reefs 775 LIST OF PLATES. DIRECTIONS TO THE BINDER. FRONTISPIECE, View of the Temple of Serapis at Puzzuoli in 1886, to face titlepage. PLATE 1. Map showing the Area in Europe which has been covered by "Water since the beginning of the Eocene Period to face p. 121 2. Boulders drifted by Ice on the Shores of the St. Lawrence. . 220 8. View looking up the Val del Bove, Etna ' 408 4. View of the Val del Bove, Etna, as seen from above 404 PRINCIPLES OF GEOLOGY. BOOK I. CHAPTER I. Geology defined Compared to History Its relation to other Physical Sciences Not to V>e confounded with Cosmogony. GEOLOGY is the science which investigates the successive changes that have taken place in the organic and inorganic kingdoms of nature ; it inquires into the causes of these changes, and the influence which they have exerted in modifying the surface and external structure of our planet. By these researches into the state of the earth and its inhabitants at former periods, we acquire a more perfect knowledge of its present con- dition, and more comprehensive views concerning the laws now govern- ing its animate and inanimate productions. When we study history, we obtain a more profound insight into human nature, by instituting a com- parison between the present and former states of society. We trace the long series of events which have gradually led to the actual posture of affairs ; and by connecting effects with their causes, we aro enabled to classify and retain in the memory a multitude of complicated relations the various peculiarities of national character the different degrees of moral and intellectual refinement, and numerous other circumstances, which, without historical associations, would be uninteresting or imper- fectly understood. As the present condition of nations is the result of many antecedent changes, some extremely remote, and others recent, some gradual, others sudden and violent ; so the state of the natural world is the result of a long succession of events ; and if we would en- large our experience of the present economy of nature, we must investi- gate the effects of her operations in former epochs. We often discover with surprise, on looking back into the chronicles of nations, how the fortune of some battle has influenced the fate of millions of our contemporaries, when it has long been forgotten by the mass of the population. With this remote event we may find insepar- ably connected the geographical boundaries of a great state, the lan- guage now spoken by the inhabitants, their peculiar manners, laws, and religious opinions. But far more astonishing and unexpected are the connections brought to light, when we carry back our researches into the history of nature. The form of a coast, the configuration of the in- 2 GEOLOGY COMPARED TO HISTORY. [On. 1. terior of a country, the existence and extent of lakes, valleys, and moun- tains, can often be traced to the former prevalence of earthquakes and volcanoes in regions which have long been undisturbed. To these remote convulsions the present fertility of some districts, the sterile character of others, the elevation of land above the sea, the climate, and various pe- culiarities, may be distinctly referred. On the other hand, many distin- guishing features of the surface may often be ascribed to the operation, at a remote era, of slow and tranquil causes to the gradual deposition of sediment in a lake or in the ocean, or to the prolific increase of testa- cea and corals. To select another example, we find in certain localities subterranean deposits of coal, consisting of vegetable matter, formerly drifted into seas and lakes. These seas and lakes have since been filled up, the lands whereon the forests grew have disappeared or changed their form, the rivers and currents which floated the vegetable masses can no longer be traced, and the plants belonged to species which for ages have passed away from the surface of our planet. Yet the commercial prosperity, and numerical strength of a nation, may now be mainly dependent on the local distribution of fuel determined by that ancient state of things. Geology is intimately related to almost all the physical sciences, as history is to the moral. An historian should, if possible, be at once pro- foundly acquainted with ethics, politics, jurisprudence, the military art, theology ; in a word, with all branches of knowledge by which any in- sight into human affairs, or into the moral and intellectual nature of man, can be obtained. It would be no less desirable that a geologist should be well versed in chemistry, natural philosophy, mineralogy, zoology, comparative anatomy, botany ; in short, in every science relating to or- ganic and inorganic nature. With these accomplishments, the historian and geologist would rarely fail to draw correct and philosophical conclu- sions from the various monuments transmitted to them of former occur- rences. They would know to what combination of causes analogous effects were referable, and they would often be enabled to supply, by inference, information concerning many events unrecorded in the defect- ive archives of former ages. But as such extensive acquisitions are scarcely within the reach of any individual, it is necessary that men who have devoted their lives to different departments should unite their efforts ; and as the historian receives assistance from the antiquary, and from those who have cultivated different branches of moral and political science, so the geologist should avail himself of the aid of many natural- ists, and particularly of those who have studied the fossil remains of lost species of animals and plants. The analogy, however, of the monuments consulted in geology, and those available in histoiy, extends no farther than to one class of histor- ical monuments those which may be said to be undesignedly commem- orative of former events. The canoes, for example, and stone hatchets found in our peat bogs, afford an insight into the rude arts and manners of the earliest inhabitants of our island ; the buried coin fixes the date CH. I.] GEOLOGY DISTINCT FROM COSMOGONY. 3 of the reign of some Roman emperor ; the ancient encampment indicates the districts once occupied by invading armies, and the former method of constructing military defences ; the Egyptian mummies throw light on the art of embalming, the rites of sepulture, or the average stature of the human race in ancient Egypt. This class of memorials yields to no other in authenticity, but it constitutes a small part only of the re- sources on which the historian relies, whereas in geology it forms the only kind of evidence which is at our command. For this reason we must not expect to obtain a full and connected account of any series of events beyond the reach of history. But the testimony of geological monuments, if frequently imperfect, possesses at least the advantage of being free from all intentional misrepresentation. We may be deceived in the inferences which we draw, in the same manner as we often mistake the nature and import of phenomena observed in the daily course of na- ture ; but our liability to err is confined to the interpretation, and, if this be correct, our information is certain. It was long before the distinct nature and legitimate objects of geology were fully recognized, and it was at first confounded with many other branches of inquiry, just as the limits of history, poetry, and mythology were ill-defined in the infancy of civilization. Even in Werner's time, or at the close of the eighteenth century, geology appears to have been regarded as little other than a subordinate department of mineralogy ; and Desmarest included it under the head of Physical Geography. But the most common and serious source of confusion arose from the notion, that it was the business of geology to discover the mode in which the earth originated, or, as some imagined, to study the effects of those cos- mological causes which were employed by the Author of Nature to bring this planet out of a nascent and chaotic state into a more perfect and habitable condition. Hutton was the first who endeavored to draw a strong line of demarcation between his favorite science and cosmogony, for he declared that geology was in nowise concerned " with questions as to the origin of things." An attempt will be made in the sequel of this work to demonstrate that geology differs as widely from cosmogony, as speculations concern- ing the mode of the first creation of man differ from history. But, be- fore entering more at large on this controverted question, it will be de- sirable to trace the progress of opinion on this topic, from the earliest ages to the commencement of the present century. CHAPTER II. HISTORICAL SKETCH OF THE PROGRESS OF GEOLOGY. Oriental Cosmogony Hymns of the Vedas Institutes of Menu Doctrine of the successive destruction and renovation of the world Origin of this doctrine Common to the Egyptians Adopted by the Greeks System of Pythagoras Of Aristotle Dogmas concerning the extinction and reproduction of genera and species Strabo's theory of elevation by earthquakes Pliny Concluding Remarks on the knowledge of the Ancients. Oriental Cosmogony. THE earliest doctrines of the Indian and Egyp- tian schools of philosophy agreed in ascribing the first creation of the world to an omnipotent and infinite Being. They concurred also in rep- resenting this Being, who had existed from all eternity, as having re- peatedly destroyed and reproduced the world and all its inhabitants. In the sacred volume of the Hindoos, called the Ordinances of Menu, comprising the Indian system of duties religious and civil, we find a pre- liminary chapter treating of the Creation, in which the cosmogony is known to have been derived from earlier writings and traditions ; and principally from certain hymns of high antiquity, called the Vedas. These hymns were first put together, according to Mr. Colebrooke,* in a connected series, about thirteen centuries before the Christian era, but they appear from internal evidence to have been written at various an- tecedent periods. In them, as we learn from the researches of Profes- sor Wilson, the eminent Sanscrit scholar, two distinct philosophical sys- tems are discoverable. According to one of them, all things were origi- nally brought into existence by the sole will of a single First Cause, which existed from eternity ; according to the other, there have always existed two principles, the one material, but without form, the other spiritual and capable of compelling " inert matter to develop its sensible properties." This development of matter into "individual and visible existences" is called creation, and is assigned to a subordinate agent, or the creative faculty of the Supreme Being embodied in the person of Brahma. In the first chapter of the Ordinances of Menu above alluded to, we meet with the following passages relating to former destructions and renovations of the world : " The Being, whose powers are incomprehensible, having created me (Menu) and this universe, again" became absorbed in the supreme spirit, changing the time of energy for the hour of repose. " When that Power awakes, then has this world its full expansion ; but when he slumbers with a tranquil spirit, then the whole system fades away For while he reposes, as it were, embodied spirits * Essays on the Philosophy of the Hindoos. CH. II] INSTITUTES OF MENU. ORIENTAL COSMOGONY. 5 endowed with principles of action depart from their several acts, and the mind itself becomes inert." The absorption of all beings into the Supreme essence is then de- scribed, and the Divine soul itself is said to slumber, and to remain for a time immersed in " the first idea, or in darkness." After which the text thus proceeds (verse fifty-seven), " Thus that immutable power by waking and reposing alternately, revivifies and destroys, in eternal suc- cession, this whole assemblage of locomotive and immovable creatures." It is then declared that there has been a long succession of manwan- taras, or periods, each of the duration of many thousand ages, and " There are creations also, and destructions of worlds innumerable : the Being, supremely exalted, performs all this with as much ease as if in sport, again and again, for the sake of conferring happiness."* No part of the Eastern cosmogony, from which these extracts are made, is more interesting to the geologist than the doctrine, so fre- quently alluded to, of the reiterated submersion of the land beneath the waters of a universal ocean. In the beginning of things, we are told, the First Sole Cause " with a thought created the waters," and then moved upon their surface in the form of Brahma the creator, by whose agency the emergence of the dry land was effected, and the peopling of the earth with plants, animals, celestial creatures, and man. After- wards, as often as a general conflagration at the close of each manwan- tara had annihilated every visible and existing thing, Brahma, on awaking from his sleep, finds the whole world a shapeless ocean. Ac- cordingly, in the legendary poems called the Puranas, composed at a later date than the Vedas, the three first Avatars or descents of the Deity upon earth have for their object to recover the land from the waters. For this purpose Vishnu is made successively to assume the form of a fish, a tortoise, and a boar. Extravagant as may be some of the conceits and fictions which dis- figure these pretended revelations, we can by no means look upon them as a pure effort of the unassisted imagination, or believe them to have been composed without regard to opinions and theories founded on the observation of Nature. In astronomy, for instance, it is declared that, at the North Pole, the year was divided into a long day and night, and that their long day was the northern, and their night the southern course of the sun ; and to the inhabitants of the moon, it is said one day is equal in length to one month of mortals.f If such statements cannot be resolved into mere conjectures, we have no right to refer to- mere chance the prevailing notion that the earth and its inhabitants had formerly undergone a succession of revolutions and aqueous catastrophes interrupted by long intervals of tranquillity. Now there are two sources in which such a theory may have origi- nated. The marks of former convulsions on every part of the surface of * Institutes of Hindoo Law, or the Ordinances of Menti, from the Sanscrit, translated by Sir William Jones, 1796. f Mend, Inst. c. i. 66, and 67. 6 OEIENTAL COSMOGONY. [Cn. II. our planet are obvious and striking. The remains of marine animals imbedded in the solid strata are so abundant, that they may be expected to force themselves on the attention of every people who have made some progress in refinement ; and especially where one class of men are expressly set apart from the rest, like the ancient priesthoods of India and Egypt, for study and contemplation. If these appearances are once recognized, it seems natural that the mind should conclude in favor, not only of mighty changes in past ages, but of alternate periods of repose and disorder ; of repose, when the animals now fossil lived, grew, and multiplied of disorder, when the strata in which they were buried became transferred from the sea to the interior of continents, and were uplifted so as to form part of high mountain-chains. Those mod- ern writers, who are disposed to disparage the former intellectual advancement and civilization of Eastern nations, may concede some foundation of observed facts for the curious theories now under consid- eration, without indulging in exaggerated opinions of the progress of science ; especially as universal catastrophes of the world, and exter- minations of organic beings, in the sense in which they were understood by the Brahmins, are untenable doctrines. We know that the Egyptian priests were aware, not only that the soil beneath the plains of the Nile, but that also the hills bounding the great valley, contained marine shells ; and Herodotus inferred from these facts, that all lower Egypt, and even the high lands above Memphis, had once been covered by the sea.* As similar fossil remains occur in all parts of Asia hitherto explored, far in the interior of the continent as well as near the sea, they could hardly have escaped detection by some Eastern sages not less capable than the Greek historian of reasoning philosophically on natural phe- nomena. We also know that the rulers of Asia were engaged in very remote eras in executing great national works, such as tanks and canals, re- quiring extensive excavations. In the fourteenth century of our era (in the year 1360), the removal of soil necessary for such undertakings brought to light geological facts, which attracted the attention of a peo- ple less civilized than were many of the older nations of the East. The historian Ferishta relates that fifty thousand laborers were employed in cutting through a mound, so as to form a junction between the rivers Selima and Sutlej ; and in this mound were found the bones of ele- phants and men, some of them petrified, and some of them resembling bone. The gigantic dimensions attributed to the human bones show them to have belonged to sonie of the larger pachydermata.f But, although the Brahmins, like the priests of Egypt, may have * Herodot. Euterpe, 12. f A Persian MS. copy of the historian Ferishta, in the library of the East India ii.part iii. p. 389.) CH. II.] ORIENTAL COSMOGONY. 7 been acquainted with the existence of fossil remains in the strata, it is possible that the doctrine of successive destructions and renovations of the world, merely received corroboration from such proofs ; and that it may have been originally handed down, like the religious traditions of most nations, from a ruder state of society. The system may have had its source, in part at least, in exaggerated accounts of those dreadful catastrophes which are occasioned by particular combinations of natural causes. Floods and volcanic eruptions, the agency of water and fire, are the chief instruments of devastation on our globe. We shall point out in the sequel the extent of many of these calamities, recurring at distant intervals of time, in the present course of nature ; and shall only observe here, that they are so peculiarly calculated to inspire a lasting terror, and are so often fatal in their consequences to great multitudes of people, that it scarcely requires the passion for the marvellous, so characteristic of rude and half- civilized nations, still less the exuberant imagination of Eastern writers, to augment them into general cataclysms and conflagrations. The great flood of the Chinese, which their traditions carry back to the period of Yaou, something more than 2000 years before our era, has been identified by some persons with the universal deluge described in the Old Testament ; but according to Mr. Davis, who accompanied two of our embassies to China, and who has carefully examined their writ- ten accounts, the Chinese cataclysm is therein described as interrupting the business of agriculture, rather than as involving a general destruc- tion of the human race. The great Yu was celebrated for having " opened nine channels to draw off the waters," which " covered the low hills and bathed the foot of the highest mountains." Mr. Davis suggests that a great derangement of waters of the Yellow River, one of the largest in the world, might even now cause the flood of Yaou to be repeated, and lay the most fertile and populous plains of China under water. In modern times the bursting of the banks of an artificial canal, into which a portion of the Yellow River has been turned, has repeat- edly given rise to the most dreadful accidents, and is a source of per- petual anxiety to the government. It is easy, therefore, to imagine how much greater may have been the inundation, if this valley was ever convulsed by a violent earthquake.* Humboldt relates the interesting fact that, after the annihilation of a large part of the inhabitants of Cumana, by an earthquake in 1766, a season of extraordinary fertility ensued, in consequence of the great rains which accompanied the subterranean convulsions. " The Indians," he says, " celebrated, after the ideas of an antique superstition, by fes- tivals and dancing, the destruction of the world and the approaching epoch of its regeneration."! The existence of such rites among the rude nations of South Amer- * See Davis on " The Chinese," published by the Soc. for the Diffus. of Use. Know. vol. i. pp. 137, 147. f Humbuldt et Bonplaiid, Voy. Relat. Hist. vol. i. p. 30. 8 EGYPTIAN COSMOGONY. [CH. IL ica is most important, as showing what effects may be produced by local catastrophes, recurring at distant intervals of time, on the minds of a barbarous and uncultivated race. I shall point out in the sequel how the tradition of a deluge among the Araucanian Indians may be ex- plained, by reference to great earthquake-waves which have repeatedly rolled over part of Chili since the first recorded flood of 1590. (See chap. 29, Book II.) The legend also of the ancient Peruvians of an inundation many years before the reign of the Incas, in which only six persons were saved on a float, relates to a region which has more than once been overwhelmed by inroads of the ocean since the days of Pizar- ro. (Chap. 29, Book II.) I might refer the reader to my account of the submergence of a wide area in Cutch so lately as the year 1819, when a single tower only of the fort of Sindree appeared above the waste of waters (see Chap. 28, Book II.), if it were necessary, to prove how easily the catastrophes of modern times might give rise to traditionary narratives, among a rude people, of floods of boundless extent. Nations without written records, and who are indebted for all their knowledge of past events exclusively to oral tradition, are in the habit of confounding in one legend a series of incidents which have happened at various epochs ; nor must ,we forget that the superstitions of a savage tribe are transmitted through all the progressive stages of society, till they exert a powerful influence on the mind of the philosopher. He may find, in the monuments of former changes on the earth's surface, an apparent confirmation of tenets handed down through successive generations, from the rude hunter, whose terrified imagination drew a false picture of those awful visitations of floods and earthquakes, whereby the whole earth as known to him was simultaneously devastated. Egyptian Cosmogony. Respecting the cosmogony of the Egyptian priests, we gather much information from writers of the Grecian sects, who borrowed almost all their tenets from Egypt, and amongst others that of the former successive destruction and renovation of the world.* We learn from Plutarch, that this was the theme of one of the hymns of Orpheus, so celebrated in the fabulous ages of Greece. It was brought by him from the banks of the Nile ; and we even find in his verses, as in the Indian systems, a definite period assigned for the duration of each successive world. f The returns of great catas- trophes were determined by the period of the Annus Magnus, or great year, a cycle composed of the revolutions of the sun, moon, and planets, and terminating when these return together to the same sign whence they were supposed at some remote epoch to have set out. The duration of this great cycle was variously estimated. According to Orpheus, it was 120,000 years; according to others, 300,000; and by Cassander it was taken to be 360,000 years.t * Prichard's Egypt. Mythol. p. 177. j- Plut. de Defectu Oraculorum, cap. 12. Censorinus de Die Natali See also Richard's Egypt. Mythol. p. 182. t Prichard's Egypt. Mythol. p. 182. CH. IT.] .EGYPTIAN COSMOGONY. 9 We learn particularly from the Timseus of Plato, that the Egyptians believed the world to be subject to occasional conflagrations and deluges, whereby the gods arrested the career of human wickedness, and purified the earth from guilt. After each regeneration, mankind were in a state of virtue and happiness, from which they gradually degenerated again into vice and immorality. From this Egyptian doctrine, the poets derived the fable of the decline from the golden to the iron age. The sect of Stoics adopted most fully the system of ca- tastrophes destined at certain intervals to destroy the world. Those they taught were of two kinds; the Cataclysm, or destruction by water, which sweeps away the whole human race, and annihilates all the animal and vegetable productions of nature ; and the Ecpyrosis, or destruction by fire, which dissolves the globe itself. From the Egyp- tians also they derived the doctrine of the gradual debasement of man from a state of innocence. Towards the termination of each era, the gods could no longer bear with the wickedness of men, and a shock of the elements or a deluge overwhelmed them ; after which calamity, Astrea again descended on the earth to renew the golden age.* The connection between the doctrine of successive catastrophes and repeated deteriorations in the moral character of the human race is more intimate and natural than might at first be imagined. For, in a rude state of society, all great calamities are regarded by the people as judg- ments of God on the wickedness of man. Thus, in our own time, the priests persuaded a large part of the population of Chili, and perhaps believed themselves, that the fatal earthquake of 1822 was a sign of the wrath of Heaven for the great political revolution just then consum- mated in South America. In like manner, in the account given to Solon by the Egyptian priests, of the submersion of the island of Atlantis under the waters of the ocean, after repeated shocks of an earthquake, we find that the event happened when Jupiter had seen the moral de- pravity of the inhabitants.f Now, when the notion had once gained ground, whether from causes before suggested or not, that the earth had been destroyed by several general catastrophes, it would next be in- ferred that the human race had been as often destroyed and renovated. And since every extermination was assumed to be penal, it could only be reconciled with divine justice, by the supposition that man, at each successive creation, was regenerated in a state of purity and innocence. A very large portion of Asia, inhabited by the earliest nations, whose traditions have come down to us, has been always subject to tremen- dous earthquakes. Of the geographical boundaries of these, and their effects, I shall speak in the proper place. Egypt has, for the most part, been exempt from this scourge, and the Egyptian doctrine of great catastrophes was probably derived in part, as before hinted, from early geological observations, and in part from Eastern nations. Pythagorean Doctrines. Pythagoras, who resided for more than * Prichard's Egypt. Mythol. p. 193. f Plato's Timaeus. 10 PYTHAGOREAN SYSTEM. [Cfl. II. twenty years in Egypt, and, according to Cicero, had visited the East, and conversed with the Persian philosophers, introduced into his own country, on his return, the doctrine of the gradual deterioration of the human race from an original state of virtue and happiness ; but if we are to judge of his theory concerning the destruction and renovation of the earth from the sketch given by Ovid, we must concede it to have been far more philosophical than any known version of the cosmogonies of Oriental or Egyptian sects. Although Pythagoras is introduced by the poet as delivering his doc- trine in person, some of the illustrations are derived from natural events which happened after the death of the philosopher. But notwithstand- ing these anachronisms, we may regard the account as a true picture of the tenets of the Pythagorean school in the Augustan age ; and al- though perhaps partially modified, it must have contained the substance of the original scheme. Thus considered, it is extremely curious and instructive ; for we here find a comprehensive summary of almost all the great causes of change now in activity on the globe, and these ad- duced in confirmation of a principle of a perpetual and gradual revolu- tion inherent in the nature of our terrestrial system. These doctrines, it is true, are not directly applied to the explanation of geological pheno- mena ; or, in other words, no attempt is made to estimate what may have been in past ages, or what may hereafter be, the aggregate amount of change brought about by such never-ending fluctuations. Had this been the case, we might have been called upon to admire so extraordi- nary an anticipation with no less interest than astronomers, when they endeavor to define by what means the Samian philosopher came to the knowledge of the Copernican system. Let us now examine the celebrated passages to which we have been adverting :* " Nothing perishes in this world ; but things merely vary and change their form. To be born, means simply that a thing begins to be some- thing different from what it was before ; and dying, is ceasing to be the same thing. Yet, although nothing retains long the same image, the sum of the whole remains constant." These general propositions are then confirmed by a series of examples, all derived from natural appearances, except the first, which refers to the golden age giving place to the age of iron. The illustrations are thus consecutively ad- duced. 1. Solid land has been converted into sea. 2. Sea has been changed into land. Marine shells lie far distant from the deep, and the anchor has been found on the summit of hills. 3. Valleys have been excavated by running water, and floods have washed down hills into the sea.f * Ovid's Metamor. lib. 15. f Eluvie mons est deductus in aequor, v. 267. The meaning of this last verse is somewhat obscure ; but, taken with the context, may be supposed to allude to the abrading power of floods, torrents, and rivers. On. II] PYTHAGOREAN SYSTEM. 11 4. Marshes have become dry ground. 5. Dry lands have been changed into stagnant pools. 6. During earthquakes some springs have been closed up, and new ones have broken out. Rivers have deserted their channels, and have been re-born elsewhere, as the Erasinus in Greece, and Mysus in Asia. 7. The waters of some rivers, formerly sweet, have become bitter ; as those of the Anigris, in Greece, &c.* 8. Islands have become connected with the mainland by the growth of deltas and new deposits ; as in the case of Antissa joined to Lesbos, Pharos to Egypt, &c. 9. Peninsulas have been divided from the main land, and have be- come islands, as Leucadia ; and according to tradition, Sicily, the sea having carried away the isthmus. 10. Land has been submerged by earthquakes ; the Grecian cities of Helice and Buris, for example, are to be seen under the sea, with their walls inclined. 11. Plains have been upheaved into hills by the confined air seeking vent ; as at Trcezene in the Peloponnesus. 12. The temperature of some springs varies at different periods. The waters of others are inflammable, f 13. There are streams which have a petrifying power, and convert the substances which they touch into marble. 14. Extraordinary medicinal and deleterious effects are produced by the water of different lakes and springs. 15. Some rocks and islands, after floating and having been subject to violent movements, have at length become stationary and immovable ; as Delos and the Cyanean Isles. 16. Volcanic vents shift their position ; there was a time when Etna was not a burning mountain, and the time will come when it will cease to burn. Whether it be that some caverns become closed up by the movements of the earth, and others opened, or whether the fuel is finally exhausted, &c., &c. The various causes of change in the inanimate world having been thus enumerated, the doctrine of equivocal generation is next propounded, as illustrating a corresponding perpetual flux in the animate creation. || * The impregnation from new mineral springs, caused by earthquakes in vol- canic countries, is perhaps here alluded to. j- That is probably an allusion to the escape of inflammable gas, like that in the district of Baku, west of the Caspian ; at Pietramala, in the Tuscan Apen- nines ; and several other places. \ Many of those described seem fanciful fictions, like the virtue still so com- monly attributed to mineral waters. Raspe, in a learned and judicious essay (De Novis Insulis, cap. 19), has made it appear extremely probable that all the traditions of certain islands in the Med- iterranean having at some former time frequently shifted their positions, and at length become stationary, originated in the great change produced in their form by earthquakes and submarine eruptions, of which there have been modern ex- amples in the new islands raised in the time of history. When the series of con- vulsions ended, the island was said to become fixed. || It is not inconsistent with the Hindoo mythology to suppose that Pythagoras might have found in the East not only the system of universal ard violent catas- 12 - AEISTOTELIAN SYSTEM. [Cn. II. In the Egyptian and Eastern cosmogonies, and in the Greek version of them, no very definite meaning can, in general, be attached to the term "destruction of the world ;" for sometimes it would seem almost to imply the annihilation of our planetary system, and at others a mere revolution of the surface of the earth. Opinions of Aristotle. From the works now extant of Aristotle, and from the system of Pythagoras, as above exposed, we might certainly infer that these philosophers considered the agents of change now oper- ating in nature, as capable of bringing about in the lapse of ages a com- plete revolution ; and the Stagyrite even considers occasional catastro- phes, happening at distant intervals of time, as part of the regular and ordinary course of nature. The deluge of Deucalion, he says, affected Greece only, and principally the part called Hellas, and it arose from great inundations of rivers, during a rainy winter. But such extraordi- nary winters, he says, though after a certain period they return, do not always revisit the same places.* Censorinus quotes it as Aristotle's opinion that there were general inundations of the globe, and that they alternated with conflagrations ; and that the flood constituted the winter of the great year, or astro- nomical cycle, while the conflagration, or destruction by fire, is the summer, or period of greatest heat.f If this passage, as Lipsius sup- poses, be an amplification, by Censorinus, of what is written in " the Meteorics," it is a gross misrepresentation of the doctrine of the Stagy- rite, for the general bearing of his reasoning in that treatise tends clearly in an opposite direction. He refers to many examples of changes now constantly going on, and insists emphatically on the great results which they must produce in the lapse of ages. He instances particular cases of lakes that had dried up, and deserts that had at length become watered by rivers and fertilized. He points to the growth of the Nilotic Delta since the time of Homer, to the shallowing of the Palus Mseotis within sixty years from his own time ; and although, in the same chapter he says nothing of earthquakes, yet in others of the same treatise he shows himself not unacquainted with their effects.^ He alludes, for example, to the upheaving of one of the Eolian islands previous to a volcanic eruption. " The changes of the earth," he says, " are so slow in comparison to the duration of our lives, that they are over- looked (Xavdavsi) : and the migrations of people aftef great catastrophes, and their removal to other regions, cause the event to be forgotten." trophes and periods of repose in endless succession, but also that of periodical revolutions, effected by the continued agency of ordinary causes. For Brahma, Vishnu, and Siva, the first, second" and third persons of the Hindoo triad, severally represented the Creative, the Preserving, and the Destroying powers of the De- ity. The coexistence of these three attributes, all in simultaneous operation, might well accord with the notion of perpetual but partial alterations finally bring- ing about a complete change. But the fiction expressed in the verses before quoted from Menu of eternal vicissitudes in the vigils and slumbers of Brahma seems ac- commodated to the system of great general catastrophes followed by new creations and periods of repose. * Meteor, lib. i, cap. 12. f "De Die Nat. \ Lib. ii. cap. 14, 15, and 16. Lib. ii. cap. 14, 15, and 16. On. II.] ARISTOTELIAN SYSTEM. 13 When we consider the acquaintance displayed by Aristotle, in his various works, with the destroying and renovating powers of Nature, the introductory and concluding passages of the twelfth chapter of his " Meteorics" are certainly very remarkable. In the first sentence he says, " The distribution of land and sea in particular regions does not endure throughout all time, but it becomes sea in those parts where it was land, and again it becomes land where it was sea : and there is reason for thinking that these changes take place according to a cer- tain system, and within a certain period." The concluding observation is as follows : " As time never fails, and the universe is eternal, neither the Tanais, nor the Nile, can have flowed forever. The places where they rise were once dry, and there is a limit to their operations ; but there is none to time. So also of all other rivers ; they spring up, and they perish ; and the sea also continually deserts some lands and in- vades others. The same tracts, therefore, of the earth are not, some always sea, and others always continents, but every thing changes in the course of time." It seems, then, that the Greeks had not only derived from preced- ing nations, but had also, in some slight degree, deduced from their own observations, the theory of periodical revolutions in the inorganic world : there is, however, no ground for imagining that they contem- plated former changes in the races of animals and plants. Even the fact that marine remains were inclosed in solid rocks, although ob- served by some, and even made the groundwork of geological specu- lation, never stimulated the industry or guided the inquiries of natural- ists. It is not impossible that the theory of equivocal generation might have engendered some indifference on this subject, and that a belief in the spontaneous production of living beings from the earth or corrupt matter, might have caused the organic world to appear so unstable and fluctuating, that phenomena indicative of former changes would not awaken intense curiosity. The Egyptians, it is true, had taught, and the Stoics had repeated, that the earth had once given birth to some monstrous animals, which existed no longer ; but the prevailing opinion seems to have been, that after each great catastrophe the same species of animals were created over again. This tenet is implied in a passage of Seneca, where, speaking of a future deluge, he says, " Every animal shall be generated anew, and man free from guilt shall be given to the earth."* An old Arabian version of the doctrine of the successive revolutions of the globe, translated by Abraham Ecchellensis,f seems to form a singular exception to the general rule, for here we find the idea of dif- ferent genera and species having been created. The Gerb-mites, a sect * Omne ex intecro animal generabitur, dubiturque terrb homo inscius scelo- rum. Qusest. Nat. iii. e. 29. f This author was Rogius Professor of Syriac and Arabic at Paris, where, in 1685, he published a Latin translation of many Arabian MSS. on different de- partments of philosophy. This work has always been considered of high authority. 14: SPECULATIONS OF STRABO. [Cn. II. of astronomers who flourished some centuries before the Christian era, taught as follows : " That after every period of thirty-six thousand four hundred and twenty-five years, there were produced a pair of every species of animal, both male and female, from whom animals might be propagated and inhabit this lower world. But when a cir- culation of the heavenly orbs was completed, which is finished in that space of years, other genera and species of animals are propagated, as also of plants and other things, and the first order is destroyed, and so it goes on forever and ever."* Theory of Strabo. As we learn much of the tenets of the Egyptian and Oriental schools in the writings of the Greeks, so, many specula- tions of the early Greek authors are made known to us in the works of the Augustan and later ages. Strabo, in particular, enters largely, in the second book of his Geography, into the opinions of Eratosthenes and other Greeks on one of the most difficult problems in geology, viz., by what causes marine shells came to be plentifully buried in the earth at such great elevations and distances from the sea. He notices, amongst others, the explanation of Xanthus the Lydian, who said that the seas had once been more extensive, and that they had afterwards been partially dried up, as in his own time many lakes, rivers, and wells in Asia had failed during a season of drought. Treating this conjecture with merited disregard, Strabo passes on to the hypothesis of Strato, the natural philosopher, who had observed that the quantity of mud brought down by rivers into the Euxine was so great, that its bed must be gradually raised, while the rivers still continue to pour in an undiminished quantity of water. He, therefore, conceived that, ori- ginally, when the Euxine was an inland sea, its level had by this means become so much elevated that it burst its barrier near Byzantium, and formed a communication with the Propontis ; and this partial drainage, he supposed, had already converted the left side into marshy ground, and thus, at last, the whole would be choked up with soil. So, it was argued, the Mediterranean had once opened a passage for itself by the Columns of Hercules into the Atlantic ; and perhaps the abundance of sea-shells in Africa, near the Temple of Jupiter Ammon, might also be the deposit of some former inland sea, which had at length forced a passage and escaped. * Gerbanitse docebant singulos triginta sex mille annos quadringentos, viginti quinque bina ex singulis animalium speciebus produci, marem scilicet ac feminam ex quibus animalia propagantnr, huncque inferiorem incolunt orbem. Absolute autem coelestium orbium circulatione, quoe illo annorum conficitur spatio, iterura alia producuntur animalium genera et species, quemadmodum et plantarum alia- rumque rerum, et primus destruiur ordo, sicque in infinitumproducitur. Histor. OrienV Suppl. per Abrahamum Ecchellensem, Syrum Maronitam, cap. 7. et 8. ad calcem Chronic! Orientali. Parisiis, e Typ. Regia. 1685, fol. I have given the punctuation as in the Paris edition, there being no comma after quinque ; but, at the suggestion of M. de Schlegel, I have referred the num- ber twenty-five to the period of years, and not to the number of pairs of each species created at one time, as I had done in the two first editions. Fortis in- ferred that twenty-five new species only were created at a time ; a construction which the passage will not admit. M6m. sur 1'Hist. Nat. de 1'Italie, vol. i. p. 202. CH. II.] THEORY OF STRABO. 15 But Strabo rejects this theory, as insufficient to account for all the phenomena, and he proposes one of his own, the profoundness of which modern geologists are only beginning to appreciate. " It is not," he says, " because the lands covered by seas were originally at different altitudes, that the waters have risen, or subsided, or receded from some parts and inundated others. But the reason is, that the same land is sometimes raised up and sometimes depressed, and the sea also is simul- taneously raised and depressed, so that it either overflows or returns into its own place again. We must, therefore, ascribe the cause to the ground, either to that ground which is under the sea, or to that which becomes flooded by it, but rather to that which lies beneath the sea, for this is more movable and, on account of its humidity, can be altered with greater celerity.* It is proper," he observes in continuation, " to derive our explanations from things which are obvious, and in some measure of daily occurrence, such as deluges, earthquakes, and volcanic eruptions^ and sudden swellings of the land beneath the sea ; for the last raise up the sea also ; and when the same lands subside again, they occasion the sea to be let down. And it is not merely the small, but the large islands also, and not merely the islands, but the continents which can be lifted up together with the sea ; and both large and small tracts may subside, for habitations and cities, like Bure, Bizona, and many others, have been engulphed by earthquakes." In another place, this learned geographer, in alluding to the tradition that Sicily had been separated by a convulsion from Italy, remarks, that at present the land near the sea in those parts was rarely shaken by earthquakes, since there were now open orifices whereby fire and ignited maters, and waters escape ; but formerly, when the volcanoes of Etna, the Lipari Islands, Ischia, and others, were closed up, the imprisoned fire and wind might have produced far more vehement movements.]; The doctrine, therefore, that volcanoes are safety-valves, and that the subterranean convulsions are probably most violent when first the vol- canic energy shifts itself to a new quarter, is not modern. We learn from a passage in Strabo, that it was a dogma of the Gaulish Druids that the universe was immortal, but destined to survive catastrophes both of fire and water. That this doctrine was communi- cated to them from the East, with much of their learning, cannot be doubted. Csesar, it will be remembered, says that they made use of Greek letters in arithmetical computations.! * " Quod enim hoc attollitur aut subsidit, et vel inundat qusedam loca, vel ab iis recedit, ejus rei causa non est, quod alia aliis sola humiliora sint aut altiora ; sed quod idem solutn modi) attoliitur mod6 deprimitur, simulque etiam mod6 attollitur modo deprimitur, mare : itaque vel exundat vel in suum redit locum." Postea, p. 88. " Restat, ut causam adscribamus solo,.sive quod mari subest sive quod inundatur; potius tamen ei quod mari subest. Hoc enim multo est mobilius, et quod ob humiditatem cclerius multari possit." Strabo, Geog. Edit. Almelov. Amst. 1707, lib. 1. ^.Volcanic eruptions, eruptiones flatuum, in the Latin translations, and in the original Greek, ava^arj^am, gaseous eruptions? or inflations of land ? Ibid. p. 93. \ Strabo, lib. vi. p. 396. Book iv. || L. vi. ch. xiii. 16 KNOWLEDGE OF THE ANCIENTS. [On. IL Pliny. This philosopher had no theoretical opinions of his own con- cerning changes of the earth's surface ; and in this department, as in others, he restricted himself to the task of a compiler, without reasoning on the facts stated by him, or attempting to digest them into regular order. But his enumeration of the new islands which had been formed in the Mediterranean, and of other convulsions, shows that the ancients had not been inattentive observers of the changes which had taken place within the memory of man. Such, then, appear to have been the opinions entertained before the Christian era, concerning the past revolutions of our globe. Although no particular investigations had been made for the express purpose of interpreting the monuments of ancient changes, they were too obvious to be entirely disregarded ; and the observation of the present course of nature presented too many proofs of alterations continually in progress on the earth to allow philosophers to believe that nature was in a state of rest, or that the surface had remained, and would continue to remain unaltered. But they had never compared attentively the results of the destroying and reproductive operations of modern times with those of remote eras, nor had they ever entertained so much as a conjecture con- cerning the comparative antiquity of the human race, or of living species of animals and plants, with those belonging to former conditions of the organic world. They had studied the movements and positions of the heavenly bodies with laborious industry, and made some progress in investigating the animal, vegetable, and mineral kingdoms ; but the an- cient history of the globe was to them a sealed book, and, although written in characters of the most striking and imposing kind, they were unconscious even of its existence. CHAPTER III. HISTORY OF THE PROGRESS OF GEOLOGY Continued. Arabian writers of the tenth century Avicenna Omar Cosmogony of the Ko- ran Kazwini Early Italian writers Leonardo da Vinci Fracastoro Con- troversy as to the real nature of fossils Attributed to the Mosaic deluge Palissy Steno Scilla Quirini Boyle Lister Leibnitz Hooke's Theory of Elevation by Earthquakes Of lost species of animals Ray Physico-theo- logical writers Woodward's Diluvial Theory Burnet Whiston Vallisneri Lazzaro Moro Generelli Buffon His theory condemned by the Sorbonne as unorthodox His declaration Targioni Arduino Michell Catcott Raspe Fuchsel Fortis Testa Whitehurst Pallas Saussure. Arabian writers. AFTER the decline of the Roman empire, the cul- tivation of physical science was first revived with some success by the Saracens, about the middle of the eighth century of our era. The works of the most eminent classic writers were purchased at great ex- pense from the Christians, and translated into Arabic ; and Al Mamun, son of the famous Harun-al-Rashid, the contemporary of Charlemagne, received with marks of distinction, at his court at Bagdad, astronomers and men of learning from different countries. This ca\iph, and some of his successors, encountered much opposition and jea 1 - sy from the doc- tors of the Mahometan law, who wished the Moslems to confine their studies to the Koran, dreading the effects of the diffusion of a taste for the physical sciences.* Avicenna. Almost all the works of the early Arabian writers are lost. Amongst those of the tenth century, of which fragments are now extant, is a short treatise, " On the Formation and Classification of Minerals," by Avicenna, a physician, in whose arrangement there is con- siderable merit. The second chapter, " On the Cause of Mountains," is remarkable ; for mountains, he says, are formed, some by essential, others by accidental causes. In illustration of the essential, he instan- ces " a violent earthquake, by which land is elevated, and becomes a mountain ;" of the accidental, the principal, he says, is excavation by water, whereby cavities are produced, and adjoining lands made to stand out and form eminences.f Omar Cosmogony of the Koran. In the same century, also, Omar, surnamed " El Aalem," or " The Learned," wrote a work on " The Re- treat of the Sea." It appears that on comparing the charts of his own time with those made by the Indian and Persian astronomers two thou- sand years before, he had satisfied himself that important changes had taken place since the times of history in the form of the coasts of Asia, * Mod. Univ. Hist. vol. ii. chap. iv. section iii. f Montes quandoque fiunt ex causa essentiali, quandoque ex causa accidentali. Ex essentiali causa, ut ex vehementi motu terrae elevatur terra, et fit mons. Ac- cidentali, - fair conclusions from them. O Diluvial Theory. The theologians who now entered the field in Italy, Germany, France, and England, were innumerable ; and hence- forward, they who refused to subscribe to the position, that all marine organic remains were proofs of the Mosaic deluge, were exposed to tho imputation of disbelieving the whole of the sacred writings. Scarcely any step had been made in approximating to sound theories since the time of Fracastoro, more than a hundred years having been lost, in writing down the dogma that organized fossils were mere sports of nature. An additional period of a century and a half was now destined to be consumed in exploding the hypothesis, that organized fossils had all been buried in the solid strata by Noah's flood. Never did a theo- retical fallacy, in any branch of science, interfere more seriously with accurate observation and the systematic classification of facts. In re- cent times, we may attribute our rapid progress chiefly to the careful determination of the order of succession in mineral masses, by means of their different organic contents, and their regular superposition. But the old diluvialists were induced by their system to confound all the groups of strata together instead of discriminating, to refer all appear- ances to one cause and to one brief period, not to a variety of causes acting throughout a long succession of epochs. They saw the phenom- ena only as they desired to see them, sometimes misrepresenting facts, and at other times deducing false conclusions from correct data. Under the influence of such prejudices, three centuries were of as little avail as a few years in our own times, when we are no longer required to propel the vessel against the force of an adverse current. It may be well, therefore, to forewarn the reader, that in tracing the history of geology from the close of the seventeenth to the end of the eighteenth century, he must expect to be occupied with accounts of the retardation, as well as of the advance, of the science. It will be neces- sary to point out the frequent revival of exploded errors, and the re- lapse from sound to the most absurd opinions ; and to dwell on futile reasoning and visionary hypothesis, because some of the most extrava- gant systems were invented or controverted by men of acknowledged talent. In short, a sketch of the progress of geology is the history of a constant and violent struggle of new opinions against doctrines sanc- tioned by the implicit faith of many generations, and supposed to rest on scriptural authority. The inquiry, therefore, although highly in- teresting to one who studies the philosophy of the human mind, is too often barren of instruction to him who searches for truths in physical science. Quirini, 1676. Quirini, in 1676,* contended, in opposition to Scilla, that the diluvian waters could not have conveyed heavy bodies to the summit of mountains, since the agitation of the sea never (as Boyle had * De Testaceis fossilibus Mus. Septaliani. 26 PLOT. LISTEE. LEIBNITZ. [On. IIL demonstrated) extended to great depths ;* and still less could the tes- tacea, as some pretended, have lived in these diluvian waters ; for " the duration of the flood was brief, and the heavy rains must have destroyed the saltness of the sea /" He was the first writer who ventured to main- tain that the universality of the Mosaic cataclysm ought not to be in- sisted upon. As to the nature of petrified shells, he conceived that as earthy particles united in the sea to form the shells of mollusca, the same crystallizing process might be effected on the land ; and that, in the latter case, the germs of the animals might have been disseminated through the substance of the rocks, and afterwards developed by virtue of humidity. Visionary as was this doctrine, it gained many proselytes even amongst the more sober reasoners of Italy and Germany ; for it conceded that the position of fossil bodies could not be accounted for by the diluvial theory. Plot Lister, 1678. In the mean time, the doctrine that fossil shells had never belonged to real animals maintained its ground in England, where the agitation of the question began at a much later period. Dr. Plot, in his " Natural History of Oxfordshire" (1677), attributed to a " plastic virtue latent in the earth" the origin of fossil shells and fishes ; and Lister, to his accurate account of British shells, in 1678, added the fossil species, under the appellation of turbinated and bivalve stones. " Either," said he, " these were terriginous, or, if otherwise, the animals they so exactly represent have become extinct." This writer appears to have been the first who was aware of the continuity over large districts of the principal groups of strata in the British series, and who proposed the construction of regular geological maps.f Leibnitz, 1680. The great mathematician Leibnitz published his "Protogoea" in 1680. He imagined this planet to have been originally a burning luminous mass, which ever since its creation has been under- going refrigeration. When the outer crust had cooled down sufficiently to allow the vapors to be condensed, they fell, and formed a universal ocean, covering the loftiest mountains, and investing the whole globe. The crust, as it consolidated from a state of fusion, assumed a vesicular and cavernous structure ; and being rent in some places, allowed the water to rush into the subterranean hollows, whereby the level of the primeval ocean was lowered. The breaking in of these vast caverns is supposed to have given rise to the dislocated and deranged position of the strata " which Steno had described," and the same disruptions com- * The opinions of Boyle, alluded to by Quirini, were published a few years before, in a short article entitled " On the Bottom of the Sea." From observations collected from the divers of the pearl fishery, Boyle inferred that, when the waves were six or seven feet high above the surface of the water, there were no signs of agitation at the depth of fifteen fathoms ; and tha.t even during heavy gales of wind, the motion of the water was exceedingly diminished at the depth of twelve or fifteen feet. He had also learnt from some of his informants, that there were currents running in opposite directions at different depths. Boyle's Works, vol. iii. p. 110. London, 1744. f See Conybeare and Phillips, " Outlines of the Geology of England and Wales," p. 12. CH. Ill] HOOKE. 27 municated violent movements to the incumbent waters, whence great inundations ensued. The waters, after they had been thus agitated, deposited their sedimentary matter during intervals of quiescence, and hence the various stony and earthy strata. " We may recognize, there- fore," says Leibnitz, "a double origin of primitive masses, the one by refrigeration from igneous fusion, the other by concretion from aqueous solution."* By the repetition of similar causes (the disruption of the crust and consequent floods), alternations of new strata were produced, until at length these causes were reduced to a condition of quiescent equilibrium, and a more permanent state of things was established. f Hooke, 1688. The "Posthumous Works of Robert Hooke, M. D.," well known as a great mathematician and natural philosopher, appeared in 1705, containing "A Discourse of Earthquakes," which, we are in- formed by his editor, was written in 1668, but revised at subsequent periods.;); Hooke frequently refers to the best Italian and English authors who wrote before his time on geological subjects ; but there are no passages in his works implying that he participated in the en- larged views of Steno and Lister, or of his contemporary, Woodward, in regard to the geographical extent of certain groups of strata. His treatise, however, is the most philosophical production of that age, in regard to the causes of former changes in the organic and inorganic kingdoms of nature. " However trivial a thing," he says, " a rotten shell may appear to some, yet these monuments of nature are more certain tokens of an- tiquity than coins or medals, since the best of those may be counter- feited or made by art and design, as may also books, manuscripts, and inscriptions, as all the learned are now sufficiently satisfied has often been actually practised," &c. ; " and though it must be granted that it is very difficult to read them (the records of nature) and to raise a chronology out of them, and to state the intervals of the time wherein such or such catastrophes and mutations have happened, yet it is not impossible. " Respecting the extinction of species, Hooke was aware that the fossil ammonites, nautili, and many other shells and fossil skeletons found in England, were of different species from any then known ; but he doubted whether the species had become extinct, observing that the knowledge of naturalists of all the marine species, especially those in- habiting the deep sea, was very deficient. In some parts of his wri- * Unde jam duplex origo intelligitur primorum corporum, una, cum ab ignis fusione refrigescerent, altera, cum reconcrescerent ex solutione aquarum. f Redeunte mox simili causa strata subinde alia aliis imponerentur, et facies teneri adhuc orbis stepius novata est. Donee quiescentibus causis, atque aequili- brati?, consistentior emergeret rerum status. For an able analysis of the views of Leibnitz, in his Protogosa, see Mr. Conybeare's Report to the Brit. Assoc. on the Progress of Geological Science, 1832. \ Between the year 1688 and his death, in 1703, he read several memoirs to the Royal Society, and delivered lectures on various subjects, relating to fossil remains and the effects of earthquakes. Posth. Works, Lecture, Feb. 29, 1688. HOOKE ON EXTINCT SPECIES. [Cfl. III. tings, however, he leans to the opinion that species had been lost ; and in speculating on this subject, he even suggests that there might be some connection between the disappearance of certain kinds of animals and plants, and the changes wrought by earthquakes in former ages. Some species, he observes, with great sagacity, are "peculiar to certain places, and not to be found elsewhere. If, then, such a place had been swal- lowed up, it is not improbable but that those animate beings may have been destroyed with it ; and this may be true both of aerial and aquatic animals ; for those animated bodies, whether vegetables or animals, which were naturally nourished or refreshed by the air, would be de- stroyed by the water," &c.* Turtles, he adds, and such large ammo- nites as are found in Portland, seem to have been the productions of hotter countries ; and it is necessary to suppose that England once lay under the sea within the torrid zone ! To explain this and similar phe- nomena, he indulges in a variety of speculations concerning changes in the position of the axis of the earth's rotation, " a shifting of the earth's centre of gravity, analogous to the revolutions of the magnetic pole," &c. None of these conjectures, however, are proposed dogmatically, but rather in the hope of promoting fresh inquiries and experiments. In opposition to the prejudices of his age, we find him arguing against the idea that nature had formed fossil bodies " for no other end than to play the mimic in the mineral kingdom ;" maintaining that figured stones were " really the several bodies they represent, or the mouldings of them petrified," and not, as some have imagined, ' a lusus naturae,' sporting herself in the needless formation of useless beings, "f It was objected to Hooke, that his doctrine of the extinction of species derogated from the wisdom and power of the omnipotent Crea- tor ; but he answered, that, as individuals die, there may be some ter- mination to the duration of a species ; and his opinions, he declared, were not repugnant to Holy Writ : for the Scriptures taught that our system was degenerating, and tending to its final dissolution ; " and as, when that shall happen, all the species will be lost, why not some at one time and some at another ?" But his principal object was to account for the manner in which shells * Posth. Works, p. 327. f Posth. Works, Lecture, Feb. 15, 1688. Hooke explained with considerable clearness the different modes wherein organic substances may become lapidified ; and, among other illustrations, he mentions some silicified palm-wood brought from Africa, on which M. de la Hire had read a memoir to the Royal Academy of France (June, 1692), wherein he had pointed out, not only the tubes running the length of the trunk, but the roots at one extremity. De la Hire, says Hooke, also treated of certain trees founll petrified in the "river that passes by Bakan, in the kingdom of Ava, and which has for the space of ten leagues the virtue of petrifying wood." It is an interesting fact that the silicified wood of the Irawadi should have attracted attention more than one hundred years ago. Remarkable discoveries have been made there in later times of fossil animals and vegetables, by Mr. Crawfurd and Dr. Wallich. See Geol. Trans, vol. ii. part iii. p. 377, second series. De la Hire cites Father Duchatz, in the second volume of " Observations made in the Indies by the Jesuits." J Posth. Works, Lecture, May 29, 1689. Cu. III.] HOOKE ON EARTHQUAKES. 29 had been conveyed into the higher parts of " the Alps, Apennines, and Pyrenean hills, and the interior of continents in general." These and other appearances, he said, might have been brought about by earth- quakes, " which have turned plains into mountains, and mountains into plains, seas into land, and land into seas, made rivers where there were none before, and swallowed up others that formerly were, &c., &c. ; and which, since the creation of the world, have wrought many great changes on the superficial parts of the earth, and have been the instruments of placing shells, bones, plants, fishes, and the like, in those places where, with much astonishment, we find them."* This doctrine, it is true, had been laid down in terms almost equally explicit by Strabo, to explain the occurrence of fossil shells in the interior of continents, and to that geographer, and other writers of antiquity, Hooke frequently refers ; but the revival and development of the system was an important step in the progress of modern science. Hooke enumerated all the examples known to him of subterranean disturbance, from " the sad catastrophe of Sodom and Gomorrah," down to the Chilian earthquake of 1646. The elevating of the bottom of the sea, the sinking and submersion of the land, and most of the inequalities of the earth's surface, might, he said, be accounted for by the agency of these subterranean causes. He mentions that the coast near Naples was raised during the eruption of Monte Nuovo ; and that, in 1591, land rose in the island of St. Michael, during an eruption : and although it would be more difficult, he says, to prove, he does not doubt but that there had been as many earthquakes in the parts of the earth under the ocean, as in the parts of the dry land ; in confirmation of which, he mentions the immeasurable depth of the sea near some volcanoes. To attest the extent of simultaneous subterranean movements, he refers to an earthquake in the West Indies, in the year 1690, where the space of earth raised, or " struck upwards," by the shock, exceeded, he affirms, the length of the Alps and Pyrenees. Hooke 's diluvial Theory. As Hooke declared the favorite hypothesis of the day, " that marine fossil bodies were to be referred to Noah's flood," to be wholly untenable, he appears to have felt himself called upon to substitute a diluvial theory of his own, and thus he became in- volved in countless difficulties and contradictions. " During the great catastrophe," he said, " there might have been a changing of that part which was before dry land into sea by sinking, and of that which was sea into dry land by raising, and marine bodies might have been buried in sediment beneath the ocean, in the interval between the creation and the deluge."f Then follows a disquisition on the separation of the land from the waters, mentioned in Genesis ; during which operation some places of the shell of the earth were forced outwards, and others pressed downwards or inwards, &c. His diluvial hypothesis very much re- sembled that of Steno, and was entirely opposed to the fundamental * Posth. Works, p. 812. f Posth. Works, p. 410. 30 KAY. [Cn. IIL principles professed by him, that he would explain the former changes of the earth in a more natural manner than others had done. When, in despite of this declaration, he required a former " crisis of nature," and taught that earthquakes had become debilitated, and that the Alps, Andes, and other chains, had been lifted up in a few months, he was compelled to assume so rapid a rate of change, that his machinery ap- peared scarcely less extravagant than that of his most fanciful prede- cessors. For this reason, perhaps, his whole theory of earthquakes met with undeserved neglect. Ray, 1692. One of his contemporaries, the celebrated naturalist, Ray, participated in the same desire to explain geological phenomena by reference to causes less hypothetical than those usually resorted to.* In his essay on " Chaos and Creation," he proposed a system, agreeing in it outline, and in many of its details, with that of Hooke ; but his knowledge of natural history enabled him to elucidate the subject with various original observations. Earthquakes, he suggested, might have been the second causes employed at the creation, in separating the land from the waters, and in gathering the waters together into one place. He mentions, like Hooke, the earthquake of 1646, which had violently shaken the Andes for some hundreds of leagues, and made many alter- ations therein. In assigning a cause for the general deluge, he preferred a change in the earth's centre of gravity to the introduction of earth- quakes. Some unknown cause, he said, might have forced the sub- terranean waters outwards, as was, perhaps, indicated by "the break- ing up of the fountains of the great deep." Ray was one of the first of our writers who enlarged upon the effects of running water upon the land, and of the encroachment of the sea upon the shores. So important did he consider the agency of these causes, that he saw in them an indication of the tendency of our system to its final dissolution ; and he wondered why the earth did not proceed more rapidly towards a general submersion beneath the sea, when so much matter was carried down by rivers, or undermined in the sea- cliffs. We perceive clearly from his writings, that the gradual decline of our system, and its future consummation by fire, was held to be as necessary an article of faith by the orthodox, as was the recent origin of our planet. His discourses, like those of Hooke, are highly interesting, as attesting the familiar association in the minds of philosophers, in the age of New- ton, of questions in physics and divinity. Ray gave an unequivocal proof of the sincerity of his mind, by sacrificing his preferment in the church, rather than take an oath against the Covenanters, which he could not reconcile with his conscience: His reputation, moreover, in the scientific world placed him high above the temptation of courting popularity, by pandering to the physico-theological taste of his age. It is, therefore, * Ray's Physico-theological Discourses were of somewhat later date than Hooke's great work on earthquakea He speaks of Hooke as one " whom for his learning and deep insight into the mysteries of nature he deservedly honored." On the Deluge, chap. iv. CH. III.] WOODWAKD. BURNET. 31 curious to meet with so many citations from the Christian fathers and prophets in his essays on physical science to find him in one page pro- ceeding, by the strict rules of induction, to explain the former changes of the globe, and in the next gravely entertaining the question, whether the sun and stars, and the whole heavens, shall be annihilated, together with the earth, at the era of the grand conflagration. Woodward, 1695. Among the contemporaries of Hooke and Ray, Woodward, a professor of medicine, had acquired the most extensive information respecting the geological structure of the crust of the earth. He had examined many parts of the British strata with minute atten- tion ; and his systematic collection of specimens, bequeathed to the University of Cambridge, and still preserved there as arranged by him, shows how far he had advanced in ascertaining the order of superposi- tion. From the great number of facts collected by him, we might have expected his theoretical views to be more sound and enlarged than those of his contemporaries ; but in his anxiety to accommodate all ob- served phenomena to the scriptural account of the Creation and Deluge, he arrived at most erroneous results. He conceived " the whole terres- trial globe to have been taken to pieces and dissolved at the flood, and the strata to have settled down from this promiscuous mass as any earthy sediment from a fluid."* In corroboration of these views he insisted upon the fact, that " marine bodies are lodged in the strata according to the order of their gravity, the heavier shells in stone, the lighter in chalk, and so of the rest."f Ray immediately exposed the unfounded nature of this assertion, remarking truly that fossil bodies " are often mingled, heavy with light, in the same stratum ;" and he even went so far as to say, that Woodward " must have invented the phenomena for the sake of confirming his bold and strange hypothesis"! a strong ex- pression from the pen of a contemporary. Burnet, 1690. At the same time Burnet published his "Theory of the Earth. " The title is most characteristic of the age, " The Sacred Theory of the Earth ; containing an Account of the Original of the Earth, and of all the general Changes which it hath already undergone, or is to undergo, till the Consummation of all Things." Even Milton had scarcely ventured in his poem to indulge his imagination so freely in painting scenes of the Creation and Deluge, Paradise and Chaos. He explained why the primeval earth enjoyed a perpetual spring before the flood ! showed how the crust of the globe was fissured by " the sun's rays," so that it burst, and thus the diluvial waters were let loose from a supposed central abyss. Not satisfied with these themes, he derived from the books of the inspired writers, and even from heathen authorities, prophetic views of the future revolutions of the globe, gave a most terrific description of the general conflagration, and proved that, * Essay towards a Natural History of the Earth, 1695. Preface. f Ibid. Consequences of the Deluge, p. 165. First published in Latin between the years 1680 and 1690. 32 BURNET. WHISTON. [Cn. III. a new heaven and a new earth will rise out of a second chaos after which will follow the blessed millennium. The reader should be informed, that, according to the opinion of many respectable writers of that age, there was good scriptural ground for presuming that the garden bestowed upon our first parents was not on the earth itself, but above the clouds, in the middle region between our planet and the moon. Burnet approaches with becoming gravity the discussion of so important a topic. He was willing to concede that the geographical position of Paradise was not in Mesopotamia, yet he main- tained that it was upon the earth, and in the southern hemisphere, near the equinoctial line. Butler selected this conceit as a fair mark for his satire, when, amongst the numerous accomplishments of Hudibras, he says, " He knew the seat of Paradise, Could tell in what degree it lies; And, as he was disposed, could prove it Below the moon, or else above it." Yet the same monarch, who is said never to have slept without Butler's poem under his pillow, was so great an admirer and patron of Burnet's book, that he ordered it to be translated from the Latin into English. The style of the " Sacred Theory" was eloquent, and the book dis- played powers of invention of no ordinary stamp. It was, in fact, a fine historical romance, as Buffon afterwards declared ; but it was treated as a work of profound science in the time of its author, and was panegyrized by Addison in a Latin ode, while Steele praised it in the " Spectator." Whiston, 1696. Another production of the same school, and equally characteristic of the time, was that of Whiston, entitled, "A New Theory of the Earth ; wherein the Creation of the world in Six Days, the Universal Deluge, and the General Conflagration, as laid down in the Holy Scriptures, are shown to be perfectly agreeable to Reason and Philosophy." He was at first a follower of Burnet ; but his faith in the infallibility of that writer was shaken by the declared opinion of Newton, that there was every presumption in astronomy against any former change in the inclination of the earth's axis. This was a leading dogma in Burnet's system, though not original, for it was borrowed from an Italian, Alessandro degli Alessandri, who had suggested it in the beginning of the fifteenth century, to account for the former occu- pation of the present continents by the sea. La Place has since strength- ened the arguments of Newton, against the probability of any former revolution of this kind. The remarkable comet of 1680 was fresh in the memoiy of every one when Whiston first began his cosmological studies ; and the princi- pal novelty of his speculations consisted in attributing the deluge to the near approach to the earth of one of these erratic bodies. Having ascribed an increase of the waters to this source, he adopted Wood- CH. III.] IIUTCIIINSON. CELSIUS. SCHEUCIIZER. 33 ward's theory, supposing all stratified deposits to have resulted from the " chaotic sediment of the flood." Whiston was one of the first who ventured to propose that the text of Genesis should be interpreted dif- ferently from its ordinary acceptation, so that the doctrine of the earth having existed long previous to the creation of man might no longer be regarded as unorthodox. He had the art to throw an air of plausibility over the most improbable parts of his theory, and seemed to be pro- ceeding in the most sober manner, and, by the aid of mathematical de- monstration, to the establishment of his various propositions. Locke pronounced a panegyric on his theory, commending him for having ex- plained so many wonderful and before inexplicable things. His book, as well as Burnet's, was attacked and refuted by Keifl. * Like all who introduced purely hypothetical causes to account for natural phenom- ena, Whiston retarded the progress of truth, diverting men from the investigation of the laws of sublunary nature, and inducing them to waste time in speculations on the power of comets to drag the waters of the ocean over the land on the condensation of the vapors of their tails into water, and other matters equally edifying. Hutchinson, 1724. John Hutchinson, who had been employed by Woodward in making his collection of fossils, published afterwards, in 1724, the first part of his "Moses's Principia," wherein he ridiculed Woodward's hypothesis. He and his numerous followers were accus- tomed to declaim loudly against human learning ; and they maintained that the Hebrew Scriptures, when rightly translated, comprised a per- fect system of natural philosophy, for which reason they objected to the Newtonian theory of gravitation. Celsius. Andrea Celsius, the Swedish astronomer, published about this time his remarks on the gradual diminution and sinking of the waters in the Baltic, to which I shall have occasion to advert more par- ticularly in the sequel (ch. 29). Scheuchzer, 1708. In Germany, in the mean time, Scheuchzer pub- lished his " Complaint and Vindication of the Fishes " (1708), " Piscium Querelse et Vindicise," a work of zoological merit, in which he gave some good plates and descriptions of fossil fish. Among other conclu- sions he labored to prove that the earth had been remodelled at the deluge. Pluche, also, in 1732, wrote to the same effect; while Hoi- bach, in 1753, after considering the various attempts to refer all the an- cient formations to the flood of Noah, exposed the inadequacy of this cause. Italian Geologists Vallisneri. I return with pleasure to the geol- ogists of Italy, who preceded, as has been already shown, the natural- ists of other countries in their investigations into the ancient history of the earth, and who still maintained a decided pre-eminence. They re- futed and ridiculed the physico-theological systems of Burnet, Whiston, * An Examination of Dr. Burnet's Theory, ral hundred feet wide, and in some parts from forty to fifty feet deep. The portion of lava cut through is in no part porous or scoriaceous, but consists of a compact homogeneous mass of hard blue rock, some- what inferior in weight to ordinary basalt, and containing crystals of olivine and glassy felspar. The general declivity of this part of the bed of the Simeto is not considerable ; but, in consequence of the unequal waste of the lava, two water-falls occur at Passo Manzanelli, each about six feet in height. Here the chasm (B, fig. 16) is about forty feet deep, and only fifty broad. The sand and pebbles in the river-bed consist chiefly of a brown quartzose sandstone, derived from the upper country ; but the materials of the volcanic rock itself must have greatly assisted the attrition. This river, like the Caltabiano on the eastern side of Etna, has not yet cut down to the ancient bed of which it was dispossessed, and of which the probable position is indicated in the annexed diagram (c, fig. 16). On entering the narrow ravine where the water foams down the two cataracts, we are entirely shut out from all view of the surrounding country ; and a geologist who is accustomed to associate the character- istic features of the landscape with the relative age of certain rocks, can scarcely dissuade himself from the belief that he is contemplating a scene in some rocky gorge of a primary district. The external forms of the hard blue lava are as massive as any of the most ancient trap-rocks of Scotland. The solid surface is in some parts smoothed and almost polished by attrition, and covered in others with a white lichen, which imparts to it an air of extreme antiquity, so as greatly to heighten the delusion. But the moment we reascend the cliff the spell is broken ; for we scarcely recede a few paces, before the ravine and river disap- pear, and we stand on the black and rugged surface of a vast current of lava, which seems unbroken, and which we can trace up nearly to the distant summit of that majestic cone which Pindar called " the pillar of heaven," and which still continues to send forth a fleecy wreath of va- por, reminding us that its fires are not extinct, and that it may again give out a rocky stream, wherein other scenes like that now described may present themselves to future observers. Falls of Niagara. The falls of Niagara afford a magnificent exam- ple of the progressive excavation of a deep valley in solid rock. That river flows over a flat table-land, in a depression of which Lake Erie is situated. Where it issues from the lake, it is nearly a mile in width, and 330 feet above Lake Ontario, which is about 30 miles distant. For the first fifteen miles below Lake Erie the surrounding country, com- prising Upper Canada on the west, and the state of New York on the 216 FALLS OF NIAGARA. [Cn. XIV east, is almost on a level with its banks, and nowhere more than thirty or forty feet above them.* (See fig. 17.) The river being occasionally interspersed with low wooded islands, and having sometimes a width of three miles, glides along at first with a clear, smooth, and tranquil cur- rent, falling only fifteen feet in as many miles, and in this part of its course resembling an arm of Lake Erie. But its character is afterwards entirely changed, on approaching the Rapids, where it begins to rush and foam over a rocky and uneven limestone bottom, for the space of nearly a mile, till at length it is thrown down perpendicularly 165 feet at the Falls. Here the river is divided, into two sheets of water by an island, the largest cataract being more than a third of a mile broad, the smaller one having a breadth of six hundred feet. When the water has precipitated itself into an unfathomable pool, it rushes with great ve- locity down the sloping bottom of a narrow chasm, for a distance of seven miles. This ravine varies from 200 to 400 yards in width from cliff to cliff ; contrasting, therefore, strongly in its breadth with that of the river above. Its depth is from 200 to 300 feet, and it intersects for about seven miles the table-land before described, which terminates suddenly at Queenstown in an escarpment or long line of inland cliff facing northwards, towards Lake Ontario. The Niagara, on reaching the escarpment and issuing from the gorge, enters the flat country, which is so nearly on a level with Lake Ontario, that there is only a fall of about four feet in the seven additional miles which intervene between Queenstown and the shores of that lake. It has long been the popular belief that the Niagara once flowed in a shallow valley across the whole platform, from the present site of the Falls to the escarpment (called the Queenstown heights), where it is supposed that the cataract was first situated, and that the river has been slowly eating its way backwards through the rocks for the distance of seven miles. This hypothesis naturally suggests itself to every observer, who sees the narrowness of the gorge at its termination, and throughout its whole course, as far up as the Falls, above which point the river expands as before stated. The boundary cliffs of the ravine are usually perpendicular, and in many places undermined on one side by the impetuous stream. The uppermost rock of the table- land at the Falls consists of hard limestone (a member of the Si- lurian series), about ninety feet thick, beneath which lie soft shales of equal thickness, continually undermined by the action of the spray, which rises from the pool into which so large a body of water is pro- jected, and is driven violently by gusts of wind against the base of the * The reader will find in my Travels in North America, vol. i. ch. 2, a colored geological map and section of the Niagara district, also a bird's-eye view of the Falls and adjacent country, colored geologically, of which the first idea was sug- gested by the excellent original sketch given by Mr. Bakewell. I have referred more fully to these and to Mr. Hall's Report on the Geology of New York, as well as to the earlier writings of Hennepin and Kalm in the same work, and have speculated on the origin of the escarpment over which the Falls may have been originally precipitated. Vol. i. p. 32, and vol. ii. p. 93. CH. XIV.] FALLS OF NIAGARA. 217 precipice. In consequence of this action, and that of frost, the shale disintegrates and crumbles away, and portions of the incumbent rock overhang 40 feet, and often when unsupported tumble down, so that the Falls do not remain absolutely stationary at the same spot, even for half a century. Accounts have come down to us, from the earliest pe- riod of observation, of the frequent destruction of these rocks, and the sudden descent of huge fragments in 1818 and 1828, are said to have shaken the adjacent country like an earthquake. The earliest travel- lers, Hennepin and Kalm, who in 1678 and 1751 visited the Falls, and published views of them, attest the fact, that the rocks have been suf- fering from dilapidation for more than a century and a half, and that some slight changes, even in the scenery of the cataract have been brought about within that time. The idea, therefore, of perpetual and progressive waste is constantly present to the mind of every beholder ; and as that part of the chasm, which has been the work of the last hundred and fifty years resembles precisely, in depth, width, and char- acter, the rest of the gorge which extends seven miles below, it is most natural to infer, that the entire ravine has been hollowed out in the same manner, by the recession of the cataract. It must at least be conceded, that the river supplies an adequate cause for executing the whole task thus assigned to it, provided we grant sufficient time for its completion. As this part of the country was a wilderness till near the end of the last century, we can obtain no accurate data for estimating the exact rate at which the cataract has been receding. Mr. Bakewell, son of the eminent geologist of that name, who visited the Niagara in 1829, made the first attempt to cal- culate from the observations of one who had lived forty years at the Falls, and who had been the first settler there, that the cataract had during that period gone back about a yard annually. But after the most careful inquiries which I was able to make, during my visit to the spot in 1841-2, I came to the conclusion that the average of one foot a year would be a much more probable conjecture. In that case, it would have required thirty-five thousand years for the retreat of the Falls, from the escarpment of Queenstown to their present site. It seems "by no means improbable that such a result would be no exagger- ation of the truth, although we cannot assume that the retrograde movement has been uniform. An examination of the geological struc- ture of the district, as laid open in the ravine, shows that at every step in the process of excavation, the height of the precipice, the hardness of the materials at its base, and the quantity of fallen matter to be removed, must have varied. At some points it may have receded much faster than at present, but in general its pi ogress was probably slower, because the cataract, when it began to recede, must have had nearly twice its present height. From observations made by me in 1841, when I had the advantage of being accompanied by Mr. Hall, state geologist of New York, and in 1842, when I re-examined the Niagara district, I obtained geologi- 218 FALLS OF NIAGARA. [Cn. XIV cal evidence of the former existence of an old river-bed, which, I have no doubt, indicates the original channel through which the waters once flowed from the Falls to Queenstown, at the height of nearly three hundred feet above the bottom of the present gorge. The geological monuments alluded to, consist of patches of sand and gravel, forty feet thick, containing fluviatile shells of the genera Unio, Uyclas, Melania, &c., such as now inhabit the waters of the Niagara above the Falls. The identity of the fossil species with the recent is unquestionable, and these freshwater deposits occur at the edge of the cliffs bounding the ravine, so that they prove the former extension of an elevated shallow valley, four miles below the falls, a distinct prolongation of that now occupied by the Niagara, in the elevated region intervening between Lake Erie and the Falls. Whatever theory be framed for the hollow- ing out of the ravine further down, or for the three miles which inter- vene between the whirlpool and Queenstown, it will always be necessary to suppose the former existence of a barrier of rock, not of loose and destructible materials, such as those composing the drift in this district, somewhere immediately below the whirlpool. By that barrier the waters were held back for ages, when the fluviatile deposit, 40 feet in thickness, and 250 feet above the present channel of the river, origi- nated. If we are led by this evidence to admit that the cataract has cut back its way for four miles, we can have little hesitation in referring the excavation of the remaining three miles below to a like agency, the shape of the chasm being precisely similar. There have been many speculations respecting the future recession of the Falls, and the deluge that might be occasioned by the sudden escape of the waters of Lake Erie, if the ravine should ever be pro- longed 16 miles backwards. But a more accurate knowledge of the geological succession of the rocks, brought to light by the State Sur- vey, has satisfied every geologist that the Falls would diminish gradu- ally in height before they travelled back two miles, and in consequence of a gentle dip of the strata to the south, the massive limestone now at the top would then be at their base, and would retard, and perhaps put an effectual stop to, the excavating process. CHAPTER XV. TRANSPORTATION OF SOLID MATTER BY ICE. Carrying power of river-ice Rocks annually conveyed into the St. Lawrence by its tributaries Ground-ice ; its origin and transporting power Glaciers Theory of their downward movement Smoothed and grooved rocks The moraine unstnitified Icebergs covered with mud and stones Limits of glaciers and icebergs Their effects on the bottom when they run aground Packing of coast-ice Boulders drifted by ice on coast of Labrador Blocks moved by ice in the Baltic. THE power of running water to carry sand, gravel, and fragments of rock to considerable distances is greatly augmented in those regions where, during some part of the year, the frost is of sufficient intensity to convert the water, either at the surface or bottom of rivers, into ice. This subject may be considered under three different heads : first, the effect of surface-ice and ground-ice in enabling streams to remove gravel and stones to a distance ; secondly, the action of glaciers in the transport of boulders, and in the polishing and scratching of rocks ; thirdly, the floating off of glaciers charged with solid matter into the sea, and the drifting of icebergs and coast-ice. River-ice. Pebbles and small pieces of rock may be seen entangled in ice, and floating annually down the Tay in Scotland, as far as the mouth of that river. Similar observations might doubtless be made respecting almost all the larger rivers of England and Scotland ; but there seems reason to suspect that the principal transfer from place to place of pebbles and stones adhering to ice goes on unseen by us under water. For although the specific gravity of the compound mass may cause it to sink, it may still be very buoyant, and easily borne along by a feeble current. The ice, moreover, melts very slowly at the bottom of running streams in winter, as the water there is often nearly at the freezing point, as will be seen from what will be said in the sequel of ground-ice. As we traverse Europe in the latitudes of Great Britain, we find the winters more severe, and the rivers more regularly frozen over. M. Lariviere relates that, being at Memel on the Baltic in 1821, when the ice of the river Niemen broke up, he saw a mass of ice thirty feet long which had descended the stream, and had been thrown ashore. In the middle of it was a triangular piece of granite, about a yard in diameter, resembling in composition the red granite of Finland.* * Consid. sur les Blocs Errat. 1829. 220 TRANSPORTATION OF SOLID MATTER [Cn. XV. When rivers in the northern hemisphere flow from south to north, the ice first breaks up in the higher part of their course, and the flooded waters, bearing along large icy fragments, often arrive at parts of the stream which are still firmly frozen over. Great inundations are thus frequently occasioned by the obstructions thrown in the way of the de- scending waters, as in the case of the Mackenzie in North America, and the Irtish, Obi, Yenesei, Lena, and other rivers of Siberia. (See map, fig. 1, p. 79.) A partial stoppage of this kind lately occurred (Jan. 31, 1840) in the Vistula, about a mile and a half above the city of Dantzic, where the river, choked up by packed ice, was made to take a new course over its right bank, so that it hollowed out in a few days a deep and broad channel, many leagues in length, through a tract of sand-hills which were from 40 to 60 feet high. In Canada, where the winter's cold is intense, in a latitude corre- sponding to that of central France, several tributaries of the St. Law- rence begin to thaw in their upper course, while they remain frozen over lower down, and thus large slabs of ice are set free and thrown upon the unbroken sheet of ice below. Then begins what is called the packing of the drifted fragments ; that is to say, one slab is made to slide over another, until a vast pile is built up, and the whole being frozen together, is urged onwards by the force of the dammed up waters and drift-ice. Thus propelled, it not only forces along boulders, but breaks off from cliffs, which border the rivers, huge pieces of projecting rock. By this means several buttresses of solid masonry, which, up to the year 1836, supported a wooden bridge on the St. Maurice, which falls into the St. Lawrence, near the town of Trois Rivieres, lat. 46 20', were thrown down, and conveyed by the ice into the main river ; and instances have occurred at Montreal of wharfs and stone-buildings, from 30 to 50 feet square, having been removed in a similar manner. We learn from Captain Bayfield that anchors laid down within high-water mark, to secure vessels hauled on shore for the winter, must be cut out of the ice on the approach of spring, or they would be carried away. In 1834, the Gulnare's bower-anchor, weigh- ing half a ton, was transported some yards by the ice, and so firmly was it fixed, that the force of the moving ice broke a chain-cable suited for a 10-gun brig, and which had rode the Gulnare during the heaviest gales in the gulf. Had not this anchor been cut out of the ice, it would have been carried into deep water and lost.* The scene represented in the annexed plate (pi. 2), from a drawing by Lieutenant Bowen, R. N., will enable the reader to comprehend the incessant changes which the transport of boulders produces annually on the low islands, shores, and bed of the St. Lawrence above Quebec. The fundamental rocks at Richelieu Rapid, situated in lat. 46 K, are limestone and slate, which are seen at low- water to be covered with boulders of granite. These boulders owe their spheroidal form chiefly tc * Capt. Bayfield, Geol. Soc. Proceedings, vol. ii. p. 223. CH. XV.] BY EIVEE ICE. 221 weathering, or action of frost, which causes the surface to exfoliate in concentric plates, so that all the more prominent angles are removed. At the point a is a cavity in the mud or sand of the beach, now filled with water, which was occupied during the preceding winter (1835) by the huge erratic b, a mass of granite, 70 tons' weight, found in the spring following (1836) at a distance of several feet from its former position. Many small islands are seen on the river, such as c d, which afford still more striking proofs of the carrying and propelling power of ice. These islets are never under water, yet every winter ice is thrown upon them in such abundance, that it packs to the height of 20, and even 30 feet, bringing with it a continual supply of large stones or boulders, and carrying away others ; the greatest number being depos- ited, according to Lieutenant Bo wen, on the edge of deep water. On the island d, on the left of the accompanying view, a lighthouse is repre- sented, consisting of a square wooden building, which having no other foundation than the boulders, requires to be taken down every winter, and rebuilt on the reopening of the river. These effects of frost, which are so striking on the St. Lawrence above Quebec, are by no means displayed on a smaller scale below that city, where the gulf rises and falls with the tide. On the contrary ; it is in the estuary, between the latitudes 47 and 49, that the greatest quantity of gravel and boulders of large dimensions are carried down annually towards the sea. Here the frost is so intense, that a dense sheet of ice is formed at low water, which, on the rise of the tide, is lifted up, broken, and thrown in heaps on the extensive shoals which border the estuary. When the tide recedes, this packed ice is exposed to a temperature sometimes 30 below zero, which freezes together all the loose pieces of ice, as well as the granitic and other boulders. The whole of these are often swept away by a high tide, or when the river is swollen by the melting of the snow in Spring. One huge block of granite, 15 feet long by 10 feet both in width and height, and estimated to contain 1500 cubic feet, was conveyed in this manner to some disr tance in the year 1837, its previous position being well known, as up to that time it had been used by Captain Bayfield as a mark for the surveying station. Ground-ice. When a current of cold air passes over the surface of a lake or stream it abstracts from it a quantity of heat, and the specific gravity of the water being thereby increased, the cooled portion sinks. This circulation may continue i>ntil the whole body of fluid has been cooled down to the temperature of 40 F., after which, if the cold in- crease, the vertical movement ceases, the water which is uppermost expands and floats over the heavier fluid below, and when it has attained a temperature of 32 Fahr. it sets into a sheet of ice. It should seem therefore impossible, according to this law of congelation, that ice should ever form at the bottom of a river ; and yet such is the fact, and many speculations have been hazarded to account for so singular a phe- nomenon. M. Arago is of opinion that the mechanical action of a run- 222 GROUND-ICE AND GLACIERS. [On. XV. ning stream produces a circulation by which the entire body of water is mixed up together, and cooled alike, and the whole being thus reduced to the freezing point, ice begins to form at the bottom for two reasons, first, because there is less motion there, and secondly, because the water is in contact with. solid rock or pebbles which have a cold sur- face.* Whatever explanation we adopt, there is no doubt of the fact, that in countries where the intensity and duration of the cold is great, rivers and torrents acquire an increase of carrying power by the forma- tion of what is called ground-ice. Even in the Thames we learn from Dr. Plott that pieces of this kind of ice, having gravel frozen on to their under side, rise up from the bottom in winter, and float on the surface. In the Siberian rivers, Weitz describes large stones as having been brought up from the river's bed in the same manner, and made to float.f Glaciers. In the temperate zone, the snow lies for months in winter on the summit of every high mountain, while in the arctic regions, a long summer's day of half a year's duration is insufficient to melt the snow, even on land just raised above the level of the sea. It is there- fore not surprising, since the atmosphere becomes colder in proportion as we ascend in it, that there should be heights, even in tropical coun- tries, where the snow never melts. The lowest limit to which the per- petual snow extends downwards, from the tops of mountains at the equator, is an elevation of not less than 16,000 feet above the sea; while in the Swiss Alps, in lat. 46 N. it reaches as low as 8,500 feet above the same level, the loftier peaks of the Alpine chain being from 12,000 to 15,000 feet high. The frozen mass augmenting from year to year would add indefinitely to the altitude of alpine summits, were it not relieved by its descent through the larger and deeper valleys to regions far below the general snow-line. To these it slowly finds its way in the form of rivers of ice, called glaciers, the consolidation of which is produced by pressure, and by the congelation of water infil- tered into the porous mass, which is always undergoing partial liquefac- tion, and receiving in summer occasional showers of rain on its surface. In a day of hot sunshine, or mild rain, innumerable rills of pure and sparkling water run in icy channels along the surface of the glaciers, which in the night shrink, and come to nothing. They are often pre- cipitated in bold cascades into deep fissures in the ice, and contribute to- gether with springs to form torrents, which flow in tunnels at the bot- tom of the glaciers for many a league, and at length issue at their extremities, from beneath beautiful caverns or arches. The waters of these streams are always densely charged with the finest mud, pro- duced by the grinding of rock and sand under the weight of the mov- ing mass. (See fig. 18.) * M. Arago, Annuaire, y my guide Vampolara, but the name given in the text is the nearest to this which I find in Gemmellaro's Catalogue of Minor Cones. 400 ERUPTION OF ETNA, A. D. 1669. [On. XXV has cooled, it must become a solid wall or dike, intersecting the older rocks of which the mountain is composed ; similar rents have been observed during subsequent eruptions, as in 1832, when they ran in all directions from the centre of the volcano. It has been justly remarked by M. Elie de Beaumont, that such star-shaped fractures may indicate a slight upheaval of the whole of Etna. They may be the signs of the stretching of the mass, which may thus be raised gradually by a force from below.* The lava current of 1669, before alluded to, soon reached in its course a minor cone called Mompiliere, at the base of which it entered a sub- terranean grotto, communicating with a suite of those caverns which are so common in the lavas of Etna. Here it appears to have melted down some of the vaulted foundations of the hill, so that the whole of that cone became slightly depressed and traversed by numerous open fis- sures. Part of Catania destroyed. The lava, after overflowing fourteen towns and villages, some having a population of between three and four thousand inhabitants, arrived at length at the walls of Catania. These had been purposely raised to protect the city ; but the burning flood accumulated till it rose to the top of the rampart, which was sixty feet in height, and then it fell in a fiery cascade and overwhelmed part of the city. The wall, however, was not thrown down, but was discovered long afterwards by excavations made in the rock by the Prince of Bis- cari ; so that the traveller may now see the solid lava curling over the top of the rampart as if still in the very act of falling. This great current performed the first thirteen miles of its course in twenty days, or at the rate of 162 feet per hour, but required twenty- three days for the last two miles, giving a velocity of only twenty-two feet per hour ; and we learn from Dolomieu that the stream moved during part of its course at the rate of 1500 feet an hour, and in others it took several days to cover a few yards.f When it entered the sea it was still six hundred yards broad, and forty feet deep. It covered some territories in the environs of Catania which had never before been visited by the lavas of Etna. While moving on, its surface was in general a mass of solid rock ; and its mode of advancing, as is usual with lava streams, was by the occasional fissuring of the solid walls. A gentle- man of Catania, named Pappalardo, desiring to secure the city from the approach of the threatening torrent, went out with a party of fifty men whom he had dressed in skins to protect them from the heat, and armed with iron crows and hooks. They broke open one of the solid walls which flanked the current near Belpasso, and immediately forth issued a rivulet of melted matter which took the direction of Paterno ; but the inhabitants of that town, being alarmed for their safety, took up arms and put a stop to farther operations.^ * Mem. pour servir,