IC-NRLF * : . GEOLOGY IN 1835; A POPULAR SKETCH OF THE PROGRESS, LEADING FEATURES, AND LATEST DISCOVERIES OF THIS RISING SCIENCE. JOHN LAURANCE. fLLUSTRATED WITH DIAGRAMS AND ENGRAVINGS ON WOOD. The Isle of Cyclops, see page 118. LONDON : SIMPKIN, MARSHALL, AND CO., STATIONER'S COURT. 1835. GEOLOGY IN 1835. GEOLOGY, as the original Greek words from which the term is derived import, is the science or knowledge of the earth. Unlike Geography, which delineates the surface of the glohe, and the various trihes of animate beings with which it is peopled; and distinct from Astronomy, which defines the figure, examines the position, and has reference to the external circum- stances of our planet as a member of the solar sys- tem, the business of Geology is to investigate the internal structure and configuration of this vast mass of matter upon which we dwell a subject of the highest interest and importance to man. In the character of its results, and the magnitude and sub- limity of the objects of which it treats, Geology may be with propriety ranked in the scale of the sciences, next to Astronomy ; but while the one has attained a degree of perfection, which appears almost incompatible with the limited capacity of the human mind, the other has only, within a very recent period, assumed the dignified form of a science. It is, however, established on a secure and permanent basis : the intelligence of the age which gave it birth is fast accelerating its growth to maturity : observations are extending and facts accumu- lating, with a rapidity unparalelled in the annals of science. But no Newton has yet arisen to grapple with contending theories to concentrate with superhuman intelligence the scattered elements to mould with Promethean skill the inflexible materials, and impart perfection and immutability at once to a system. This circumstance peculiarly recommends Geology as a sub- ject of popular study. Where a high degree of excel- lence has been attained by. an individual, in any art or science, emulation the main-spring of exertion is checked : men are dissatisfied with the result of their efforts : the ardour which would have carried to the goal had the race been equal, subsides into despair. Who, in geome- try, during the long interval of two thousand years, has attempted to improve upon Euclid ? In the vain attempt to imitate the immortal productions of Greece and Rome, how many an artist has laid down his pencil in disgust ! Who has ever dared to entertain the thought of displacing Newton from the pinnacle of glory, on which he proudly stands, and bids defiance to emulation ? The mere acquisition of his ideas, the com- prehension of his complex deductions, requires an effort which ordinary minds are scarcely equal to. In Geology, however, the ground is unoccupied : a wide field is open to emulation, and results of the highest importance await a patient and attentive examination. The sphere of observation is co-extensive with the world itself, and every locality is replete with information accessible, and intelligible to all, without the preliminary acquire- ments essential to the study of Astronomy, and other abstract sciences. It is a singular feature in the history of the human mind, that while with comprehensive grasp it had mea- sured the heavens, and weighed all the planets of the solar system, and with telescopic eye was exploring the confines of the universe, the earth and all the* interest- ing phenomena which it has since disclosed, were dis- regarded. Elated by their splendid discoveries in space, Astronomers seem to have looked with contempt upon the earth beneath their feet, or at most to have regarded it merely as a station from which their observations upon surrounding objects were made, for which pur- pose a knowledge of its form and position was all that was necessary. Nothing satisfactory can be gathered from the opinions of the ancients on this interesting branch of the physical sciences. Aristotle, the master-spirit of his age, seems to have been aware that sea and land had frequently changed their relative positions : but he also contended that the earth had volition, and a better specimen of his syllogistic philosophy, which during twenty centuries held dominion over men's minds, and which at a period not very remote from our own times it was a penal offence to controvert, can scarcely be adduced " Everything which has self-motion has volition : The earth is endowed with self-motion : Ergo the earth has volition." Thales, an ancient Greek philosopher, suggested that all things had their origin in water ; and the Py- thagoreans generally seem to have had some indefinite notions on the subject of the changes which the surface B 2 of the globe had undergone from the operation of this agent. It was at a late period in modern times that specu- lations arf*|o the origin and structure of the earth were re-introduced. And as Astronomy was preceded by Astrology, so Geology was introduced by Cosmogony the early geologists being world-builders upon a most splendid scale. I shall only allude briefly to a few of these theories, the most remarkable for their whimsi- cality, as illustrative of the extraordinary vagaries into which the mind relapses in philosophical speculation, when it forsakes the plain and simple path of induction in order to make phenomena coincide with preconceived ideas. Burnet, the author of a " Sacred Theory of the Earth," (a work of great merit as a literary composition) which appeared in the sevententh century, conceived that the globe was originally invested with a light crust, which being broken up to produce the deluge, formed the mountains of its fragments. Woodward, to account for the embedding of ma- rine shells in rocky strata, imagined the principle of cohesion, which holds the particles of matter together, to have been momentarily suspended, which gave rise to the deluge, and permitted the pasty materials which it left to be penetrated with shells. The boldest idea, perhaps, was that of a philo- sopher to whom Leicestershire had the honour of giving birth William Whiston, the learned translator of Jose- phus. In his "Theory of the Earth" he creates this globe from the atmosphere of a comet, and then most unceremoniously deluges it with the tail of another : and not content with explaining these great physical events, he thought he had discovered the connection between the physical and moral world, and proposed the solution of an enigma which in all ages had puzzled theologians and divines the introduction of moral evil into the world. He argued that it was the heat retained in the earth from its origin, that inflamed the unruly passions of mankind, and impelled the whole human race to sin ! These were the principles of a man who, only a century ago, occupied the mathematical chair at Cambridge, which had been previously filled by Sir Isaac Newton ! It is true that the same restless spirit of speculation led him into heretical notions on the subject of religion, for which he was expelled and persecuted. Many philosophers, from the great Kepler down to those of recent times have imagined the earth to be possessed of vital faculties, and some have endeavoured to point out the analogy in its constitution with organ- ized beings. Demaillet, a modern French philosopher of con- siderable reputation, imagined the whole earth to have been at one period covered with water, in which all the various tribes of living beings had their origin ; even man himself, commenced his career as a fish, and had been by degrees transformed into the biped, of which he argued there were unequivocal proofs in the animals inhabiting the ocean (mermaids) , which had only un- dergone half the process of conversion, but which in time would become perfect human beings. His proofs however, required a degree of credulity which his con- temporaries were not disposed to give. Leibnitz, Descartes, and afterwards Buffon, main- B3 tained that the earth was an extinguished star, originally in a state of fusion. Buffon, however, in enlarging upon the idea, which he does most ingeniously, got into hot water with the theologians of the day. It was urged that his theory of the formation of mountains and valleys hy the subsidence of the circumfused waters, and the gradual refrigeration of the mass of the earth, was highly reprehensible, as it was contrary to the creed of the church. He was therefore required by the Sor- bonne, an inquisitorial assembly of ecclesiastics at Paris, to recant all the notions he had promulgated on the subject, and to append a declaration to the subsequent edition of his works, that he abandoned all that he had said as to the formation of the earth. But as in the case of Galileo, who under similar circumstances abjured his discovery of the motion of the earth upon its axis, the earth still continued to whirl round, so the accuracy of Buffon's conclusions was undisturbed by his recan- tation his theory is now in substance generally adopted : and the spirit of enquiry which these bigots would have suppressed, so far from invalidating, has actually thrown light upon the sacred records. To allude to all the various theories which since this period have been evulgated, would be incompatible with the object and exceed the limits of my sketch : but two eminent characters must not pass unnoticed Werner and Hutton, the champions of the rival elements fire and water. Werner asserting the supremacy of Neptune, and Hutton that of Pluto, they for a long time divided the scientific world on the comparative merits of their respective systems. They both erred in this, the too common error of immature philosophy hasty deduction from limited observation : " Each claiming truth, And truth disclaiming both," like the dogmatical asserters of the colour of the cha- meleon, they were both right to a certain extent, as we shall see hereafter that each of the causes for which they contended, have been active in the production of the terrestrial phenomena ; but both were wrong in their sweeping generalizations. Their views, moreover, were confined to the mineral structure of rocks the chemistry of the science ; modern geologists have discovered and adopted a less fallible test the organic contents, a principle which was first recognized and practically ap- plied by Smith,* in the arrangement of the strata and construction of his Geological Map of England, which has attained for him the proud appellation, ceded by universal consent of " Father of English Geologists." * At the meeting of the " British Association for the advance- ment of Science," held at Oxford in 1833, the gold medal reserved for the great luminaries emanating from this seat of education, which dazzle by their learning or benefit by their discoveries, their fellow-men, was awarded by the University, with a liberality that does it honour, to this veteran of geology, who though destitute of the advantages of education, and moving in the humble rank of a land-surveyor, by his own unaided efforts had earned the laurels, which in thfe presence and amid the plaudits of the illustrious in science from all parts of Europe, were now wreathed upon his silvery hair. A splendid instance of the reward of perseverance, and a powerful stimulus to the exertions of those to whom Nature has imparted a scientific taste, but Fortune has denied her ad- vantages. In tracing the progress of science, it is lamentable to observe the extraordinary ignorance of men whom the world have called great, as to the causes of many natural phenomena, with which we are so familiar. Voltaire, for instance, who has been all but deified by the French, to whose dwelling* pilgrimages are per- formed as to the shrine at Mecca, who presumed to arraign all the existing knowledge upon science, religion, and government, with the most perverse tenacity, insisted that fossil shells found in the earth were lusus naturce, creations of Nature in her sportive mood that oyster shells found in high situations on the Jura mountains might have been the scallops worn in the hats of pil- grims, or were probably left there by the Romans, who are known to have had a taste for oysters ; that vegetable impressions in rocky strata, were not those of real plants ; and that the bones of a rein-deer and hippopotamus found in his time near Etampes, proved merely that some lover of curiosities had once preserved them in his cabinet ! Geology, as at present understood, may be said to be a species of history the physical history of the great globe we inhabit a sort of antiquarianism which takes cognizance not of ancient coins, broken columns, and antique inscriptions in order to determine the periods and circumstances of revolutions and remarkable eras in human affairs, but investigates the great physical revolutions which our planet has undergone events of which it finds indelible records, immutable archives, the most infallible testimony, in the monuments and * Femey, near Geneva. relics of former times preserved in the mineral masses of which its exterior is composed. An inquiry which starts where human records begin to be obscure, and carries back the imagination through successive eras, to a point in the infinity of the past which the mind can scarcely contemplate a period coeval with the origin of the earth. It exhibits the surface of the earth as having been subject to a series of extraordinary and violent changes of sudden and mighty revolutions. It details " the war of elements and wreck of matter," the suc- cessive destruction and reproduction of this fair scene of man's abode, and innumerable races of animals, ere he, the self-styled " lord of creation" had assumed dominion upon the earth. As in the history of nations, we observe a gradual developement of the human faculties a pro- gressive emergence from barbarism, in which most civil- ized nations have had their origin, to that intelligence which afterwards distinguished them, so in Geology, we discover a remarkable succession in organized beings an apparent gradation from animals of a simple to those of a complex structure, and by ascending the series we arrive at a period anterior to the existence of life upon the earth when it "was without form and void, and darkness rested upon the face of the deep." The earth itself, like society or an individual, appears to have passed from infancy to adolescence, from adolescence to ma- turity, from maturity to old age, which her present feeble energies, compared with her pristine vigour, seem to indicate. The key to this long-concealed volume of nature, and to all its mystic revelations, is the extraneous fossil, {as it is termed,) the organic remains embedded in the 10 solid framework of the globe. By means of these, we are enabled to arrange the apparently innumerable strata into certain orders and classes, and assign to each a definite epoch, or period of formation; and hence establish the extraordinary fact that there is throughout these mineral masses an invariable order of superposition, which in the numberless derangements and convulsions which have shaken the earth to its centre, has never been inverted : that this order of superposition is not confined to this or that locality, but is essentially the same in the old world and the new, from the arctic to the antarctic circle ; as far at least as observations have at present extended. The discoveries of Geology, like those of Astronomy, are completely at variance with our preconceived ideas, and in some cases opposed to the evidence of the senses. Until it was proved by demonstration, it was incon- cievable, that the sun which rose and set and appeared constantly in motion, actually stood still : so the mind is indisposed to believe that the solid earth on which we tread, on which innumerable generations of men have lived and died, and our cities have stood from the earliest times, has been by turns, perhaps, the bed of a sea, the bottom of a lake, or matter ejected from beneath by vol- canic agency. At one period buried beneath the dark abyss of the ocean, at another smiling with verdure on its shores the abode now of sterility now of fertility - now of marine and now of terrestrial animals and plants. Yet even so is it with almost every portion of what we now call terra firma, which is, in fact, one vast sepulchre of animated beings ! The highest mountains have not escap- ed the general fate the " everlasting hills" can no longer with propriety be cited as the emblem of immutability. 11 1 What, short of actual demonstration, would con- vince us that the tops of the highest mountains in Eng- land once formed the bed of the sea? and that strata now buried hundreds of yards beneath the surface were once elevated above its waters ? But we have unquestionable evidence of this mighty bouleversement records as clear as any that Herculaneum and Pompeii can exhibit of their former condition. The insignificant little specimen, of which the engraving (1) in the margin is a representa- tion, is a fossil shell, (once an inhabitant of the ocean) from the top of Snowdon, the highest mountain in Wales, broken with my own hands from myriads of others in the mass of limestone * which caps its summit. The other 2 engraving (2) represents a speci- men of the vegetable productions which adorned the hills of the pri- meval world (perhaps subsequent- ly to the upheaving of the ocean de- posit of which the specimen just de- scribed is a relic) disentombed from the bowels of the earth at a depth of one thousand feet beneath its sur- face in this County ! f Now the evidence in this case is * The occurrence of this limestone on the apex, the extreme point of this mountain, while its mass is composed of older rocks destitute of organic remains, is a remarkable feature in the Geology of Wales. f Leicestershire. *From the Ashby-de-la-Zouch coal-field. 12 irresistible, it amounts to demonstration, that the ocean covered the spot where the shell was found, and remained there during a long period of time, for the limestone is formed almost entirely of shelly fragments ; and that vege- tation with all its conditions, light and heat, soil and at- mosphere, once existed where the fragile plant was pre- served. It could not have been transported thither, for its delicate texture would have been injured in the removal, whereas its fibres are as nicely preserved as if the plant had been carefully enclosed between the leaves of a book. Not only are some of the facts opposed to all ex- perience and previously-acquired ideas, as we have seen, but Geology also involves an apparent contradiction of terms for the lowest in the series sometimes occupy the highest level, and vice versa. Thus on the continent of Europe, the lowest bed, the primitive granite, on which all the other rocky masses repose, rarely makes its appearan ce except on the summits of the highest moun- tains, such as Mont Blanc and the Jung Frau, and the loftier Alps, which " Pinnacle in clouds" " Their snowy scalps" presenting in these cases, not horizontal beds, as their position at the base of the whole superstructure of strati- fied rocks might lead us to infer, but sometimes cones of vertical strata of inconceivable height, which tower in ma- jestic grandeur far above the reach of human footsteps, " As if to shew" " How earth may rise to heaven, yet leave vain man below." Such are some of the anomalies to be encountered in the study of Geology. 13 It is the uniformity of superposition, the invariable order of succession, sometimes disturbed but never in- verted, on which Geology depends as a practical science: the identity of a rock being proved by the fossils it contains, its position in the series is at once ascertained, and by a never-failing analogy, the position of other rocks is accurately inferred. It is a knowledge of these facts which guides the skilful miner in his ex- pensive operations, and it is in defiance or ignorance of them, that the many abortive searches for coal have been conceived and prosecuted at so great a sacrifice of the national wealth. The often-cited case of Bexhill, near London, in which eighty thousands pounds are said to have been expended in a fruitless search for coal, which the merest tyro in Geology would in the present day have condemned, is of itself sufficient to prove the immense advantage of Geology as a practical science. It is unnecessary to dilate upon the inestimable ad- vantages, we derive from the skill of the miner. It would be no difficult task to prove that our mineral resources are the main-spring of our national prosperity, and one of the chief causes of that proud pre-eminence which this country occupies in the scale of nations ; supplying us on the one hand with coal, the vital principle of manu- factures, on the other with iron, the raw material of the most considerable portion of our national industry the basis of so much ingenuity, the source of incalculable wealth : and how great is the aid which the science of Geology has afforded to the miner : how it has system- atized his operations how it has extended and is daily enlarging his dominion, they only who are practically 14 interested in the subject, and have watched the progress of the art of mining, can form an adequate estimate. A most gratifying instance of the successful result of an enterprize, based upon geological deductions, has lately occurred in the north of England, at the Monk- wearmouth colliery. The works in this case were com- menced on the line of the Magnesian limestone, which, as all who are acquainted with the outlines of English Geology are aware, overlies on its eastern edge, the great northern coal-formation, throughout its whole extent from the Trent to the Tyne. The coal had never been worked * in this situation, and there was nothing on the surface to indicate its existence beneath, as there usually is in coal- fields : but assured of its presence by the well-known fact that the general dip, or downward inclination of the strata was in this direction, the spirited proprietors, (Messrs. Pemberton and Thompson,) relying upon the infallible order of succession which I have just des- cribed, resolved, whatever might be the cost, to reach it. At the depth of three hundred and fifty feet they first found traces of the existence of coal, but many hundred feet of strata were subsequently passed through, and no workable seam of coal discovered. Still convinced, however, of the accuracy of the conclusions which had led them to embark in the undertaking, guided in fact by the light of science, they pursued their object with un- daunted perseverance, and at the depth of one thousand six hundred feet from the surface, or one thousand five hundred and thirteen feet below the level of the ad- jacent ocean, a depth far greater than had ever before been * Getting the coals is termed by miners working them. 15 reached in sinking for coal,* after many years of toil and anxiety, and the outlay of an enormous sum of money, they met with the reward of their efforts in a valuable bed of coal ! The identity of this bed being proved, the * The following statement of the comparative depth of some of the principal mines in the world, and of the magnitude of mining operations, may not be uninteresting : DEPTH OF MINES. FEET. Kits piihl Copper mine, in the Tyrol mountains . . . 2764 Sampson mine, at Andreasberg, in the Harz 2230 Valeuciano mine, Guanaxuato, Mexico 1770 Pearce's shaft, Consolidated mines, Cornwall 1650 Monkwearmouth Colliery, Durham 1600 Sheal Abraham mine, Cornwall 1452 Dolcoath mine, Cornwall 1410 Ecton mine, Staffordshire 1380 The deep mines in the Tyrol, the Harz, and the Andes, above described, are all in high situations ; the bottom of the Mexi- can mine, for instance, is 6000 feet higher than the top of the Cornwall shafts. The deepest perforation beneath the level of the sea, consequently the nearest approach to the earth's centre, has been made at the Monkwearinouth Colliery, above described. Pearce's shaft, Cornwall, (1338 feet below the level of the sea), was until lately, the deepest in the world ; the superiority of depth how- ever must now be ceded to Monkwearmouth, which is 1513 feet below the surface of the German Ocean. The Consolidated mines in Cornwall, have 95 shafts, or verti- cal pits, 25 miles in length. There are also four steam engines, with cylinders 90 inches in diameter ; and it is calculated that if horse-power were used, as formerly, to drain the mines, 55,000 horses would be required for this purpose in Cornwall alone. The Valenciano mine, in Mexico (1770 feet deep), has a ver- tical shaft of an octagonal form, 30 feet in diameter, walled throughout with beautiful masonry, the cost of the construction of which, was 220,000! The annual produce of the mine is 600,000, and 3000 persons are cou.itantly employed. c 2 16 existence of others beneath is inferred with so much con- fidence, that the works will be continued until the " Hut- ton" or most valuable seam in that district is reached. * This instance will illustrate the importance of the deter- minate order of succession which Geology has disclosed. Thus, the beautiful surface of this favoured island, here raised into hills, there furrowed into valleys here broken into craggy steeps, there expanding into fertile plains, which presents to the inexperienced eye an hete- rogeneous mass of earthy matter confusedly mixed to- gether, the geologist discovers to be composed of a series of distinct and well-defined mineral masses, each possessing, not only a peculiar character, but a certain geographical distribution ; so that had the conductors of the project above described, made a similar per- foration in the strata of the eastern or southern part of the island, disappointment instead of success would have been the result of their exertions ; in fact, they might in such situations, have bored through the earth's centre to the antipodes, before they met with the object of their search. It is a singular fact, and one highly favourable to the study of Geology in this country, that our island presents us with an epitome, if it may be so termed, of the greater part of the regular solid strata which com- pose the crust of the globe a model in miniature, nicely arranged and accurately defined, of the rocky * The northern coal-field, from which London draws its im- mense supplies of fuel, is known to be rapidly approaching to ex- haustion. The success of this experiment will in all probability add several centuries to the lease by which it has so long held the London market. 17 masses, which in other countries spread over a large sur- face, or are raised into lofty chains of mountains. Thus, commencing at the eastern coast, at the German ocean, in Essex, and traversing England in a north-westerly direction, we pass over the whole series, from what are regarded as the most recent, to the most ancient deposi- tions, and, with few exceptions, find each in the place assigned to it in the order of succession, corresponding with the order in which they are piled upon each other in the continent of Europe. One or two beds, the mus- chelkalk and the rothe-lwyende of the Germans, which in the north of Germany are considerable formations interposed between our new red sandstone and the coal- formation, were generally supposed to be absent in this country ; but Professor Sedgwick has lately discovered their corresponding types in the English series, so that the analogy is now complete. These various beds, as I have before stated, are identified by means of the organic fossils peculiar to each, and by the aid of these, geolo- gists have arranged them into groups, having reference to the epochs of their formation a sort of Zodiacal system, which enables us to measure, as it were, the lapse of ages, and to fix upon determinate points in the im- mensity of time which our inquiries involve, as those celebrated signs aid the astronomer, in determining the position of the innumerable stars which glitter in the vast expanse of the heavens. In the arrangement at present adopted, it is cus- tomary to class all the phenomena of stratified and un- stratified rocks, into four grand divisions, which com- prise all the minor subdivisions ; and the terms adopted are supposed to express something like the relative ages c3 18 of each. These generic terms are the primitive, transi- tion, secondary, and tertiary, and it is usual to commence with the primitive or most ancient rocks, and comedown to the most recent, as historians begin with remote, and come down to contemporary times. I shall invert the process, going back in the series from the newest to the oldest from contemporaneous to remote periods and shall only make use of the terms where they are essential in fixing the brief outlines of my sketch. But before we examine the older strata, the strati- fied masses comprised in the arrangements above ad- verted to, which contain, as it were, the records of re- mote periods, we must examine the changes now taking place on the earth's surface, the events of what may be termed the contemporaneous period changes which have affected the destiny of man the effect of causes now in operation. These are the action of rivers, and their deposits ; the destructive and reproducing effects of the ocean ; the amazing agency of volcanos and earthquakes ; the accumulation of peat-bogs, and the growth of coral reefs ; to the incessant and long-continued action of which causes, Mr. Lyell refers all the changes which the earth's surface has experienced a theory which it is the special object of his three interesting volumes to prove.* None of these changes can be appreciated in this part of the world, where all the disturbing forces are quiet, earthquakes rare events, and volcanic agency unknown ; and where the physical features of the coun- * The undue attachment to a favorite theory which pervades these volumes greatly impairs their value and general interest. 19 try are on so small a scale. It is in the great continents, the seat of active volcanos, that their effects are sensibly felt. Thus the great river Mississippi, in America, has frequently filled up its bed, and furrowed out channels in a new direction, and is fast filling up the Gulph of Mexico with the prodigious amount of solid matter brought down in its course. Enormous masses of tim- ber and vegetable matter, swept by the flood from the primeval forests of that vast country, sometimes block up the channel of its tributary streams, as in the Red river, where a raft, or an accumulation of timber and vegetable matter, is formed, twenty miles in length, of great width, and many feet in thickness : in other places the torrent is undermining its banks, while lakes and islands are forming at its aestuary. As with the Missis- sippi, so with other large rivers the Ganges, the Indus, the Niger, the Nile, and the European rivers. Such is the vast accumulation of matter at the efflux of the Niger to the Atlantic, that its course has been with difficulty as- certained ; this mighty stream, in fact, is buried in its own sands, which have stolen from the Atlantic a space equal to the whole surface of England. In Europe, upon a smaller scale, there are the delta * of the Rhone in the Mediterranean, where a considerable tract of land has gained upon the sea,f and the flat land at the mouth * At the efflux of a river into the ocean its volume expands and its banks spread out angularly in the form of the Greek letter A ; hence the origin of the term delta. f A large extent of the delta of the Rhone is known to have accumulated since the time of the Romans, and to have assumed the form of solid rock even within a later period ; inasmuch as a 20 of the Rhine the whole country of Holland in fact which has been raised from the German ocean, by the accumulation of matter brought down by this mighty stream.* On the other hand, however, the sea, re- senting this encroachment, has exhibited manifest symp- toms of reaction; and at " one fell swoop" it reclaimed fifty thousand acres ! forming that large inland bay upon which Amsterdam is built the Zuider Zee ; and it requires all the industry of the Dutch to prevent the camion imbedded hi a crystalline limestone rock has been taken from the bed of that river. Sir Richard Phillips states in his " Million of Facts" that to consolidate a soft substance into a hard rock requires at least 4000 years ! If his " Facts" had been more select, and less numerous, his work would not have been the less valuable. * An idea may be formed, of the geological effect of rivers ? from the experiments of Mr. Homer, upon the waters of the Rhine, detailed in a recent communication to the Geological Society. From these experiments, which were conducted with great care, it appears that earthy matter constitutes from one-twelfth to one- twentieth (varying with the season,) of the whole bulk of the water of this celebrated river. At Bonn, where the observations were made, the width of the river is twelve hundred feet, the mean depth fifteen feet, and the mean velocity of the current two and a half miles per hour: the average quantity of earthy matter held in suspension in the water having been ascertained to be twenty-eight grains in the cubic foot, the extraordinary result is obtained, that one hundred and forty-five thousand nine hundred aud eighty-one cubic feet of solid matter is borne past Bonn every twenty- four hours, on its voyage from the Alps to the German ocean. No wonder that the Rhine should lose its identity as it approaches the termination of its course, and that it should contract into the di- mensions of an ordinary canal. But the Rhine at Bonn, is a pel- lucid stream, compared with the Rhone at Lyons, in the summer season. 21 recurrence of similar depredations. As if to assert its supremacy, its ordinary tides now rise above the level of the country, and its infuriated billows continually menace with destruction the floodgates and barriers op- posed to their progress. Every river, and every aestuary, present us with similar phenomena, and the aggregation of matter thus formed, and forming, is generally termed allu- vium, in contradistinction to diluvium, which is ap- plied to the effects supposed to have resulted from the deluge. The flat land on each side of the river Forth, in Scotland, is an instance where the currents and tides have combined, by their reciprocal action, to form allu- vial beds. In the gravel and other matter thus thrown up, vestiges of the causes by which they were produced of course are found ; on the one hand wrecks of the ocean, on the other ruins of the land are simultaneously gathered together in the same heap ; thus in the alluvial gravel alluded to, the skeleton of an enormous whale has been discovered, and other relics of the ocean, inter- mixed with the rocky fragments brought down from the neighbouring mountains. But the changes in the earth's surface produced by the action of rivers, are exceedingly slow, and in magni- tude insignificant, compared with those which it is more particularly the business of Geology to investigate. Thus the Nile, a river of which we have the earliest and most authentic records, although its stream, densely charged with solid matter, annually overflows the plains of Egypt, has only raised the level of the surface which it inundates, six feet four inches since the com- mencement of the Christian aera, and the accumulation 22 of soil at its junction with the Mediterranean, has en- croached upon the sea, only to the extent of half a mile, since the time of Herodotus. The ocean is known, from its effects upon our coasts, to be gradually enlarging its dominion in some places and retreating from the land in others, demolishing on one side the rocky bulwarks of our island, on the other, raising sandy ramparts on which to break its billows and shelter the land from its fury. In fact, a principle of compensation seems everywhere to regulate the movements of this mighty element, and there appear to be no indications of that march of Neptune to universal empire which Mr. Lyell seems to apprehend. * In Alpine countries, where the torrents, " nature's saws," as Playfair says, " are continually at work in cutting down the mountains," geological changes on a scale of greater magnitude are constantly going on. Thus in Switzerland, the fall of an enormous mountain- mass, undermined by the action of the elements, is not an uncommon occurrence. The fall of the Rossberg in 1806, covered one of the beautiful valleys of that country with desolation, and buried many villages with their inhabitants beneath its ruins. In Savoy, near Servoz, there are the remains of a similar catastrophe, which took place in 1 749 ; and a neighbouring mountain, * " The changes of territory" says Mr. Lyell " within the general line of coast are all of a subordinate nature, in no way tending to arrest the march of the great ocean, nor to avert the des- tiny eventually awaiting the whole region : they are like the petty wars and conquests of the independent states and republics of Greece, while the power of Macedon was steadily passing on and preparing to swallow up the whole." 23 which "hangs in doubtful ruin o'er its base," threatens to renew the scene of devastation at no distant period- All mountainous countries present us with phenomena of the same description: mountain masses, like other parts of the earth's surface, being composed of strata of different density and degrees of hardness, where the base happens to consist of a soft material and to be exposed to the atmosphere, it undergoes disintegration, and the superincumbent mass is precipitated into the valley below. Then, there are the Glaciers, serving as the vehicle of transport to enormous masses of rock. They who have not seen these phenomena, can form no idea of their magnificence. They consist of enormous masses, or rivers, or as the most considerable of them are termed, in the inflated language of France, Seas of ice, Mers de Glace, formed in the valleys of the higher regions of the Alps, from the subsidence and partial dissolution of the mass of snow, which, as is well known, at a certain height varying with the latitude of the place, perpetually covers the sides and summits of lofty mountains. These have accumulated to a vast extent, and have gradually advanced into the lower valleys into the region of cul- tivation, where they have become permanently located in the midst of corn-fields and orchards ; and there, with chilly aspect, defy the rays of a southern sun. In the Alps alone, there are one hundred and thirty square leagues of this icy territory, and all other great mountain-chains present the same phenomena. The Mer de Glace of Mont Blanc, the most remark- able glacier of the Alps, is twelve or fourteen miles in length, with an average width of about a mile, and 24 fills, to the depth of several hundred feet, a deep gorge or depression in the side of the mountain. Viewed from above,* it can be compared only to a tur- bulent river of dazzling brightness, whose waves are tossed about in the wildest confusion nothing but mo- tion being wanting to complete the illusion. If any one who has seen the ocean in a storm, can picture in his imagination the effect of a sudden consolidation of the raging mass of waters when heaving in all its fury, he will have a faint conception of this singular scene. On a closer inspection, it is found to consist of deep ra- vines, and irregular ridges and masses of ice of adaman- tine hardness, bearing enormous fragments of rock on its surface, and traversed in every direction with fissures or chasms of awful depth the chilly grave of many an adventurous traveller. Some lines of a modern poet well describe a glacier. " Wave upon wave ! as if a foaming ocean, By boisterous winds to fierce rebellion driven, Heard in its wildest moments of commotion, And stood congeal'd at the command of Heaven. Its frantic billows chained at their explosion And fixed in sculpture ! here to caverns riven, There petrified to crystal at his nod, Who raised the Alps an altar to their God." As a geological agent its effects are considerable. * The point of view from which the glacier is generally ob- served, is Montanvert, about eight thousand feet above the level of the sea, where a temple as it is called, dedicated " to Nature," has been raised for the accommodation of her devotees, who come from all parts of the world to worship at this frigid shrine. 25 *The vertical masses of granite and schistose (slaty) rocks, which undergo disintegration from the action of the ele- ments, fall in large masses upon the surface of the glacier, and are carried along with it by the slow and impercepti- ble, but irresistible motion, (varying with the inclination of its rocky base,) which it has been proved to have. In this manner, huge fragments of inaccessible rocks from the very summits of the mountains, are conveyed many miles to the verge of the glacier, whence they are pre- cipitated with vast masses of congealed snow into the valley beneath, occasioning in their fall the phenomena of avalanches, those " thunderbolts of snow" whose reverberations make the mountains tremble : here they meet with the torrent by which, lashed, broken, and comminuted, they are transported to a great distance . for out of the dark icy caverns of the glacier rush with full-grown vigour, some of the mighty rivers of Europe the Rhine, the Rhone, the Po, and the Arve. In the northern regions of the world, this agent is infinitely more active, and we there find it engaged in carrying out to great distances at sea, enormous rocks and earthy masses. Thus on the frigid coast of Green- land, the glaciers, which in the Alps descend into the elevated valleys, come down in the same manner to the level of the ocean, into which they are precipitated by accidental circumstances, and from their less specific gravity, float off and sail with their heavy cargo where- ever winds and tides impel them. The northern seas are full of these ice-bergs * as they are termed, and they have been known to stray as far south as the Madeira * Berg is the German word for mountain. D 26* isles ; * and Captain Scoresby states, that he has seen masses of rock borne on these icy islets which would weigh from fifty to one hundred thousand tons. We shall hereafter have occasion to call in the aid of this powerful agent to account for phenomena where it has long since ceased to operate, but where it is inconceivable, that any other cause with which we are acquainted, could produce the effects. But of all the agents now in operation to modify the exterior surface of the globe, the volcano, and its attend- ant the earthquake, from which this portion of the world is happily exempt, are the most awful in their phe- nomena, and the most extensive in their effects. Vol- canos, in the strict sense of the term, are merely those conical chimneys or vents, by which vapours, or solid matter in a state of fusion or vitrification, are ejected by the expansive force of heat, from the internal fires, by some unknown cause excited, deep below the surface of the earth. Upwards of two hundred of these, in various parts of the world, are known to be in a state of per- manent ignition, constantly giving out fire, smoke, or vapour, and occasionally like mighty cauldrons, boiling over streams of red-hot melted matter, or with an ex- plosive force, violent beyond conception, shooting forth cinders, ashes, and vitrified matter. Volcanos generally are lofty mountains such as ./Etna, with " Entrails fraught with fire That now cast out dark fumes and pitchy clouds, * From the south pole they have also travelled northward as- far as the Cape of Good Hope. 27 Vast showers of ashes, hov'ring in the smoke, And now belch molten stones, and ruddy flames Incensed, or tear up mountains by the roots, Or fling a broken rock aloft in air."* But vents or orifices in the level surface of the country, sometimes give relief to the explosive forces, as the Geysers in Icelai/d, where steam is evolved with amazing force, and water thrown up as in artificial fountains, to a great height. In the case of elevated volcanos, the mass is most frequently formed by the gradual accumu- lation of ejected matter. Violent eruptions are generally attended by earth- quakes, and the vast extent of the effect of these, proves that the exciting cause is very deeply seated in the in- terior of the earth. Thus the shock of the terrible earth- quake which destroyed the City of Lisbon, in 1775, was felt throughout the whole of Europe, from Norway to the coast of Africa, in the Madeira isles, and the West Indies ; and at the destruction of Lima, in Peru, in 1 746, not only was the whole continent of America convulsed, but the shock was propagated across the Atlantic and sensibly perceived on the shores of Europe. Strabo, an ancient Greek geographer, first sug- gested that volcanos were " safety-valves" to regulate and restrain the action of the explosive forces in the earth's interior ; and some geologists have asserted, that it is owing to the protection which these afford, that the earth is not now convulsed as it appears to have been in former periods ; while astronomers reconcile us to the horrors and inconveniences of volcanic eruptions, by * Virgil, vEneid, lib. iii. D2 28 assuring us, that without these " safety-valves," we should in all probability be blown into space, with the shattered fragments of the globe in which the explosive materials are generated : which when recovered from the shock might move in convoy, each in its own course, round the sun, like the little planets Ceres, Pallas, and Juno, whose origin they attribute ta-a similar catas- trophe. It is certain, that where these safety-valves are absent, the surface of the earth has undergone the most considerable derangement ; the accumulation of matter round the crater of a volcano, the result of repeated eruptions, is inconsiderable, compared with the mighty upheavings of continents and islands, which our own times and historical records, as well as geological evi- dence attest. In her efforts to be free, Nature has strug- gled with the greatest violence. Thus the bed of the ocean has been raised and rent, and islands thrown up high above its level in our own times. The latest in- stance on record is that of 1831, in the Mediterranean, between Pantellaria and the coast of Sicily, the progress of which was watched by scientific observers. In 1 8 1 1 , in the Azores, a similar creation, effected in the course of a few days the formation of an island in the At- lantic a mile in circumference, and three hundred feet high was witnessed from the shores of Saint Michael's. Numbers of such instances are on record in the Azores, the Grecian Archipelago, and the Ionian isles, in con- temporary times, and Pliny enumerates several islands, which in his time were known to have arisen from the depths of the Mediterranean, at the birth of which Vulcan and Pluto had the credit of presiding, for in all cases their first appearance was attended by volcanic phenomena. 29 The sudden swelling of an extensive plain in Mex- ico* and the formation of volcanic mountains, varying, from three to sixteen hundred feet in elevation, where no volcanos had before existed, seems scarcely credible ; yet this has happened in modern times and is established on unequivocal testimony : while it is a fact in history that in 1538, a hill four hundred and forty feet high (Monte Nouvo, near Naples) was thrown up in twenty- four hours. The latter instance is near that active vent, Vesuvius ; but in Peru, where only one volcano in the whole country is known, great changes have been effected in the surface by internal violence, and scarcely a week passes without an earthquake. Hot springs are sel- dom absent in volcanic countries, and in the regions of extinct volcanos they are generally abundant. Various hypotheses have been suggested to account for the phenomena of volcanos. Heat, it is well known, is merely an intense chemical action, which may be excited in matter in a variety of ways, independent of actual contact with ignited substances by elec- tricity, rapid oxidation, friction, and other processes. The brilliant discovery of Sir Humphry Davy of the metallic bases of the earths and alkalis, which has proved that the greater part of the substances constitut- ing the earth, consist of certain delicate metals, united with the all-pervading principle oxygen, has been sug- gested as affording a clue to the process by which inter- nal heat is generated. These metallic substances, when separated from their kindred element, are so eager to re-unite with it, that the moment oxygen is placed * Jorullo, in 1750. D3 28 assuring us, that without these " safety-valves," we should in all probability be blown into space, with the shattered fragments of the globe in which the explosive materials are generated : which when recovered from the shock might move in convoy, each in its own course, round the sun, like the little planets Ceres, Pallas, and Juno, whose origin they attribute ta-a similar catas- trophe. It is certain, that where these safety-valves are absent, the surface of the earth has undergone the most considerable derangement ; the accumulation of matter round the crater of a volcano, the result of repeated eruptions, is inconsiderable, compared with the mighty upheavings of continents and islands, which our own times and historical records, as well as geological evi- dence attest. In her efforts to be free, Nature has strug- gled with the greatest violence. Thus the bed of the ocean has been raised and rent, and islands thrown up high above its level in our own times. The latest in- stance on record is that of 1831, in the Mediterranean, between Pantellaria and the coast of Sicily, the progress of which was watched by scientific observers. In 1 81 1 , in the Azores, a similar creation, effected in the course of a few days the formation of an island in the At- lantic a mile in circumference, and three hundred feet high was witnessed from the shores of Saint Michael's. Numbers of such instances are on record in the Azores, the Grecian Archipelago, and the Ionian isles, in con- temporary times, and Pliny enumerates several islands, which in his time were known to have arisen from the depths of the Mediterranean, at the birth of which Vulcan and Pluto had the credit of presiding, for in all cases their first appearance was attended by volcanic phenomena. The sudden swelling of an extensive plain in Mex- ico * and the formation of volcanic mountains, varying, from three to sixteen hundred feet in elevation, where no volcanos had before existed, seems scarcely credible ; yet this has happened in modern times and is established on unequivocal testimony : while it is a fact in history that in 1538, a hill four hundred and forty feet high (Monte Nouvo, near Naples) was thrown up in twenty- four hours. The latter instance is near that active vent, Vesuvius ; but in Peru, where only one volcano in the whole country is known, great changes have been effected in the surface by internal violence, and scarcely a week passes without an earthquake. Hot springs are sel- dom absent in volcanic countries, and in the regions of extinct volcanos they are generally abundant. Various hypotheses have been suggested to account for the phenomena of volcanos. Heat, it is well known, is merely an intense chemical action, which may be excited in matter in a variety of ways, independent of actual contact with ignited substances by elec- tricity, rapid oxidation, friction, and other processes. The brilliant discovery of Sir Humphry Davy of the metallic bases of the earths and alkalis, which has proved that the greater part of the substances constitut- ing the earth, consist of certain delicate metals, united with the all-pervading principle oxygen, has been sug- gested as affording a clue to the process by which inter- nal heat is generated. These metallic substances, when separated from their kindred element, are so eager to re-unite with it, that the moment oxygen is placed * Jorullo, in 1750. D 3 30 within their reach, they seize it, as it were, with incre- dible violence, and light and heat of the most intense description attend their embrace. * Now, although potassium, sodium, calcium, and the other metallic bases of the earths, are never found on the exterior of the globe uncombined with oxygen, it was supposed by Sir Humphry Davy, that at great depths in the interior, far removed from the action of the atmosphere, they might exist in a separate state : in which case, the acci- dental admission of oxygen by the percolation of water, would be attended with the production of that intense heat, whose expansive force we witness in the volcanic energy. He also suggested, that the proximity of vol- canos to the sea, seemed to indicate that its waters were concerned in producing the effect : and a careful ana- lysis of the vapours, the sublimations, and the other products of Vesuvius, seemed to confirm his conjecture. It is clear that water is present, from the immense quan- tity of aqueous vapour, or steam, constantly evolved, but the mere contact of water with the incandescent mass would be sufficient to account for this, without suppo- sing that the heat is generated and maintained by its decomposition. Indeed, if the constant decomposition of water were going on in the manner supposed, water being composed of eight parts of oxygen united with one of hy- drogen, when the oxygen is absorbed, an immense volume of hydrogen would be set free, and ought to be evolved either in flame or gas from the crater, in much greater quantities than it is found to be. That the vicinity of * It is this principle by which the intense light of the oxy- hydrogen microscope is produced. 31 the ocean is not essential, is proved: for although and Vesuvius, and Stromboli and Teneriffe, rise near the ocean, there are extensive volcanic regions, com- prising an area of two thousand five hundred square miles, in the heart of Asia, at a distance of more than a thousand miles from the nearest sea ; and in the central chain of the Andes, in South America, there are raging volcanos, far removed from the coast. To whatever cause, however, they may owe their origin whether to chemical decomposition, or to a permanent central heat the fact is certain, that enormous furnaces, in a state of frightful ignition, exist at intervals, in every part of the earth, at no great distance from its surface, whose action is slowly, but constantly, altering the physical features of the globe ; fusing and ejecting from beneath the hardest materials, upheaving mountains on the existing land, and raising islands from the depth of the ocean. Indeed, so extensive is the dominion of this powerful agent, that one is inclined to wonder with the elder Pliny a great Roman naturalist, who lost his life in watching the remarkable eruption of Vesuvius in the year 79 not at the frequency and magnitude of these awful phenomena, but that " a single day should pass without an explosion." Many of these furnaces have gone out at different periods of the earth's history. At an era, historically remote but geologically recent, Europe was illuminated from one end to the other with volcanic fires, compared with which, those of Etna and Vesuvius in modern times, are feeble coruscations. An examination of these de- serted forges of Vulcan in Italy, the South of France, and Germany, has presented us with some of the most 32 interesting results of geological enquiry ; and we may here witness all the effects of volcanic phenomena with- out their attendant danger and inconvenience. They belong, however, to a period antecedent to what we have regarded as contemporary times, the events of which we are considering. An active agent of change in the structure of the earth's surface, constantly but quietly at work, is found in the organic creation. Rock-formations of vast ex- tent, are in progress in many parts of the ocean, effected by the labours of the well-known coral animals, or animal plants * as they are termed, from the circum- stance of their branch- like habitations, always being found springing from rocks. These polyparia, in com - mon with the other shelly inhabitants of the ocean have the extraordinary property of secreting (from whence de- rived is not known) an enormous quantity of carbonate of lime in the construction of their dwellings. Affixing themselves to the submarine mountains or elevated portions of the bed of the ocean, they spread their my- riad arms, and rapidly build up the ramified substance, which is in this country admired for its beautiful forms. In their progress upwards one generation builds upon the ruined and deserted habitations of another, calcareous sand and other cementing matter furnished by the ocean, is mixed with the mass, and the whole becomes a consolidated limestone ; which, as it emerges from the water, decomposes and becomes eventually the abode of vegetation, birds make it their resort, animals accidentally transported by the waves find in it a refuge * Zoophytes. 33 from a watery grave, and man at last finds his way thither, erects his habitation, cultivates the decom- posing soil, now enriched with nutritive matter and adorned with vegetable productions, and calls himself " lord" of this new creation. This creative process is going on to an incredible extent in various parts of the world. Reefs, as these newly-built islands are called, extending many hundred miles, are forming in the tropical regions of the Pacific. The Indian ocean teems with this world-building population, and its insidious encroach- ments are fast filling up the Arabian gulph. Springs, although upon a small scale, are actively engaged in adding to the mineral masses in the earth's superstructure. All waters issuing from beneath the surface of the ground, contain more or less of earthy matter in solution, and it is to these extraneous ingre- dients that the " crystal spring" owes its clearness and agreeable taste. Lime is the predominating substance in mineral waters, in which it is held in solution by means of carbonic acid and where this element is abun- dant as in the case of thermal, or hot springs, the water is sometimes saturated with the carbonate. The car- bonic acid being, in these cases, withdrawn by the ab- straction of heat, and other circumstances, a large de- posit of limestone takes place, as in the Solfatara, and on the banks of the Anio, at Tivoli, and in many other situations in the neighbourhood of Rome : the princi- pal buildings in " the eternal city," in fact, are built of this rock of modern origin. The rapidity with which this concretionary deposit is effected is not less incredi- ble than the great extent of its formation. I have seen specimens of travertin or tufa, as it is termed, equal in 36 Lickey Hill, a remarkable mass of quartzose sandstone, near Birmingham, in all the valleys diverging south- wardly from that part of England, and has shewn in his " Reliquae Diluvianee," that they were drifted to a great distance along the valleys of the Evenlode, the Cher- well, and the Thames, through two remarkable openings in the range of limestone hills near Banbury, and at Moreton-in-the-Marsh, the only points -where this effectual obstacfc to their dispersion in that direction, appears to have given way to the denuding torrent. The citizen of London, whose travels had never ^xtended beyond the district of the two-penny post, and the range of whose ideas was, perhaps, confined within still narrower limits, would hear with surprise and incredulity, that the pebbles which he sees dug from beneath the soil of Hyde Park, had travelled from the neighbourhood of Birmingham. Yet this is as easily proved, as that Westminster bridge is built of Portland stone, and the new London bridge of granite. ^ A vast accumulation of gravel covers- ^me -iastern side of Leicestershire, and runs through the adjoining county of .Northampton, from "which, according |o the statement of Conybeare, a complete suite of geological specimens might be obtained. Thus, in the deep gravel of Leicestershire, I have found specimens of the echinus and the encrinite, buried in the same bed, although they belong to widely-different ages, and were originally deposited in localities far removed from each other. These gravel beds contain also, washings from the neighbouring coal-formation, which in many cases, as at Billesdon, from their peculiar specific gravity, 37 have assumed a stratified arrangement a circumstance which has deceived many an inexperienced observer.* In the gravel are frequently found the bones of quadrupeds and other animals, which, in some cases, belong to species which now inhabit the countries where they are found ; but more frequently, in these northern latitudes, correspond with those which belong to tropical climates, such as the elephant, rhinoceros, hippopotamus, hyaena, &c. Thus the tyones of elephants have been found in the gravel beneath the metropolis, under Gray's Inn lane, Waterloo-place, and in various other situations, and in fact, more or less in all the gravel-pits of the environs. Animal relics of the same* description have been found under similar circum- stances in every part of the country, and not only in this country, but throughout Europe and America. When these remains were first discovered in England, they were supposed to be the bones of giants ; but naturalists having exploded this idea, the next hypo- thesis ^ras, that they were relics of the elephants brought over with the Roman armies ; but when it was discovered that they belonged to extinct species, and that they were generally associated with bones of the * Metallic fragments or pebbles, arranged in horizontal layers, are also sometimes found in gravel beds formed of the wreck of the rocks which originally contained them, as in the Vale of Clywdd in North Wales, where abraded fragments of lead intermixed with stags' horns and elephants' bones, are found in sufficient abun- dance to be worth working. Between Lake Superior and the Mis- sissippi, lead is obtained under similar circumstances : and gold, it is well-known, is generally extracted from the alluvial gravel of South America. 38 rhinoceros and hippopotamus animals which were not likely to have followed in the train of the Roman legions, this idea was also abandoned. It was not until they ceased to become objects of antiquarian research, and came under the cognizance of geologists, that correct opinions as to their origin began to be entertained ; and even then, the extraordinary circumstances sometimes connected with them, seemed to defy the application of any general hypothesis. Thus they have not only been found in the gravel and superficial deposits of earthy matter in the valleys of this country, and throughout Europe, from which an uncongenial climate has long extirpated them, but at inaccessible heights, in every part of the world, in Europe, Asia, and America. Such is the profusion of elephants' tusks found buried in the soil in many parts of Russia, that they have been made an article of commerce, chess-men and toys being constructed of this antediluvian ivory. Humboldt found bones of the mastodon, an extinct species of elephant, at eight thousand feet above the level of the sea, near Santa Fe de Bagota in South America, and another species, in the Andes near Quito, at an equal elevation ; and there are bones of horses, deer, and other animals incrusted with calcareous matter, preserved in the museum of the Royal College of Surgeons at London, which fell with avalanches from the regions of perpetual snow in the Himalayan moun- tains, at the height of sixteen thousand feet ; which, as they appeared to fall from the clouds, the natives sup- posed to be the bones of genii a supposition less repre- hensible than that of the chief magistrate of Lucerne, who, without hesitation, pronounced the bones of ele- 39 phants dug up beneath that city, to be relics of those unfortunate beings whom an incensed Deity hurled from their high estate, the rebellious angels : and adopting them as the ancient tutelar deities of the place, he caused their bones to be collected with the most scrupulous care, and decently interred, and imaginary portraits of their collossal forms to be placed in a con- spicuous part of the city, in order to inspire the Lucernese at once with piety, and sympathy for these miserable beings. Two theories were at first adopted by geologists to account for the presence of the remains of animals so unlike the races at present existing in the countries where they are found. First, that they were transported thither from their native regions in the south, by the same agency which rolled together the gravelly masses in which they have been buried : secondly, that the animals now confined to tropical climates, uncontrolled by the dominion of man, at remote periods, wandered occasionally beyond their natural limits, as tigers in every respect corresponding with those of Bengal, now roam into Siberia as far north as the parallels of Berlin and Hamburgh. Subsequent observations unsettled both these conclusions. It was soon observed that these animal-relics, did not exhibit, like their travelled asso- ciates the pebbles, any considerable marks of attrition, consequently that they could not have been removed far from the spot where the animals died. And the discovery of a rhinoceros and an elephant * in a perfect * The discovery of the rhinoceros with its skin and hair entire, was made as early as 1770. It was found enveloped in sand, on E 2 40 state of preservation, encased in frozen mud in the north of Russia, unequivocally proved that those animals had perished on the spot where their carcases were found preserved from decomposition. That they were not occasional visitors to the arctic circle has been also ascertained, for it appears from the account of Captain Beechy's expedition, and the report of M. Hedenstrom, who explored the shores of the Icy sea by the direction of the Russian government, that hundreds of elephants, rhinoceroses, oxen, and other animals are buried in the frozen ground of the circumpolar regions of both the great continents, from the American side of Behring's Straits, to the aestuary of the river Lena, in Asiatic Russia. Now although tigers, being carnivorous, may the banks of one of the tributary streams of the Lena in Siberia. The elephant now in the museum of Saint Petersburg, was dis- covered and laid open in 1799, but not removed until 1804, during which interval, the hungry dogs and wolves of that inhospitable climate, made many a meal of this antediluvian morceau, and a Tungusian chief stole the tusks. But although thus despoiled, it is still a very respectable specimen of the ancient inhabitants of the world : as will appear from Dr. Granville, who, in his " Tour to St. Petersburgh" says, " I stood before the gigantic animal, by the side of which, the skeletons of even an African and Asiatic elephant looked insignificant, amazed, and perfectly awed at its stupendous structure. The manner and locality in which it was discovered were additional causes of surprise : for instead of being fossilized, it has retained the skin, the very flesh and the powerful tendons of the legs, in a recent state, as if its own gigantic elements, aided by the preserving influence of perpetual snows, had been sufficient to resist those extraordinary changes, which geological commotions seem to have effected in other organized beings of the antediluvian world." 41 travel into high latitudes in quest of food, elephants and oxen herbivorous animals were not likely to migrate from the " luxurious south" to these " Thrilling regions of thick-ribbed ice," in search of pasture. And although the circumstance of this antediluvian race of elephants having been clothed with long hair, is pro tanto a proof that they were adapted for a climate much colder than that in which the present species flourish, it is inconceivable that these huge masses of flesh and bone could have subsisted on the insubstantial sustenance afforded by the scanty vegetation the lichens and mosses of the arctic regions at the present day. The inference, there- fore, is, that a considerable change in the climate as well as in the inhabitants of these countries, has taken place : and that this change was suddenly produced, is inferred from the congelation of the fluid mass in which the animals were enveloped, having taken place before de- composition had time to affect their fleshy carcase's. In addition to the comminuted fragments of rocks, gravel, and easily- transported matter, which partially envelope, as with a mantle, the exterior of the globe, there are found dispersed in various parts of the world, sometimes buried in the gravel, and more commonly resting on the surface of the soil, innumerable masses or huge blocks of rock, the transport of which by any agent with which we are acquainted seems impossible. Thus the countries bordering on the Baltic, Prussia, Poland, Russia from St. Petersburg to Moscow, and Germany, even to the foot of the Carpathian mountains, are covered, and in many places rendered absolutely 3 42 sterile by the vast accumulation of these transported boulders ; which, from their similarity of character, are proved to have been derived from the Alpine chains of Scandinavia, and other countries on the opposite side of the Baltic. The same phenomena may be observed in this country. On the limestone hills near Kendal and other situations, blocks of granite, some twelve feet in diameter, are found in great abundance, which must have been stripped from the mountain of Shap near Penrith. Indeed, Professor Sedgwick has lately ob- served that these granitic relics of Shap, have been rolled over the great central chain of England into the plains of Yorkshire, and even carried to the eastern coast ; and Mr. Phillips states that in some parts of Yorkshire, pebbles, and blocks of rock are found, which must have come from Norway, and even, according to Dr. Buckland, from the coast of Labrador, and it is observable that there is a marked distinction between the fragments drifted from distant localities and those which are plainly derived from the wreck of neigh- bouring hills ; the latter being less rounded by attrition than the former. Looking at the vast distance which separates these countries, and the " great gulph" of ocean which now divides them, and viewing, moreover, the enormous size of many of these travelled rocks, * and the elevated situations in which they are sometimes found, we are almost disposed to doubt the accuracy of the conclusions at which geologists have arrived, and would * The mass of granite which forms the base of the celebrated statue of Peter the Great, at St. Petersburgh, is a travelled fragment found in the marshy plains of the^Neva, and it weighs twelve hun- dred tons. 43 gladly get rid of the difficulty, by assuming that these anomalous masses had existed from the beginning of time where we now see them, or were the spontaneous growth of the soil on which they rest. Geologists, however, are not to be startled by the appearance of difficulties, and it is a singular circumstance, that in the present day a satisfactory solution to this problem is found in a theory which immature philosophy pronounced to be inadmissible.* In all the cases adduced, the impelling force appears to have proceeded from the north, and water is the only agent with which we are acquainted, capable of producing the effect. Had the diluvial remains been confined to the coast, we might naturally have referred these phenomena to the action of the existing seas, but they extend far inland, and their dispersion everywhere seems to indicate the same direction of the impelling force. For instance, in the very heart of England, the hills of Charnwood Forest, (entitled to veneration from the circumstance that, unassuming as they are, they can boast of a higher antiquity than the mighty Alps,) have undergone the action of an abrading force which has dispersed fragments of its rocks in a southerly direction the larger masses being scattered in the red sandstone plains of Leicester- shire, the smaller, rolled as far south as the chalk escarpment near Dunstable. In the gravel beds on the summit of the Gog-Magog hills, near Cambridge, Professor Sedgwick found the joint of a basaltic pillar, which must have travelled from the Hebrides or the Giant's Causeway. * " Y a-t-il eu un temps ou le globe a ete entierement inonde ? Cela est physitjueiBent impossible." Voltaire, Diet. Phil. 44 The inference from all these facts, is, that at a period not very remote, a violent torrent overwhelmed every part of the earth's surface, tearing up in its fury the pre-existing rocks, breaking them into fragments, and transporting them to the situations in which we find them : that in these northern latitudes the denuding force appears to have rushed with inconceivable violence from the polar regions towards the south : that this rush of waters was not confined to one hemisphere, but took place alike on the European and American con- tinents, for the northern states of the latter are literally covered with erratic blocks, which are evidently frag- ments of the mountains within the arctic circle : and a thousand instances might have been added to those adduced, of the southerly dispersion of these antediluvian relics throughout Europe. It yet remains a question for geologists to determine, whether these phenomena were produced simultaneously, or whether there are not proofs in the superficial beds of transported matter, of a series of catastrophes, such as that to which we have referred. In the neighbourhood of the Alps, where the most remarkable instances of the dispersion of erratic blocks are to be found, there are unequivocal proofs of a succession of these effects, and the direction of the removing force, is not, as in this country and in the north of Europe and America, towards the south : but on every side of the great Alpine chain, fragments are scattered, as if some violent repulsive force had thrown them off in every direction from the centre. The granitic boulders on the Jura mountains attract the attention of all travellers, from the obvious distinction 45 in the mineral character, and the extraordinary position of these masses. Switzerland, as every person acquainted with the geography of Europe is aware, is mainly constituted of an undulating valley, situated between two great mountain ranges, the Alps on the south, and the Jura mountains on the north-west. Now granite only makes its appearance in the Alps, limestone con- stitutes the mass of the Jura mountains, and the intervening space is filled up by a variety of local deposits. But the sides of the Jura mountains facing the Alps, here one continuous and almost per- pendicular wall of limestone, are literally covered, wherever a ledge or sufficient space exists for their support, with blocks of granite of various sizes, from the smallest fragments to masses of enormous mag- nitude, sometimes perched on the declivities at the height of four thousand feet above the intermediate valley. And git is not only on the side of these mountains, but wherever an elevation of considerable magnitude intervenes, there we find an accumulation of these detritus, as at the entrance of all the valleys descending from the Alps where a mountain mass has intercepted the current, as the engraving will illustrate. Thus, on the Grand Saleve (>), a limestone mountain overhanging the city of Geneva, and stretching across the entrance of the valley descending from Mont Blanc 46 (a), blocks of granite derived from the summit of that remarkable mountain, and corresponding precisely with those found on the flanks of the Jura (d) , cover its southern face, from the base to the summit, although forty miles distant from the parent rock ; but neither on the surface nor in the mass of the interposed deposit (c) , have these granite boulders been observed, although it is itself a conglomerate of transported matter. The inference therefore is, either that the date of its formation is subsequent to the action of that of the denuding forces which removed the granitic fragments to their present position, or that the waters by which these masses were transported had ceased to convey such heavy burdens. From the circumstance of the immense size of these detached masses, some of them containing fifty thousand cubic feet, and their having in all cases preserved their angular shape, not being rounded as if rolled by torrents, it has been inferred by Von Buch, and others, that they must have been borne on the surface of glaciers, which, as we have seen, are now employed on the sides of mountains, and in the ocean, in removing similar frag- ments of rocks. The facts we have been considering are fortunately not the only records we possess of the universal catas- trophe to which I have pointed, as affording the only adequate explanation of these interesting phenomena. It will occur to all who have directed their attention to the subject, that we have in the Mosaic history as clear an account of this great event as the nature of the circumstances entitle us to expect. " In the six hun- dredth year of Noah, in the second month, and the seventeenth day of the month, the same day were all the 47 fountains of the great deep broken up, and the windows of Heaven were opened, and the waters prevailed and were greatly increased, and all the high hills that were under the Heaven were covered." " If there be any fact well established in geology," says the great Cuvier in his admirable " Discours Preliminaire" " it is this, that the surface of our globe has suffered a great and sudden revolution, the period of which cannot be dated further back than five or six thousand years. This revolution has on the one hand engulphed and caused to disappear the countries formerly inhabited by men and the animal species at present best known, and on the other has laid bare the bottom of the last ocean, thus converting its channel into the now habitable earth." Cuvier was not predisposed to arrive at this conclusion, his testimony therefore, is not to be despised. But the evidence is irresistible. The geologist who had never heard of Noah, or the writings of Moses, would inevitably be driven to the same conclusion. Those who argue with Mr. Lyell, that all the modifications of the earth's surface have been produced by the slow, but gradual operation of causes now in action, can never get over the proofs of this universal cataclysm ; in comparison with which all the revolutions and convulsions of modern times dwindle into insig- nificance. Great and awful, however, as are these effects, when measured by the contracted span of our ideas, they are as nothing when considered with reference to the globe the vast mass of matter, upon which they occur, and insignificant in fact, compared with the mighty boulevfrrsements which have prostrated the 48 high hills, and reared" oceans' caves" into mountains- such as those which produced the shelly summit of Snowdon, and buried in the dark profundity of the earth the beautiful vegetation of its surface. But before we arrive at the consideration of these, there are other interesting relics of the antediluvian world to examine, and changes which may be referred to the action of existing causes, operating at periods which cannot with precision be determined subsequent however to the consolidation of the stratified masses which we shall hereafter have to investigate. The gravel beds are not the only tombs of the antediluvian population,* but Nature appears to have prepared also catacombs for their reception. Every- where, but more especially in the limestone rocks, we find cavities or fissures partly or wholly filled up with the bones of animals and extraneous substances. When first discovered, they were supposed to be unequivocal proofs of the deluge, and that the bones thus entombed were the relics of animals who had fled into these situations to escape destruction. Bui many of these caverns are now ascertained to have been, for a long period, the dwellings, or dens of hyaenas, bears, and other animals addicted to subterraneous resorts : such as the cave at Kirkdale, in Yorkshire, so carefully explored and described by Dr. Buckland, which, although it contains the bones of a great variety of animals, is proved to be have been a hyaena's den, from the bones of that animal predominating, and those of other species bearing the marks of the teeth of this voracious beast. In this case, as in others in England, Germany, and elsewhere, the bones are enveloped in consolidated 49 mud, which appears to have flowed in at the aperture, and to have covered up, indiscriminately, both hyaenas and their prey. In some instances, pebbles have also rushed in with the torrent, and left the marks of violent action upon the upper surface of the stratum of bones. The entrances of these caverns have generally been filled up either by transported pebbles, or an accumulation of local fragments, so that their discovery is entirely accidental. In some cases, as in the osseous breccia, (bony breaches,) so abundant on the coasts of the Medi- terranean, the extraneous matter in which the bones are imbedded, has formed a mass of stone harder than the rock in which they exist, and there are other remarkable features of these osseous breccia, which not only indicate their great antiquity, but point to many extraordinary changes since they existed as open fis- sures : thus their entrances are found at great elevations above the level of the sea, in the face of precipitous rocks, yet there are decided proofs that they were once below the surface of the water, as alithodomous or stone- piercing shell, (an inhabitant of the sea,) has in many cases penetrated the sides of the apertures, and left its remains adhering to the rock. At a subsequent period the cavity was partly filled with matter transported from a distance : then with animal bones, which became mixed and cemented together by a deposit of carbonate of lime, from the percolation of water through the mass of the rock in which the fissure was formed : and again, the rock itself was lifted up, or the sea lowered to its present level. In other cases, as at the rock of Gibraltar, there are 50 decided proofs that the breccia have been furnished with their organic contents since the elevation of that re- markable mountain, and anterior to the deluge: the bones being those of animals and birds which acci- dentally fell, or were carried by beasts of prey, into the fissures, which, though now filled with calcareous and other matter equal in hardness to the limestone itself, may be traced to the surface at great heights, where the entrances are covered up with rolled fragments of jasper, agate, quartz, and other debris, brought from a great distance by the diluvial waves which washed over this lofty insulated rock, in common with all " the high hills under heaven," and left traces of its action less remark- able, but not less equivocal than the transported blocks on the plains of Poland, or the masses of granite upon the Jura mountains.* But again, at the base of the same * "The uncovered parts of the rock (of Gibraltar) expose to the eye a phenomenon worthy of some attention, as it tends clearly to demonstrate, that however high the surface of this rock may now be elevated above the level of the sea, it has once been the bed of agitated waters. This phenomenon is to be observed in many parts of the rock ; it consists of pot-like holes of various sizes, hollowed out of the solid rock, and formed apparently by the attrition of gravel or pebbles, set in motion by the rapidity of rivers or currents in the sea. One of those which had been recently laid open I examined with attention, and found it to be five feet deep, and three in diameter : the edge of its mouth rounded off, as if by art, and its sides and bottom retaining a considerable degree of polish. From its mouth, for three-and-a-half feet down, it was filled with a red argillaceous earth, thinly mixed with minute parts of transparent quartz crystals; the remaining foot-and-a-half, to the bottom, contained an aggregate of water- worn stones, which were from the size of a goose's egg, to that of a small walnut, and 51 rock there are other fissures, which have been filled in modern times with concretionary matter, principally formed of pebbles of the limestone of which the hill is composed, interspersed with the bones of birds, which in the breeding season nestle in the clefts : and in one of these concretions Major Imrie informs us, part of a green-glass bottle was discovered, proving its recent formation. And so, in this country, and in every part of Europe, there are cracks or open fissures in limestone rocks, such as those at Buncombe park, and at Selside near Ingeborough, in Yorkshire, into which animals browsing upon the surface have accidentally fallen and perished, and where, as Professor Sedgwick observes, great masses of bony breccia must have accumulated in the course of two or three thousand years. Again, there are other caverns, originally dens of bears and hyaenas, into which man has, at a subsequent period, retreated and perished, and left his remains with those of his uncongenial predecessors : as at the cavern at Bize, and those near Lunel-viel in France, where the bones of quadrupeds, such as the rhinoceros, bear, and hyaena, are confusedly intermixed with those of the human species. These dissimilar relics might have been simultaneously brought together from distant situations,by the rush of water which conveyed the other consisted of red jaspers, yellowish- white flints, white quartz, and blueish- white agates, firmly combined by calcareous spar. In this breccia / cou Id not discover any fragment of the mountain -rock, or any calcareous matter except the cement with which it is combined. This pot is nine hundred and forty feet above the level of the sea." Major Imries Mineralogical Description of Gibraltar. F 2 extraneous substances into the cavern ; but the more probable inference, and the one adopted by those who have examined the facts, is, that their occurrence together is accidental, and their production referrible to distinct periods : that the animals whose bones predominate, were the first tenants of the cavern : that the enormous accumulation of bones was gradually effected, during the long period in which wild beasts had uncontrolled dominion in the forests of Europe : when every hole appears to have been the lurking-place of hyaenas, and every cave a bears' den ; that at a subsequent period when these races had been extirpated, man found in these vacated caverns a refuge from persecution, a secure abode, or a place of sepulture : thus, we see a single cavern may exhibit the monuments of several distinct and widely-separated epochs : and we may judge with what impropriety all these phenomena were referred to the deluge. The difficulty which the general absence of human bones in these reliquce diluviance, presents, was soon felt by geologists who adopted this hypothesis ; and it was supposed that the circumstance could only be explained by the supposition that the world, or at least that part of it in which these animal remains are found in such abundance, was but thinly peopled at the time of the deluge : or that the antedilu- vian population was then confined to the Asiatic regions, " the cradle of the human race," * which geologists have not yet explored. * Mr. Weaver, with whom Dr. Buckland coincides, says, " the satisfactory solution of the general problem as far as it relates to man, is probably to be sought more particularly in the Asiatic 53 There appears, cl priori, to be no satisfactory rea- son why human bones should not have been buried in common with those of animals : the indestructible ingredient, phosphate of lime, exists in them in equal abundance, and we know that in modern times human skeletons, accidentally enveloped, have undergone petri- faction, or have been preserved in their original state several thousand years. * We can only account for their absence in the diluvial relics by the supposition alluded to, that our race occupied only a limited portion of the earth's surface, when destruction overtook " all flesh wherein was the breath of life." Europe, it is clear, during the period of the occupancy of the caves by the ferocious animals, whose bones they enclose in such prodigious quantities, could not have been inha- bited by man. f regions, the cradle of the human race : and that another interesting branch of enquiry connected with it, is, whether any fossil remains of elephant, rhinoceros, hippopotamus, and hysena, exist in the diluvium of tropical countries : and if they do, whether they agree with the the recent species of these genera, or with those extinct species, whose remains are dispersed so largely over the temperate and frigid zones of the northern hemisphere." * " In a turbary on the estate of the Earl of Moira, in Ireland, a human body was dug up, a foot deep in gravel, covered with eleven feet of moss ; the body was completely clothed, and the garments seemed all to be made of hair. Before the use of wool was known in that country, the clothing of the inhabitants was made of hair, so that it would appear that this body had been buried at that early period ; yet it was fresh and unimpaired." Dr. Rcnnie, Bss&lfap. 521. f An idea of the vast number of animals entombed in these natural cemeteries, may be formed from Dr. Buckland's account of F3 54 The correspondence of the animal remains in caves with those in the superficial beds of loam and gravel is a remarkable fact, but it does not prove that they existed at the same period, or were simultaneously de- stroyed ; for it is evident, a much higher antiquity must be assigned to a large portion of the inhabitants of those caves, in which countless generations had lived and died, and a vast accumulation of animal ruins had been effected, anterior to the action of the diluvial torrent, which overwhelmed the surviving individuals, and covered up the whole with extraneous matter. Besides, in many cases, the caves had not only been occupied for centuries, but these last effects were produced they were abandoned and closed up long before the surface of the earth experienced the violent denuding effect of the the cave of Kiihloch in Franconia. He says " There are hundreds of cart-loads of black animal dust entirely covering the whole floor, to a depth which must average at least six feet, and which if we multiply the depth by the length and breadth of the cavern, will be found to exceed five thousand cubic feet. The quantity of animal matter accumulated on this floor is the most surprising and the only thing of the kind I ever witnessed ; and many hundred, T may say thousand individuals, must have contributed their remains to make up this appalling mass of the dust of death. It seems in great part to be derived from comminuted and pul- verised bone ; for the fleshy parts of animal bodies, produce by their decomposition, so small a quantity of permanent earthy residuum, that we must seek for the origin of this mass principally in decayed bones. The cave is so dry, that the black earth lies in the state of loose powder and rises in dust under the feet ; it also retains so large a proportion of its original animal matter that it is used occasionally by the peasants as an enriching manure for the adjacent meadows." Reliquoe Diluviance, p. 138. 55 deluge. This, the remarkable position of the entrances of many of the bony caverns, especially those of Ger- many, seems to prove. These are very commonly in inaccessible situations in the face of precipitous rocks, such as those of the remarkable caverns of Rabenstein, Kiihloch, and Schneiderloch, in the gorge of the Esbach river in Franconia, described by Dr. Buckland. In these instances the original entrances of the caverns are supposed to have been, not in the perpendicular sides of the rocks where they are now found, but on the surface of the elevated ground through which the river-gorge has been excavated. This, the wood-engraving will render more intelligible. The entrance to the cave of Rabenstein is seen on the right, in the face of the cliff beneath the chapel (a) ; the river Esbach flows down the centre of the denuded dell ; and the caves of Kiihloch (&), and Schneiderloch (c] , are midway up the sides of the opposite cliffs. Dr. Buckland very fairly infers that the high ground on each side of the gorge, was originally continuous, and that the mouths of the caverns were on the level of the country in the space now occupied by the valley, as at 56 Scharzfeld and other similar situations, and that at these entrances the pebbles and diluvial mud which envelope the bones were introduced : at the same time, he sup- poses, the upper part of the caves were cut off, and the gorge excavated : but there appears some inconsistency in attributing to the same agency, effects so dissimilar as the quiet deposition of a thin stratum of mud in the caverns, and the exertion of a force so violent as to cut out a channel in the solid rocks more than a hundred feet deep ; one of these caves, moreover, like that of Kirkdale, exhibits no traces of the diluvial action in its interior : the aperture, therefore, must have been pre- viously closed. All the circumstances, indeed, justify the inference that these effects have been produced by a succession of causes operating at distinct periods ; although the phenomena of osseous caverns and breccia generally, may be referred to the last transient rush of waters over the surface the great debacle whose effects we everywhere discover.* * Mr. Lyell, and other writers, suppose that the earth's sur- face underwent no great modification, at the era of the Mosaic deluge, and that the strictest interpretation of the scriptural narra- tive does not warrant us in expecting to find any gelogical monu- ments of the catastrophe. That there was no impetuous rushing of the waters, Mr. Lyell argues, the olive branch brought back by the dove, is an unequivocal proof, as it is a clear indication that the vegetation was not destroyed. His geological objections to the universality of the flood are 1st, That there are cones or minor volcanos on the flanks of Etna, at least ten thousand years' old, which have escaped the denuding force. 2nd, There are living trees, such as the Taxodiunt of Mexico, (one hundred and seventeen feet in circumference,) which according to De Candolle, have stood more than five thousand years. 3rd, That many alluviums are of 57 Dr. Buckland deduces another consequence from the inhabited caves and osseous fissures, i. e. that the relative permanent position of sea and land was not materially altered by the deluge, but that the antedilu- vian surface or at least a large portion of the northern hemisphere was the same with the present. This opinion, though in the main a legitimate conclusion, must be more remote antiquity than the period assigned to the deluge. 4th, That the extinct volcanic region of France, respecting the action of which history and tradition, although they go back two thousand years, are silent, exhibits no traces of the diluvial wave, the cones of loose cinders and craters, several hundred in number, not having been disturbed since their eruption. The scriptural deluge he regards as a preternatural event, far beyond the reach of philosophical inquiry, whether as to the secondary, causes employed to produce it, or the effects resulting from it. It is not a little singular, that a theorist who with Titanic hand lifts up mountains at the equator, and sinks the elevated regions of the north beneath the ocean, in order to account for the change of climate which geological phenomena prove to have taken place, should be so scrupulous about the introduction of secon- dary causes. The difficulties he has stated are merely negative, and the grounds upon which they are raised purely hypothetical, while the positive proofs the more obvious diluvial phenomena remain unexplained. Thus the remote antiquity assigned to the Etnean cones, is deduced from the effects observed to take place from the action of the volcano in modern times. Cuvier expresses in strong terms his opinion of the inadequacy of existing causes to the pro- duction of geological phenomena : " C'est en vain que Ton cherche dans les forces qui agissent maintenant a la surface de la terre, des causes suffisantes pour produire les revolutions et les catastrophes dont son enveloppe nous montre les traces ; et si Ton veut recourir aux forces exterieures constantes connues jusqu' a present, Ton n 'y trouve pas plus de ressources." 58 admitted only with modifications : * the force which denuded the valleys might have excavated the basins of shallow seas ; and we have seen how the coasts of the Mediterranean, where the osseous breccia exist in such abundance, have been disturbed. And we have other proofs of similar disturbances yet to examine. A remarkable feature of our coasts are the sub- marine forests as they are termed buried trees, which lie in immense numbers beneath the soil of our fens and other flat lands. The level country adjoining the coast from the Hum her to Norfolk, an immense tract of land which the industry and wealth of modern times has fertilized, is filled with the vestiges of these ancient forests, although not a tree at present enlivens the dull monotony of its surface. These vestiges consist of the stems, branches, and roots, and even leaves, of the oak, birch, fir, and other trees and shrubs, sometimes found in a state of perfect preservation, the wood retaining its natural fibre and original hardness. In many places they are found beneath a sedimentary deposit, such as that now left by the adjacent sea on the coasts, of con- siderable thickness, as if an inundation of the ocean had taken place since the destruction of the forests. The * "Wherever such caves and fissures occur, i. e. in the greater part of Europe, and in whatever other part of the world such bones may be found under similar circumstances, there did not take place any such interchange of the surfaces occupied respectively by land and water, as many writers of high authority have conceived to have immediately succeeded the last great geological revolution by an universal and transient inundation which has effected the planet we inhabit." Reliquce Diliiviance, p. 163. 59 roots are in general affixed to the substratum of clay, but the trunks appear to have been prostrated by some violent agency. The most difficult circumstance to explain, is the position of these buried forests, which is generally below the level of the sea, beneath which in fact they are known to extend. A rise in the level of the ocean upon our coasts suggests itself as the obvious mode of explaining the difficulty : but in other situations beaches thrown up by the waves would lead us to the opposite inference. The instance given by Mr. de la Beche, of the deserted beach near Plymouth, is a good illustration of this fact : a is a sea-beach formed of an accumulation of rounded pebbles, fragments of shells, and sand, precisely such as the sea at present leaves, resting upon the inclined limestone rock (b) at the height of thirty feet above the present high-water mark (c) : this is again covered up by a deposit (d) of loose angular fragments of the subjacent limestone, which have slipped down over the beach. Similar elevated beaches occur along the line of the neigh- bouring coast from which the inference might fairly have been deduced, that the level of the sea had fallen. But again, not further distant than Mount's bay, in Cornwall, the ebb of the tide exposes to view a submarine forest. How then can phenomena so anomalous, and apparently contradictory, be explained by any general hypothesis ? Local elevations of the land on the one hand, and a 60 partial subsidence of the sea on the other, produced by some unknown internal agency, afford the only possible solution of the enigma. Every coast, more or less, exhibits the same com- plicated changes. On the shores of the Baltic they had long been observed, and an opinion was entertained that the waters of that sea had been falling for ages, when Celsius, a Swedish philosopher, thought he had estab- lished the rate at which this subsidence had proceeded, namely, forty-five inches in a century. On the other hand it was contended that there was equal reason to suppose that they were rising, as trees had been found growing close to the level of the water, which the number of the concentric rings in their trunks proved, had stood at least four hundred years on the spot ; consequently according to the hypothesis of Celsius, they must for a long period have grown beneath the water, which was impossible. But the fact that ancient ports had become inland towns, and that many parts of the Gulf of Bothnia were gradually becoming land, could not be denied. Von Buch, therefore, suggested that the land was in some places insensibly rising; and to verify the opinion, lines were chisseled along the coast, by which it was thought to be proved that the mean level of the greater part of the Baltic was falling. This might have been effected by the deepening of the channel of efflux (the Sound) , but as the waters have sunk at Stockholm and not at Abo, on the opposite coast, this hypothesis was untenable. In this state of things, geologists set about determining the subject, and M. Brongniart soon dis- covered on the coast of Sweden, shells identical with the species now existing in the sea below, adhering to rocks on 61 which the water- had evidently rested a long time, a^the height of four hundred feet above its present level 5 thus proving, what before had not been suspected, th$t the land had been upheaved ; and Mr. Lyell, who has travelled through these countries since the publication of his interesting work, has observed other facts which completely establish this opinion. It is difficult to determine the precise position which these events ought, to occupy in the earth's chro- nology, but were we to judge of their antiquity by the changes which have been produced in this part of the world, during the historical period, we should assign to them a very remote date. Thus, innumerable works of art constructed by the Romans on the coast from Bel- gium to Alexandria, prove that no considerable alteration has taken place in the relative level of land and sea, throughout Europe, since the period when that renowned people" bestrode the world like a colossus." The tumuli or earthy mounds raised by the ancient inhabitants of this island and other parts of Europe, over the bodies of their warriors and illustrious dead, which are known to have existed at least two thousand years, remain to this day undisturbed, except by the antiquarian. Roads and bridges constructed by the Romans, exist to this day unimpaired, in the volcanic regions of France, where there are all the appearances of recent volcanic action, although in the time of Caesar, who describes the same appearances, history and tradition were silent as to the period of their eruptions. Rome, " the eternal city'' itself, as before observed, is built of stone derived from rocks of modern origin, and its celebrated hills owe G 62 their elevation from the bed of the Mediterranean, to volcanic action of recent date ; half the peninsula of Italy in fact, is known to have arisen from the depths of the Adriatic ; Venice, its far-famed " queen, " standing upon the lowest and last-raised portion of its oozy bed. Had Nature exhibited an invariable constancy in her movements had a uniformity of operation been observed throughout every period of the earth's history, in the causes which have produced the geological phe- nomena, we should only require to know the amount of diurnal action, in order to calculate the effects produced in a lapse of ages, in the same manner as the laws which govern the planetary system, and the remotest bodies in space, are deduced from observations on the motion of bodies upon the surface of the earth : and taking the facts above adverted to, which seem to indicate a state of quiescence or an inappreciable change during the last two thousand years, we must go back far beyond the deluge for the most recent of geological changes. But the reasoning is delusive ; the physical constitution of the globe has suffered from repeated convulsions : the energies of Nature have been exerted in paroxysms, succeeding intervals of repose, and not in uniform and constant efforts. It was no security to the inhabitants of Herculaneum, who might thus have reasoned, that Vesuvius* had been dormant from the earliest times to which tradition reached, nor is the absence of the dis- * Vesuvius from the period of the colonkation of Italy by the Greeks, until the year 79 after Christ, had betrayed no symptoms 63 turbing forces in our own times and country, any proof that they may not have acted with great intensity in this part of the world at remote periods. Upon this rock Mr. Lyell splits, and here all his contemporaries leave him. Everything, he argues, indicates the constancy and invariability of the operations of Nature. Semper eadem is his motto, applied to her energies. An earth- quake raises the coast of Chili five feet once in a century, four thousand such shocks may have lifted up the Andes, in the short space of four hundred thousand years ! Why should Nature be " prodigal of her efforts and parsimonious of time?" * But to return from this digression. Having briefly examined the operations of existing causes upon the earth's surface, and enquired into the physical events of contemporary and remote periods within the limits of the present state of things events which have hap- pened from the early period, when man and the present species of animals first became tenants of the earth, down to the occurrences recorded in history, or witnessed in our own times, we shall be prepared to enter upon the second and most important division of our subject, the stratified masses, to which we alluded in the outset, as constituting the superstructure of the globe of which indeed all the changes we have hitherto passed in review before us, are only modifications the mere effect, as it were, of time and accident upon the great edifice which of its volcanic character, when after several earthquakes, its fires broke out with tremendous fury, and this celebrated city was in- humed by the ejected matter. * LyelL Principles of Geoloyy. Q 2 64 Nature has reared. In this inquiry, history and tradi- tion cease- to aid us. No longer circumscribed by these, we must push forward into the great ocean of Time, and explore by the light of analogy the new world that lies before us. 65 STRATIFIED ROCKS. OUR observations have hitherto been confined to the earth's surface, we have now to penetrate into its interior, to examine the monuments of past ages which Nature has imbedded in the solid masonry of the vast superstructure of the globe, as if to supply the chrono- logist or historian in after times, with dates and facts for its history, and preserve a record of events which would have been lost in the oblivious stream of time ; in the same manner as in great works of architecture, coins, medals, and inscriptions, are placed in some indestruc- tible portion of the building, in order that posterity may identify the period and circumstances of its erection, should all other records be lost. As we have before seen, Nature has not piled Pelion upon Ossa, or Ossa upon Pelion indiscriminately, as we might from super- ficial observation infer, nor has she reared a rude edifice of unshapen materials like the Cyclopean masonry, but throughout the great fabric of the earth has preserved a symmetrical arrangement and a unity of design ; and in no portion of her work has she omitted to enclose some memorial of the circumstances and events of the period when it was produced. The principal agent employed in the formation of G 3 66 the stratified masses, appears to have been the ocean, or other large bodies of water, in which the materials of the rocky strata have been suspended and quietly de- posited, and the innumerable inhabitants of that element, whose remains form in many cases a considerable por- tion of the consolidated substance, lived and died. But this sedimentary process has not gone on uniformly from the beginning of time : the ocean has not always continued to deposit layer upon layer of earthy matter ; its operations have been interrupted and for a time suspended, and again renewed under different cir- cumstances, by convulsions in the interior of the earth, or changes upon its surface. Thus after a long series of ages, during which it may have deposited an immense mass of calcareous matter, the bed is perhaps upheaved, the sea is dispossessed of its dominion, and land animals and plants flourish on the oozy mass, where shells and fishes had before luxuriated. It is this alternation, this succession of distinct operations, which has produced the series of stratified masses, which it is now our business to examine, and an enquiry attended with more interesting results never occupied the mind of man. For we soon discover that it is not merely the inorganic matter composing the earth's crust which has been remodelled in these geolo- gical changes, but that the animated creation has expe- rienced still greater mutations, many species of animals being entombed in the strata which no longer exist upon the earth. Both sea and land appear to have been peopled with distinct races of inhabitants at successive periods, as every formation contains the remains of organic beings peculiar to itself. These organic relics 67 are not found in the same state as those of a more recent period the elephants' tusks and bones of the diluvial gravel, and the osseous caves, which we have hitherto examined ; but in all cases, the substances, whether animal or vegetable, have undergone petrifaction the most delicate plant, the microscopic shell, and the hardest bone, being alike converted into the material of the rock in which they are preserved. How this meta- morphosis was produced, by what process of transmu- tation the original elements were replaced, atom for atom, by matter in some cases so dissimilar as for instance, vegetable matter converted into silex, or animal sub- stance into sulphuret of iron without destroying or in the least defacing their external configuration, is an interesting inquiry for the chemist, but it appears to be one of those secret operations conducted in Nature's laboratory, which we shall never perfectly understand. It is from these records, engraven upon stone, as it were by the finger of the Deity, that geologists have been enabled to frame a chronology of the earth, to assign certain periods to certain events, to trace the history of organized beings through a countless succession of ages, up to the period when the Omniscient fiat first said " Let there be life upon the earth," to ascend, in fact, the stream of time almost to its source. But in an inquiry so vast, involving a succession of events so complicated and remote, united by insensible gradations, where shall we commence and how measure our progress ? There being throughout the mineral masses a regular order of superposition, and an apparent grada- tion in the fossil organic remains which they contain, indicative of their respective ages, we ought in the 68 highest of the series to find the nearest approach in their organic contents, to the existing animals and vegetables of the countries in which they are situated. Now, were we to examine the hed of the ocean, we should find it filled with shells and other organic re- mains of animals, corresponding precisely with those which now inhabit it ; hut extending our observations to the elevated coast which skirts it, our eastern coast for instance, we discover a similar accumulation of sedimentary matter, (the English crag,) containing a large proportion of fossilized shells of the same species as those now existing in the sea below, but including also others, of which there is no existing types ; and looking further inland, we see rising from beneath the crag another more extensive deposit, formed at an earlier period beneath the ocean, in which the number of shells corresponding with living species is considerably fewer, and as our observations are continued, the analogy ceases altogether, and the existing species entirely dis- appear. With the most recent of these formations, therefore, we commence our inquiry, and go back through these various gradations to the oldest and lowest in the series of fossiliferous rocks. Until a recent period, the newest of the rock for- mations was supposed to be the chalk, but a most in- teresting series of beds, which exhibit, in a remarkable manner, the retrogression in their organic contents to which we have just adverted, is known to geologists as the supracretaceous group, a term recently adopted, which expresses their position supra upon, creta the chalk they being invariably found resting upon that remarkable rock, which, previous to the deposition of 69 these superior beds, appears to have undergone abrasion, and to have been hollowed out into deep valleys or de- pressions in the surface, which these formations now occupy. The supracretaceous beds constitute a large portion of the surface of Europe, and they have been traced with great diligence from the newest to the oldest, from the Subapennine beds on the shores of the Adriatic, where the line of demarcation between the fossil remains and existing species is scarcely visible, to the chalk with its extinct species ; and a sub-classification founded upon their organic contents has been adopted, which is sup- posed to express their relative ages. * To go into a detailed account of this interesting group of stratified masses, even to attempt a bare enumeration of all the localities and remarkable circumstances attending them, would be inconsistent with the design of this " Sketch," in which it is proposed to trace merely an outline of the leading features of geological discovery. * M. Deshayes and Mr. Lyell both suggested, about the same time, this subdivision of the supracretaceous group of rocks : to the former, however, belongs the merit of having most laboriously examined the multitude of shells belonging to these formations, and of having first arranged them in a chronological series. The division, however, adopted, is merely one of convenience, and Mr. Lyell's terms, Eocene, Miocene, and Pliocene are entirely arbitrary, and can never be generally applicable. The circumstances under which distant deposits were effected, must have influenced so con- siderably the character of the animals and plants entombed in them, that any terms expressive of their relative ages founded entirely upon these, are calculated only to deceive, and to defeat rather than to promote the object of geological research. 70 By a remarkable coincidence, the two great capitals of Europe, London and Paris, stand in the centre of two of these supracretaceous formations, and it is to the fortunate circumstance of Paris being so situate, that geology owes its present advanced state. The extraor- dinary discoveries made in the environs of that city by the celebrated Cuvier, and his associate Brongniart^ which first exhibited to the astonished world the forms of animals hitherto unknown to the naturalist, and proved that so remarkable a site, had at former periods been the theatre of successive revolutions, both in the animal and mineral kingdoms, formed an era in geology, and gave a new impulse, not only to this, but to the other natural sciences, everywhere an intense desire being excited to become acquainted with the phenomena and causes of these strange mutations. As the formations in the Paris basin as it is termed, have been, from this circumstance, more accurately examined than in any other locality of similar extent, we will take them as a model of the strata under consideration ; but it must not be from hence inferred, that the supracretaceous rocks, which form, perhaps, three-fourths of the surface of Europe, are in every instance piled upon each other, in conformity with this model of a district containing only a few hundreds of square miles. There is, however, a remarkable coincidence everywhere observed in the leading features the alternations of marine and fresh- water productions which characterize these formations, however distant the locality, or dissimilar the circum- stances under which they have been produced. * * It appears from recent descriptions of the great mountain chain of Caucasus, by Klaproth and Kupfer, that supracretaceous 71 The minute and accurate examination which the country surrounding Paris has undergone, has led to the dis- covery that an area of ninety miles in diameter, of which that city is the centre, has been at different periods occupied alternately by the sea, and fresh- water lakes or large rivers, whose successive deposits have formed an accumulation of distinct beds of earthy matter several hundred feet in thickness, in each of which indelible traces of the causes by which they were produced may be observed on the one hand, the sea entombed in immense profusion the remains of the shelly inhabitants with which it was peopled ; on the other, the fresh- water enclosed in its sedimentary beds riot only its peculiar shells and aquatic tribes, but relics of the strange quadrupeds which frequented its margin, and were accidentally drowned or overwhelmed by inundations, together with specimens of the vegetation of the period the trees and plants which grew upon the dry land in its vicinity. Thrice was the sea quietly but effectually displaced by fresh water, during the long interval in which these deposits were accumulating, and at each successive period a decided change in the inhabitants of both sea and land is discernible, indicative, -in the main, of that approach to existing species to which we have rocks (of which the youngest contain shells of species actually existing in Lake Aral and the Caspian sea,) approach to the foot of that lofty ridge of mountains, and being elevated by it, attain a height of two thousand five hundred feet ! They alternate with fluviatile beds (deposits from rivers,) even at that elevation, and repose as elsewhere upon a chalk formation, which in its turn covers the oolitic series skirting the older rocks, precisely as we might have inferred from the analogy of the English strata. before alluded. The subjoined diagram will aid the description of these remarkable alternations, and it will also illustrate the violent denudation (stripping) which these beds, in common with all the solid strata of the globe, have undergone since their original formation. It is by these natural excavations that we get an insight into the superposition of mineral masses, which would otherwise be concealed from our view, and obtain access to rocks, for building and other useful purposes, which, but for this denudation, would be inaccessible. Thus the city of Paris, although in the very heart of the basin, where we should find the greatest accumulation of these supracretaceous beds, stands upon one of the lowest rocks of the series, the calcaire grossier, in which those singular excavations, the catacombs, have been made for the stone of which the city is built. But in the hill of Montmartre and on the opposite side of the denuded valley through which the Seine now flows, we discover the whole series piled upon each other in their proper order of succession, and corresponding so exactly with each other in position, character, and thickness, that they must have been, originally, continuous across the intermediate valley; which, however, the section will make more obvious than any explanation. Chalk Now if we trace these beds in the order in which they rest upon each other, commencing at the chalk, which we shall hereafter consider, and ascending to the 73 surface, we find reposing upon that rock and filling up the irregularities upon its surface, a bed of clay ( 1 ) of variable thickness, termed plastic, from the circumstance of its readily retaining the forms impressed upon it, which was evidently formed beneath a freshwater lake, or in the estuary of a large river, from the great accu- mulation of vegetable remains, with shells peculiar to freshwater, preserved in its substance. These relics of vegetation consist either of impressions of the branches, stems, and leaves of trees or plants, moulded in the inflexible material which envelopes them, or of a mass of these converted into carbonaceous matter, in which the vegetable structure is obliterated, arranged in layers of earthy coal (lignite) jet, and even pure coal ; but it may be observed, that there is no similarity of character in these vegetable productions and those found in the regular coal-formations, which belong to a widely-distinct period. The bones of amphibious reptiles are found associated with these productions of the land, but no remains of land animals and mammifera.* It appears from recent discoveries, that in the upper portion of this bed of plastic clay in some situations, sea shells are found in- termixed with freshwater shells and drifted wood, from which it has been inferred that it was deposited at the entrance of a large river into the sea, in the same manner as wood and other land-productions may be drifted down the Mississippi, and mixed with sea-shells in the bed of the Gulf of Mexico. To the plastic clay succeeds the calcaire grassier, * Mnmmifera animals which suckle their young, from mamma breast, and/ero, to bear. H 74 (2 in the section,) a coarse limestone of great thickness, in which myriads of marine remains are entombed, which appears to have been quietly deposited during the long period which the sea must have rested over this district. The most remarkable feature of this formation is its divi- sion into layers of distinct earthy matter, like courses of masonry in a building, which present, wherever they are examined, not only their peculiar fossil contents, but a uniform thickness, although this may, in many cases r amount only to a few inches. This extraordinary regu- larity of formation indicates that they were deposited in a tranquil sea, while, on the other hand, the comminuted and triturated state of many of the shells, might lead us to infer that they had been exposed to the action of agitated waters. Eight hundred species of shells, few of which correspond with any now existing, have been exhumed from the beds of the calcaire grossier, * and a regular * Mr, Lyell mentions the circumstance of the great pre- dominance in this limestone of shells referrible to the genus cerithium a testaceous shell, which is known to inhabit the sea near the mouths of rivers where the waters are brackish as affording strong evidence in favour of his hypothesis, that the vegetable deposits in the inferior formation, as well as those occasionally found in the one under consideration, were brought down by the currents of rivers which flowed into the gulf or bay, in the bottom of which this calcareous bed was formed. But wherever they may have been deposited, whether in the bed of rivers or of a fresh- water lake, it is clear that such prodigious accumulations of vegetable matter, could only have been effected gradually, and their uniformity over a large area, and their alter- nation with other distinct masses, can hardly be attributed to the accidental drifting of wood by rivers. For instance, although the Mississippi may annually bring down an immense quantity of tree& 75 gradation, not only in their character, but in their quantity, is observable as we proceed upwards, the upper layers being almost destitute of fossils, as if the waters, beneath which they were deposited, no longer contained shell-fish, or had ceased to preserve them. Passing over a thin silicious stratum with marine remains, we arrive at the celebrated gypsum beds, (marked 3 in the section,) and here an exhaustless field of interest opens upon our view. In these strata, which consist of alternate layers of gypsum, marl, and lime- stone, there are buried innumerable bones of unknown quadrupeds, birds, tortoises, crocodiles, and insects, mixed with shells and fishes of freshwater species, proving that the sea, after a long period, had again abandoned the basin, and left it occupied by a lake or morass ; or that the waters of a river had driven back the ocean and its briny tenants. * A change in the nature of the and vegetable matter, of which it has despoiled the country in its course, it would not systematically spread them in the Gulf of Mexico, or in its estuary, so as to form a continuous stratum to be immediately covered up by the sediment from the ocean, but their deposit would of necessity be accidental, and entirely for- tuitous, dependent upon the depth of water, the force of currents, and the relative buoyancy of the transported matter. Alternate effects must have been produced by alternate causes. *M. Prevost, whom Mr. Lyell quotes and confirms, states, that in some situations these gypseous beds alternate with some of the upper strata of the inferior formation, the calcaire grossier, and that the gypsum is most fully developed in the centre of the basin, and from hence argues, that while the sea was forming its cal- careous beds in other directions, a river, holding this sulphate of lime in solution, was here depositing the gypsum and the land productions which were floated down its stream. It proves unques- tionably that the transition was not so sudden and complete as H 2 78 between the horse and the tapir, with the small stupid eye of the hog. Seven species have been described by Cuvier. It has been found in the Isle of Wight, and in many more recent formations, but never in the caves or in diluvial gravel. It is one of those species that had ceased to exist before the appearance of man upon the earth. The animal remains are not more strange than those of the vegetable kingdom associated with them, for these all belong to species peculiar to tropical climates. During the accumulation of this deposit, a great extent of dry land must have existed in the neighbour- hood, but this was destined to be again overwhelmed, the sea suddenly resumed its dominion, reoccupied the place of the fresh- water lake or river, and left beneath its waters a mass of micaceous sand, (4 in the diagram) eighty feet in thickness, filled exclusively with the peculiar remains of the shelly tribe of animals which at this period inhabited the ocean. Again, for the last time, the briny element retreated, a lake took possession of its vacated bed, in which the animals and plants living upon its banks were submerged ; its shallow waters were gradually dried up, and its marshy bed (5) * now forms the summit of many of the vine- clad * The prevalence of a species of plant called by botanists charce, or water-loving plants, in this formation, has been with great probability suggested, as indicating that the water which at this period succeeded the ocean, existed in the state of marshy or shallow lakes, such as now overspread the flat lands in the delta of a large river, or a lake which has been partially silted up ; as these plants are always found in such situations ; and the animal remains also are such as coincide with this supposition. 79 hills of that fertile country, where, apparently secure from a renewal of the " war of elements," in which myriads of individuals and whole races of animals have been annihilated, man now pursues the peaceful occu- pations of industry, interrupted only by the revolutions of society, the convulsions of passion, and the con- tentions of party, the destructive and frightful operations of which this eventful region has also been the theatre. The same succession of events which produced the series of rocks we have been examining, in France, occurred perhaps at the same geological period in this country, where, however, the mineralogical character and thickness of the masses is so distinct as almost to defy recognition. It is their position in isolated basins formed in the chalk, and the similarity of fossil organic contents, which prove their identity. No remains of mam- malia are found in the London clay, (although in the cor- responding formation in the Isle of Wight they have lately been observed) , but skeletons of amphibious reptiles have been discovered, and in a detached portion of this bed, the Isle of Sheppey, at the mouth of the Thames, plants, fruit of the cocoa-nut species, and spices of tropical cli- mates exist in great profusion. Great commotions and convulsions appear to have aflected the surface of this part of the earth, soon after the deposition of the tertiary* beds, which have upheaved or * Tertiary is the term usually applied by geologists to the aupracretaceous formations, Dut there seems so much impropriety in the use of a term which expresses neither the age nor the position in the series of this important group of rocks, that I have ven- tured, for the reasons before stated, to adopt, generally, the more approved term, supracretaoeous. 78 between the horse and the tapir, with the small stupid eye of the hog. Seven species have been described by Cuvier. It has been found in the Isle of Wight, and in many more recent formations, but never in the caves or in diluvial gravel. It is one of those species that had ceased to exist before the appearance of man upon the earth. The animal remains are not more strange than those of the vegetable kingdom associated with them, for these all belong to species peculiar to tropical climates. During the accumulation of this deposit, a great extent of dry land must have existed in the neighbour- hood, but this was destined to be again overwhelmed, the sea suddenly resumed its dominion, reoccupied the place of the fresh- water lake or river, and left beneath its waters a mass of micaceous sand, (4 in the diagram) eighty feet in thickness, filled exclusively with the peculiar remains of the shelly tribe of animals which at this period inhabited the ocean. Again, for the last time, the briny element retreated, a lake took possession of its vacated bed, in which the animals and plants living upon its banks were submerged ; its shallow waters were gradually dried up, and its marshy bed (5) * now forms the summit of many of the vine- clad * The prevalence of a species of plant called by botanists charce, or water-loving plants, in this formation, has been with great probability suggested, as indicating that the water which at this period succeeded the ocean, existed in the state of marshy or shallow lakes, such as now overspread the flat lands in the delta of a large river, or a lake which has been partially silted up ; as these plants are always found in such situations ; and the animal remains also are such as coincide with this supposition. 79 hills of that fertile country, where, apparently secure from a renewal of the " war of elements," in which myriads of individuals and whole races of animals have been annihilated, man now pursues the peaceful occu- pations of industry, interrupted only hy the revolutions of society, the convulsions of passion, and the con- tentions of party, the destructive and frightful operations of which this eventful region has also been the theatre. The same succession of events which produced the series of rocks we have been examining, in France, occurred perhaps at the same geological period in this country, where, however, the mineralogical character and thickness of the masses is so distinct as almost to defy recognition. It is their position in isolated basins formed in the chalk, and the similarity of fossil organic contents, which prove their identity. No remains of mam- malia are found in the London clay, (although in the cor- responding formation in the Isle of Wight they have lately been observed) , but skeletons of amphibious reptiles have been discovered, and in a detached portion of this bed, the Isle of Sheppey, at the mouth of the Thames, plants, fruit of the cocoa-nut species, and spices of tropical cli- mates exist in great profusion. Great commotions and convulsions appear to have affected the surface of this part of the earth, soon after the deposition of the tertiary* beds, which have upheaved or * Tertiary is the term usually applied by geologists to the supracretaceous formations, out there seems so much impropriety in the use of a term which expresses neither the age nor the position in the series of this important group of rocks, that I have ven- tured, for the reasons before stated, to adopt, generally, the more approved term, supracretaceous. 80 depressed them in common with the lower rocks ; thus, the now insulated basins of London and the Isle of Wight appear to have been originally continuous, but have been separated by the elevation of the intervening chalk hills, from which the upper formations have been subsequently washed away by the violent agency which scooped out our valleys : and the occurrence of the lower members of this series capping the older summits of hills in the west and other parts of England, precisely as they are found in the country intervening between London and the Isle of Wight, seems to indicate that they originally extended far beyond their present circumscribed limits. The general inference from all the facts connected with the supracretaceous rocks, is, that Europe at the period of their formation was partially covered with extensive lakes, into which the sea made occasional inroads, and from alterations in the surface effected by internal commotions, which were then frequent, was repeatedly admitted and excluded, while rivers emptying their waters into these great reservoirs, aided in accumulating the debris of land animals and plants. Some of these lakes continued to exist until a very late period in geological history, and the outlets by which they were drained and laid dry still remain : as for instance, at the mountain gorge of the Fortl'Ecluse, through which the Rhone now escapes from Switzerland ; and the narrow pass of the Rhine at Bingen, previous to the forcing of which the waters of these Alpine rivers overspread a large expanse of country, in the superficial strata of which evident traces of their long and tranquil sojourn- men t may be observed. As we failed to identify the remains of the human 81 species with the caverned bones and relics buried in the diluvial and other beds, which belong to the most recent of geological periods, their entire absence in the solid strata will create no surprise. But when all the pheno- mena of fossil remains, whether dispersed on the surface or imbedded in rocks, were referred to the deluge, naturalists experienced great disappointment at not finding the bones of man associated with those of the animals which they regarded as his contemporaries : it was an anomaly which, prolific as was their age in theory, they were utterly unable to explain. Judge then of the satisfaction with which the announcement of Scheuchzer, of the discovery of a human skeleton im- bedded in the limestone of (Eningen, * was hailed by these enthusiastic theorists. Their hypothesis was no longer questionable, scepticism must hide its diminished head before this " preuve indubitable" Scheuchzer described it in a learned dissertation in the " Philo- sophical Transactions" for 1 726, entitled "Homo diluvii testis" or the man who witnessed the deluge, accompanied by an engraving on wood on the natural scale ; (the sketch in the margin is, however, copied from Cuvier's drawing.) And again, in a subse- quent work, the " Physique Sa- cree," he introduces the portrait and description, and assures us " that it is indubitable and that it contains the moiety of the * The rock of Oil iiingeu in which these remains were found, is a lacustrine formation of recent date, highly prolific in organic 82 skeleton of a man that even the substance of the bones, and what is more, the flesh, and parts still softer than flesh, are incorporated in the stone ; in fact, that it is one of the rarest relics that we can possess of the de- voted race which perished at the flood !" * What must have been the state of science when a philosopher and an eminent physician knew so little of comparative anatomy ? when the scientific world could be persuaded to believe that an arrangement of bones so dissimilar, resembled the human form ? Our astonishment at the crudities and absurdities of the early theories of the earth ceases, when we regard the extraordinary ignorance which then prevailed. But how great had been the progress of comparative anatomy, and with what rapid strides it must have marched, when Cuvier could deduce from a single bone the form and species of the entire animal ! Scheuchzer's imposture, however, did not long continue, it was soon discovered that this was the skeleton of an individual of some other " racemaudite" relics of animals and plants ; which are said to be of species belonging to a climate approximating to that of Europe at the present day, while in older deposits they are referrible exclusively to tropical species. The Rhine has cut a passage through this rock since its deposition. * The deception might not have been originally so palpable, as the collateral parts of the skeleton were not developed until Cuvier, at the request of the director of the museum at Haarlem, in 181 1, examined and chisseled away the stone, where from the model of a living species he expected to find other bones a process which must have been singularly gratifying to the Baron, as hitherto concealed portions rose up as it were beneath his chisel, in accord- ance with his expectations, and in conformity with the model of the species of animal to which he had at first glance referred it. 83 and eventually the " man who saw the deluge" was proved by Cuvier to be an aquatic salamander. But this is not the only mistake into which philo- sophers have fallen, in their eagerness to discover some traces of the antediluvian population. Two real skele- tons of human beings, discovered in a solid rock on the shores of the island of Guadaloupe, a few years ago, were for some time regarded as unequivocal remains of the unfortunate contemporaries of Noah ; and to this day hundreds of those who view the well-known fossil skeleton in the British Museum, for want of better information, regard it as a genuine homo dilumi testis. But even this inference, sanctioned as it appears to be by probability, was too hasty, and is now abandoned by geologists. A careful examination of the spot where they were discovered, proves that the mass of rock which enclosed them is of very recent origin, and in fact, is still accumulating, being merely a bank raised by the sea at the foot of a slope on the shores of the island, and formed of sand, shells, coral, and other matter thrown p by the waves, and solidified in the manner of stalactites* and travertin, which we described among the effects of the existing operations of nature, so that in all probability these ancient relics, are merely the encrusted bones of some shipwrecked mariners of this or the preceding century. It is impossible to infer the age of any of these sedimentary rocks from their mineral character, the most recent and even contem- porary deposits, as we have seen, being sometimes as completely indurated as the most ancient marbles. * Solid matter deposited from water holding lime in solution. Among the extinct animals which modern research has brought to light, the megatherium, from mega great, and therion wild beast, is the most remarkable for its colossal size and extraordinary proportions. It may not, perhaps, strictly belong to the period under con- sideration, and indeed the general inference is, that it existed subsequently to the extinction of the palaeothe- rium, and the other strange quadrupeds buried in the supracretaceous rocks of Europe, but it is too remarkable a character to be omitted in our retrospect of the early inhabitants of the earth, and is, moreover, deserving of attention from the interesting inferences to be adduced from its peculiar organization. Only two individuals of this species of animal have been discovered, but from the fortunate circumstance of one having been found almost entire, naturalists have been able to investigate its structure with more precision than that of many others, whose remains, though existing in greater abun- dance, are generally dispersed. The discovery of this interesting skeleton was entirely accidental. A peasant passing along the river Solado, near Bueftos Ayres, threw his lasso at something which stood half-concealed in the stream, and dragged on shore the enormous pelvis of the animal. This led to a further search, the river was diverted from its course by means of a dam for that purpose, and the rest of the bones with the teeth and claws, imbedded in a stratum of blue clay, through which the river had cut its channel, were soon brought to light and transferred to Madrid, where, the several portions having been carefully put together and the animal anatom- ically re-constructed, this " mighty pre- Adamite" now forms the most remarkable feature of the royal museum. 85 The megatherium, although of such gigantic dimen- sions, is considered to have been a species of sloth, with a maily covering like the armadillo. Cuvier calls it the "paresseux yeant" and inferred from its organiza- tion, that like the sloth it fed upon vegetables, but while the one lived upon leaves the other fed upon roots. Buffon and other naturalists have regarded the organiza- tion of these animals as imperfect, and considered them clumsy performances of nature, in which the inconveni- ences resulting from deformity were attended with no compensating advantages. Professor JBuckland, in a recent lecture, has shewn the absurdity of this inference, and proved by an admirable train of inferential reasoning, deducing the habits of the extinct animal from its organ- ization, that so far from their being abortions, they are beautiful instances of that richness of contrivance by which all organized beings are adapted to the circum- stances in which they are placed, and the part they are destined to perform in the creation. The peculiarities of the sloth, although they unfit it for moving with ease upon the earth, admirably adapt it for its destined resi- dence upon the branches of trees ; so the proportions of the megatherium, apparently so anomalous, are exqui- sitely arranged with a view to its intended subsistence upon those tubercular roots which abound in the countries where its remains were found, and which, from the construction of its grinders, it is inferred, were the food of this animal. " Its teeth," says Dr. Buckland, " though ill-adapted for the mastication of flesh or grass, are wonderfully contrived for the crushing of roots, with the further advantage of keeping themselves sharp- set in the very act of performing their work." i An idea may be formed of the outline and general proportions of the megatherium, from the subjoined sketch, copied from Cuvier's very accurate drawing. The animal was about twelve feet long and eight high. The fore feet, nearly a yard in length and exceed- ing a foot in breadth, were armed with three enormous claws, each more than a foot long, which it is supposed to have constantly employed in scraping roots from the ground, while the weight of its ponderous body rested firmly upon its hinder extremities the anterior part of the skeleton, it will be perceived, is light and elegant compared with the posterior proportions, which are said to exceed in bulk those of the largest elephant. To this incongruous mass of bones was added a coat of mail, which it is suggested was to protect the animal from the annoyance which the sand and dirt raised in digging for its food would occasion,* or it might have been intended to render the animal invulnerable to all external attacks, whether from venomous insects, to which, in the tropical climates where it existed, it would be exposed, or from * The armadillos which obtain their food by digging in this manner, are also covered with a maily skin. 87 beasts of prey, with whom, notwithstanding its colos- sal size, it was ill-prepared to contend. Considerations such as these, exhibit in a new and stronger light the beautiful harmony and unity of design which pervades the creation, and gives geology a new claim upon the philosopher and theologian. Thus, while astronomy proves to us that the ponderous orb which hangs in mysterious equilibrium in our system, and the stupendous worlds, which, with the great globe itself, whirl with inconceivable force and never- failing regu- larity around it, are acted upon and governed by the same laws as those which regulate the apparently capri- cious motions of the smallest atom which dances in the sunbeam, geology shews us that the same wise contri- vance and skill, which characterize the structure of the animated being of to-day, is stamped upon the organic relics of the remotest period of the past. But, reserving for the future these reflections, we must proceed in our examination of the stratified masses, in which new won- ders and new objects of admiration will present them- selves as we advance. The supracretaceous rocks, which have perhaps occupied a larger share of attention than is com- mensurate with their relative importance, or compatible with the plan of this sketch, rest invariably upon that well-known rock-formation the chalk, an imper- fect limestone, distinct alike in its mineral character and fossil contents. The chalk-hills are a remarkable feature in this country, which appear to be the result of a general upheaving of this, * in common with the * The chalkis almost emblematic of sterility, for, although an enriching manure when combined with strong aluminous soils, i 2 88 lower strata, the general line of bearing of which through- out this island is from N. E. to S. W. " This/' says Mr. Conybeare, " may have been effected, not by a single, sudden, or violent convulsion, but by a gradual, gentle, and protracted upheaving, continued without interruption during the whole period of the formation of all these strata." Although this is generally true, there are in some situations decided marks of violent derangement : for instance, in the Isle of Wight, where the chalk, which must have been originally horizontal, with all its in- cumbent sedimentary beds of lacustrine and marine origin, similar to those in the Paris basin, have been forced into a vertical position. * The chalk is entirely where it exists in excess, it is universally attended with barrenness, and is generally characterized Dy a peculiar stunted vegetation. It is to this latter circumstance, according to an eminent geologist, that the origin of the singular custom of the " Chiltern hundreds," the fiction by which Members of Parliament vacate their seats, may be traced. It appears that the Chiltern Hills, a remarkable part of the chalk range in Oxfordshire, were formerly covered with brushwood and thickets, which harboured banditti, whose depre- dations became so alarming that it was found necessary to institute a permanent local force, for the protection of the lives and property of his Majesty's faithful lieges, over which force presided an officer, appointed by the crown, with the title of Steward of the Chiltern Hundreds. His " occupation" being long since " gone" the office has become a nominal one, the acceptation of which, however, is sufficient to incapacitate a Member from holding his seat in the House of Commons. * Mr. Conybeare has recently made . some interesting obser- vations upon the general lines of disturbance traceable in the chalk formations. He observes that there is a general tendency to 89 of oceanic origin, and the manner in which its multitu- dinous organic relics are preserved, is one of the most remarkable features of the fossiliferous rocks. The most fragile substances, such as sea- weeds and sponges, retain their forms ; fish are sometimes found not only with their bodies uncrushed by the enormous super- incumbent pressure, but in some cases with their fins expanded as if in the act of swimming ; * shells of the most delicate construction are seen precisely in the same state as when inhabited, the animal only being displaced by carbonate of lime, even the colour of these is sometimes beautifully preserved. A thousand species of shells and other organized beings have been disentombed from this vast deposit, nearly the whole of them are inhabitants of the ocean, and very few correspond with any now existing, and not only do they differ entirely from existing races, but almost as widely from the fossil parallelism between its main line of elevation and the earlier and more violent convulsions which have effected the previously-formed strata, such as those in the coal-formation, before the deposit of the new red-sandstone which covers it : this general line subsists only in the central parts of England, in the south and north there are others bearing in an opposite direction, but exhibiting the same parallelism to the disturbances in the older strata. See Conybeares Geological Report to the British Association. Mr. Elie de Beaumont's theory is, that all the lines of distur- bance of the strata assignable to the same age are parrallel. * Mr. De La Beche describes specimens of this kind which were exhibited to the Geological Society by Mr. Mantell, and observes, that they differ thus far from fossil fish usually discovered, the fins of which are almost always compressed. Researches in Theoretical Geology. i 3 90 remains of the more recent the supracretaceous rocks. Many new genera are for the first time met with in the chalk, such as the belemnite* (fig. 1), and the ammonite (fig. 2) , of which a great 2 variety existed at this period. In fact there are no species of shells common to the secon- dary and tertiary rocks , and Mr. Agassiz, who has devoted years of study to this particular department of natural history, states, that out of five hundred spe- cies of fossil fish which he examined, he did not find one that he could refer to both formations. The chalk was evidently deposited in the bed of a tranquil sea, from which the greater part of Europe, and indeed of other continents, f have since emerged : * Belemnite, from belemnon a dart, an extinct genus of animals called cephalopoda, (cephale head, and poda feet,) so called from the organs of motion being arranged round the head. Ammonite is derived from the resemblance of this shell to the horns on the statues of Jupiter Ammon. It is also an extinct genus of cephalopoda, of which numerous species are found fossil, in this and the older formations. f The chalk has been observed in Patagonia, near the Straits of Magellan, and an extensive deposit corresponding not in appearance but in its fossil remains and position, is known to exist in North America, and it is an interesting fact, that the exuviae of enormous extinct animals of the saurian tribe, of precisely the same species as those found in the lower sand of this formation in Sussex, have been discovered in the ferruginous sand, an analogous deposition, in America, from which it might be inferred, either that the great gulf, the Atlantic, did not at this period exist, or that remote countries were peopled with the same races of animals. 91 but we have also evidence in the lower members of the chalk-formation, * that dry land existed at the period of, and anterior to their deposition ; for we find inter- posed between the subjacent beds in the Isle of Wight, and other places, a bed of black vegetable mould, full of the stems of trees of the palm and fir tribe, fcycadce and conifer cej sometimes erect, like the trees in the submarine forests, f with their roots fixed upon the Portland limestone, and in the beds which succeed, the green sands of the chalk-formation, specimens of wood are found pierced by the teredo, (a species of sea- shell before alluded to, which bores into hard sub- stances) as if they had been tossed about for a long period in the ocean beneath which they were imbedded. Those singular concretions, flints, are peculiar to the chalk-formation, and many ingenious speculations as to their origin have, from time to time, appeared. Flints, it is well known, are composed of silex, a sub- stance totally unlike the chalk, a carbonate of lime, in which they are imbedded, and they usually exist in layers, in many cases corresponding with the inclination of the beds of chalk, from which the general inference was, that they were deposited by mechanical means in * These are known to Geologists by the terms Upper and Lower green sands, and to travellers as they are seen in the deep section, through which the road passes at Woburn. f The only difference in the trees in the dirt-bed, as this black vegetable stratum is termed, and those of the submarine forests, would appear to consist in the tropical nature of those in the dirt- bed, and the near approach, if not the identity of the submarine trees, with those now existing in Great Britain and France. De In Heche's GeoL Manual. 92 the same manner as all other sedimentary strata, hut a recent discovery of Mr. Babbage, (the inventor of the calculating machine,) seems to prove, what had been before suggested, that they are the effect of chemical precipitation. In the preparation of the materials for the manufacture of porcelain, clay and burnt flints ground into powder are mixed together in certain pro- portions, and suspended in water, from which a deposit is formed, containing the materials united in their proper proportions for the manufacture. It then appears an homogeneous mass, so intimately are the substances blended together, but ifit.be allowed to stand any con- siderable time, the silex separates, and forms small nodular concretions which render it unfit for use. In this manner, it is suggested, the flint nodules were formed in the chalk, the silicious matter being suspended with the lime in water in a state of semi-fluidity, and having no affinity for carbonic acid, with which the lime united, would naturally separate, and as the mass con- tinued to accumulate the operation would be repeated, and layers of flints would be formed precisely as we find them. On the continent of Europe the chalk rises into lofty mountains, and instead of the white imperfect limestone of this country, it there sometimes assumes the form of a dark granular marble, easily identified, however, by means of its fossil organic contents ; and even in this country, and in Ireland, wherever there are symptoms of violent disturbance from the injection of basaltic matter, or other igneous action, this altered character is observable. * *.. This circumstance is one of the strongest proofs of the igneous origin of basalt, and what are called trap -rocks : not only 93 During the period of the deposition of the chalk, a deep sea covered the whole of the extensive area which it occupies, but a great extent of dry land as we have seen, had previously existed, whose shores the ocean's surge had long continued to lash. Into this ocean poured vast rivers, and inland lakes discharged their swoln waters. A Niger or a Mississippi, draining the north of Europe, * of which England was then an in- tegral portion, or perhaps a continent over which the Atlantic now rolls, had its estuary in the Wealds of Sussex, where an extensive accumulation of sand, lime- stone, and clay, was formed, in which the inhabitants of its brackish waters, and of its banks, with other spoils of the land brought down by the current, were commingled. This formation is known to geologists as the Wealden rocks. Although not of numerous species, the organic the chalk, but all the other rocks are more or less crystallized, when in contact with these veins or dykes : and Sir James Hall produced the same result in his celebrated experiments upon the effect of heat under pressure. Carbonate of lime, when exposed to great heat, under sufficient pressure, does not part with its car- bonic acid as it does in the common process of burning lime in the open air, but fuses, and its particles, thus moving freely among themselves, assume a crystalline arrangement. * Dr. Fitton, in his Geological Sketch of the Vicinity of Hastings, suggests, that the corresponding formation of the Bou- lonnois and the Pays de Bray, in France, were formed at the same period as the Wealden rocks of Sussex, hence this was the direction of the river's channel. Supposing them to have been continuous and formed in the estuary of a river, the area would not be greater than that covered by the delta of the Niger. 94 exuviae of the Wealden rocks are rare and remarkable. A huge reptile resembling the Iguana of South America, hence termed the Iguanodon, four times the size of the largest crocodile, armed with teeth set in enormous jaws, and crested with horns, * roamed on the shores of the river or inland water alluded to, with associates no less hideous, the Hylaesaurus, the Megalosaurus, and the Plesiosaurus, all of genera which have long since ceased to exist upon the earth beings whose forms rival the fantastic creations of ancient mythology. Crocodiles and tortoises, and other amphibious animals, were also numerous, but amid all the spoils of the land, of trees and a luxuriant vegetation, which are here accumulated in such abundance, no remains of mammalia, or the higher orders of animals have ever been discovered. It will be remembered that we last saw these in the upper beds of the supracretaceous rocks : the chalk-formation ap- pears to form a " wall of partition" in the organic cre- ation, on passing which we enter, as it were, upon a new scene of existence ; all the recent tenants of terra- firma have vanished, and the imagination is startled at the monsters, which, at the bidding of science, spring up from the vasty deep. Reptiles of gigantic stature at this period, and for a long time anterior, seem to have had undisputed possession of the marshy plains and woody hills which then rose above the waters ; but these, like their successors, became extinguished in the subse- quent revolutions which the surface of the globe expe- rienced. * See Mantell's description of this monster, in Phil. Trans. 1825, and Illustrations of Tilgate forest, 1827. 95 The Wealden rocks, it will be obvious, from the origin assigned to them, were a local deposit. The next in the geological series is the Oolitic group, a term applied to it from the circumstance of one of its most remarkable rocks being composed of small globu- lar particles, resembling the roe or eggs of a fish, from oon, the Greek word for egg, and lithos, stone ; the term is not applicable to the character of the beds generally, but, like other terms in geology, is merely one of con- venience. The oolite deposits are of great extent in this country, and throughout the continent of Europe, where they are known as the Jura limestone ; the Jura mountains being a remarkable portion of this formation. In England its various beds occupy a considerable por- tion of the surface, extending in continuous bands from Devonshire to the mouth of the Tees. Their minera- logical character is very various, * and each has its peculiar term assigned to it ; but all appear to be com- posed of finely-comminuted matter, arranged in parallel layers: hence, and from the circumstance of shells, such as those which inhabit shallow waters, being abundant, it has been inferred that they were deposited in a tranquil and shallow sea ; and, as in the beds beneath the chalk we saw that terrestrial animals and plants were buried, so, in the lower beds of the oolite, there are abundant * Not only is their mineralogical character different, but the organic contents of the same formation in the northern and southern parts of England are for the most part distinct This is not sur- prising; the bed of the German ocean at the mouth of the Tay, would, if laid bare, be found to differ very widely from the bed of the Nore, both in the character of the sedimentary matter and the imbedded shells. 96 relics of the dry land, which existed in the vicinity of the sea at the period of the formation of these sedi- mentary beds, where the vegetable remains in some cases, as in Yorkshire, are accumulated in such abund- ance as to form coal-strata, of an imperfect kind, but of sufficient value to pay for working. * * The similarity of appearance between many of the lower beds of the oolitic group, particularly the lias clays, and the strata generally accompanying coal, and the local accumulations of car- bonaceous matter frequently found within the lias range, upon and beneath the surface, have led to many abortive attempts to procure coal in the midland counties of England. These searches have been generally commenced in entire ignorance of geological principles, and of course have terminated in disappointment and loss. In Leicestershire and Nottinghamshire, where the lias beds are strongly developed, many such experiments have from time to time been made. At the foot of the escarpment of the great oolite at Billesdon in Leicestershire, an attempt has been recently made to reach the regular coal-formation, the outcrop of which it is said may be seen in an adjacent valley. Six hundred feet of the strata, however, were penetrated, but nothing but indications of the coal were discovered, and among these indications fossil fruits are men- tioned ! The interposition of the primitive rocks of Charnwood Forest, which appear to have formed the eastern limit of the Leicestershire coal-basin, render hopeless the chance of discovering coal beyond the line of that remarkable range. The coal-strata invariably rise upon their approach to these hills ; and even the subjacent bed, the limestone, upon which they rest, is sometimes thrown up to the surface, as at Gracedieu, where it is seen resting on the flanks of the porphyritic rocks of Whitwick. The circum- stance on which the hopes of success at Billesdon were built, when the coal-strata which it was thought were traceable at the surface, had eluded detection, was, that the regular coal-formation might have been brought near to the surface hi this situation, by the up- heaving of the Forest rocks and the circumjacent beds ; but it should 97 The vegetable remains thus accumulated are quite dissimilar to those which we shall hereafter find con- stituting the coal-formation. An entirely new and distinct vegetation seems, at the period under considera- tion, to have clothed this portion of our planet, and plants analogous to those now flourishing at the Cape of Good Hope, and in New Holland, appear to have been common. It would far exceed our limits to describe each of the various formations of which this group is composed. The Lias, the lowest member of the series, is, however, peculiarly entitled to consideration, on account of its organic riches. It is highly prolific in animal remains, have been remembered, that the elevation of these rocks took place long anterior to the formation of the superior beds the lias, on which the experiment was commenced, and the red-marl, upon which the lias rests ; for even the red-marl, a much older deposit than the lias, and by which the coal- formation is covered up, rests everywhere undisturbed upon the almost vertical beds of the primitive rocks, and the lias limestone, the lowest bed in the series of the lias, has obviously undergone no considerable derange- ment. In a Sketch intended merely to exhibit the great physical commotions which have affected the surface of the earth, it would be foreign to my object to enter into the details of a question of practical geology ; and Professor Sedgwick and others have already pronounced their opinion upon this and similar projects : but it may be well to observe, that in any experiment of this nature, where the geographical position is equivocal, a ready and infallible test is always to be found in the distinct character of the vegetable fossils. Ferns, it is true, are common both to the oolitic group and the coal-formation, but the gigantic calamites and palms which characterize the latter, are entirely absent in the former. SecLindley and Hmtturis Fossil Flora, preface, vol. 1. E 96 relics of the dry land, which existed in the vicinity of the sea at the period of the formation of these sedi- mentary beds, where the vegetable remains in some cases, as in Yorkshire, are accumulated in such abund- ance as to form coal-strata, of an imperfect kind, but of sufficient value to pay for working. * * The similarity of appearance between many of the lower beds of the oolitic group, particularly the lias clays, and the strata generally accompanying coal, and the local accumulations of car- bonaceous matter frequently found within the lias range, upon and beneath the surface, have led to many abortive attempts to procure coal in the midland counties of England. These searches have been generally commenced in entire ignorance of geological principles, and of course have terminated in disappointment and loss. In Leicestershire and Nottinghamshire, where the lias beds are strongly developed, many such experiments have from time to time been made. At the foot of the escarpment of the great oolite at Billesdon hi Leicestershire, an attempt has been recently made to reach the regular coal-formation, the outcrop of which it is said may be seen in an adjacent valley. Six hundred feet of the strata, however, were penetrated, but nothing but indications of the coal were discovered, and among these indications fossil fruits are men- tioned ! The interposition of the primitive rocks of Charnwood Forest, which appear to have formed the eastern limit of the Leicestershire coal-basin, render hopeless the chance of discovering coal beyond the line of that remarkable range. The coal -strata invariably rise upon their approach to these hills ; and even the subjacent bed, the limestone, upon which they rest, is sometimes thrown up to the surface, as at G racedieu, where it is seen resting on the flanks of the porphyritic rocks of Whitwick. The circum- stance on which the hopes of success at Billesdon were built, when the coal-strata which it was thought were traceable at the surface, had eluded detection, was, that the regular coal-formation might have been brought near to the surface in this situation, by the up- heaving of the Forest rocks and the circumjacent beds ; but it should 97 The vegetable remains thus accumulated are quite dissimilar to those which we shall hereafter find con- stituting the coal-formation. An entirely new and distinct vegetation seems, at the period under considera- tion, to have clothed this portion of our planet, and plants analogous to those now flourishing at the Cape of Good Hope, and in New Holland, appear to have been common. It would far exceed our limits to describe each of the various formations of which this group is composed. The Lias, the lowest member of the series, is, however, peculiarly entitled to consideration, on account of its organic riches. It is highly prolific in animal remains, have been remembered, that the elevation of these rocks took place long anterior to the formation of the superior beds the lias, on which the experiment was commenced, and the red-marl, upon which the lias rests ; for even the red-marl, a much older deposit than the lias, and by which the coal- formation is covered up, rests everywhere undisturbed upon the almost vertical beds of the primitive rofcks, and the lias limestone, the lowest bed in the series of the lias, has obviously undergone no considerable derange- ment. In a Sketch intended merely to exhibit the great physical commotions which have affected the surface of the earth, it would be foreign to my object to enter into the details of a question of practical geology ; and Professor Sedgwick and others have already pronounced their opinion upon this and similar projects : but it may be well to observe, that in any experiment of this nature, where the geographical position is equivocal, a ready and infallible test is always to be found in the distinct character of the vegetable fossils. Ferns, it is true, are common both to the oolitic group and the coal -formation, but the gigantic calamites and palms which characterize the latter, are entirely absent in the former. SeeLindley and Huttons Fossil Flora, preface, vol. 1. E bones of crocodiles, tortoises, fishes, and reptiles ; such as the Mogosaurus, a gigantic species of lizard, with a body twenty- six feet in length, head four feet, and tail ten feet ; the Megalosaurus , a species of monitor or amphibious animal, whose height equalled the largest elephant, and whose length was little short of the largest whale ! the Pterodactylus * or wing-toed reptile, an animal covered with scales like a lizard, and provided with the means of flying like the bat, and of suspending itself from trees like the sloth. Dr. Buck- land has thus described it, " In size and general form and character of its wings, this fossil genus, according to Cuvier, somewhat resembled our modern bats and vampires, but had its beak elongated like the bill of a woodcock, and armed with teeth like the snout of a crocodile ; its vertebrae, ribs, pelvis, legs and feet, re- sembled those of a lizard ; its three anterior fingers terminated in long hpoked claws like that on the fore- finger of the bat, and over its body was a covering, neither composed of feathers as in the bird, nor of hair as in the bat, but of scaly armour like that of the Iguana, in short, a monster resembling nothing that has ever been seen or heard of upon earth, except the dragons of romance and heraldry. By means of its powerful paw and long claws, it was enabled to creep or climb, or suspend itself from trees : thus, like Milton's fiend, * The Rerodactyli have been found in the Stonesfield slate, at Solenhofen in Germany, and at Lyme Regis, at M'hich latter place it is associated with the ichthyosauri and plesiosauri. The limestone of Barrow in Leicestershire is one of the richest repositories of the remains of the ichthyosaurus. 99 qualified for all services and all elements, the creature was a fit companion for the kindred reptiles which swarmed in the seas, or crawled on the shores of a turbu- lent planet."* The fiend O'er bog, or steep, through strait, rough, dense, or rare, With head, hands, wings, or feet, pursues his way, And swims, or sinks, or wades, or creeps, or flies." Paradise Lost, book 2. Insects, it is imagined, were the food of the pterodac- tylus, as, where the remains of these strange creatures are found in greatest abundance, there fossil insects also abound. Like the bat, this winged reptile is supposed also to have shunned the light, and to have made its predatory excursions during the night. Contemporary with the pterodactylus, lived in the marshes and shallow lakes of that period the ichthyo- saurus, or fish-lizard, many species of which have been exhumed from the lias-limestone at Barrow and Lyme Regis. This voracious animal was of a species between the fish and the crocodile, or lizard, furnished with paddles to navigate the water, but unable to live long beneath it * This description is applied to the pterodactylus macronyjc, dis- covered in the lias at Lyme Regis, hy Miss Mary Anniug. It was about the size of a raven. K2 100 like the fish. One species, the Ichthyosaurus platyodon, had jaws eight feet long : it was armed with sharp-pointed teeth, and had enormous eyes to aid its vision in the dark. Cuvier describes the ichthyosaurus as having the snout of a dolphin, the teeth of a crocodile, the head and sternum of a lizard, the extremities of cetacea, * (being, however, four in number,) and the vertebrae of fish. Many entire skeletons have been found, and in such profusion are their remains preserved, that the organization of this strange reptile is as well known to naturalists as that of any animal now existing. Theplesiosazerus. akin to the ichthyosaurus, but approximating more nearly to the lizard, as the term expresses, (plesion, near to, saurus, a lizard) , existed also at this period. The ichthyosaurus, it is imagined might brave the waves of the sea, dashing through them as the porpoise now does, but this animal, at least the long- necked species, fplesiosaurus dolichodeirus \) which the wood-cut represents, would be better suited to have fished in shallow creeks and bays, defended from heavy breakers. f Its enormously long neck, resembling the * Cetacea, the species of mammiferous animals, to which the whale and others belong, from cete, whale. f See Dela Beche'sGeol. Manual, p, 343, where an idea of these reptiles sporting in their native element is attempted to be conveyed. 101 body of a serpent, it is supposed to have carried like the swan, as it floated upon the surface of the water, and used in darting at its prey, the fish. In addition to the reptiles enumerated, there are the remains of animals analogous to the frog and the toad, and fish in a great variety. * " With flocks of pterodactyl!, observes Dr. Buckland, flying in the air, and shoals of no less mon- strous ichthyosauri and plesiosauri, swarming in the ocean, and gigantic crocodiles and tortoises crawling on the shores of the primeval lakes and rivers, air, sea, and land must have been strangely tenanted, in these early periods of an infant world !" Many of the animals buried in the lias, appear to have lain but a short time exposed to the effects of de- composition, as skeletons of ichthyosauri have been found with vestiges of the skin and flesh upon their bones, and the contents of their stomachs between their ribs, fossilized of course, but proving that their envelope- ment in the sedimentary matter must have speedily followed death. The ink-bags in the fossil sepia, which retain their forms precisely as they exist in animals possessing organs of a similar description at the present day, are also a remarkable instance of the preservation of delicate animal substances by their conversion into hard unyielding stone. The recent discovery of the faeces of the ichthyosaurus, to which the term coprolites has been given, is one of the most singular results of geo- * It is singular that the scales of fishes should be beautifully preserved where no trace of bones remain, although the bones are formed of far less destructible materials than the scales, which, in fact, consist almost entirely of animal matter. K3 104 formation emerges : in some places it is covered by the red-marl, in others by the magnesian limestone, and higher beds of this group, and in the west of England, even by outlying portions of the superior formations, the lias and oolite, while in many situations, and indeed generally, it is found stripped of all the superincumbent beds. The vast quantity of vegetable remains imbedded in the strata accompanying the coal, of an accumulation of which, in fact, that substance itself consists, opens to us an unbounded field for conjecture and astonishment. We have now done with the relics of crocodiles, ichthyosauri, plesiosauri, and pterodactyli, and must bid adieu to all traces of the inhabitants of terra firma. We found, as we went back into their history, that they be- came less and less like the existing races. Now they have entirely disappeared. In a mass of a thousand feet of co&\-measures (the strata associated with coal) described by Mr. Mammatt, * only one bed of a few inches in thickness, containing marine remains, is mentioned, yet every yard abounds in vegetable impressions, which botanists assure us all belong to tropical climates. Many of the genera of these plants remain undetermined, but it is universally agreed that a high temperature was indispensable to their production. The regularity of thickness of the strata of coal, and their uniformity throughout an extensive area, is one of their most re- markable features. They are commonly described as existing in basins, but the term is not universally appli- cable, for although many of our coal-fields occupy basin- * Geological Facts of the Leicestershire Coal Field, 1834. 105 shaped depressions in the older rocks there are others which are not so circumscribed. We have seen that accumulations of vegetable matter forming coal, took place during the deposition of the oolitic rocks : in the Paris basin also, and in other forma- tions, supposed to be of still more modern date, as the Bovey lignite in Devonshire, and the yet more remark- able brown coal-formation of the Rhine, proved to have been formed during the action of the extinct volcanos which so long convulsed the neighbouring district of Neuwied and Eifel, and at a period when the climate approached that of the present temperate regions of the globe, for here we find imbedded the oak, the fir, the beech, and other forest trees of Europe. * And coal-formations are thought to be going on at the present time in the large rivers, lakes, and morasses of America. The phenomena of the coal-formation appear at first sight to admit of an easy explanation. The lux- uriant vegetation of the primeval world might furnish the requisite quantity of vegetable matter. The earth is known to produce bitumeirf in great abundance, both * See Dr. Hibbert on the extinct volcanos of Neuwied. f Bitumen is found in many parts of the world in a fluid state, as on the lake Asphaltites in Judea, and in other volcanic regions. In the island of Trinidad there is a lake of pitch or asphaltum. Montgomery Martin in his History of the Colonies, thus describes it : The lake is bounded on the N. W. by the sea, on the S. by a rocky eminence, and on the E. by the usual argillaceous soil of the country; it is nearly circular, and better than half a league in length, and the same in breadth, occupying a point of land which shelves into the sea, from which it is separated by a marg : n of wood; the variety and extraordinary mobility of this pheno- 106 in a fluid and solid state, and carbon, the other ingredient of coal, and an essential element of vegetation, might have existed in the atmosphere, or in the waters, in much greater abundance than at present. It has been suggested, indeed, that it was the gradual abstraction of carbon from the atmosphere, by the successive formation of coal and limestone, at this period, and subsequently going on, which fitted it by degrees for the respiration, first of reptiles, then of mammifera and the higher races of animals. Either the atmosphere, or the waters, or both combined, must indeed have furnished an im- mense supply, for every cubic yard of limestone has imprisoned in its mass sixteen thousand feet of car- bonic acid gas, and it constitutes a large portion of the substance of coal. But although the air, the earth and the waters, might furnish the materials, the mode by which such vast accumulations of vegetable matter were effected, is inexplicable. Thus, ill Staffordshire we have a bed of coal ten yards in thickness, and at Saint Etiehne, in the south of France, it is sometimes sixty feet thick, and in these instances, the thick bed is only the principal one of a long series of strata of the menon is very remarkable: groups of beautiful shrubs and flowers, tufts of wild pine-apples and aloes, swarms of magnificent butter- flies, and brilliant humming birds, enliven a scene, which, without them, would be an earthly representation of Tartarus. Where a small islet has been seen in the evening, a gulph is found on the following morning, and on another part of the lake, a pitch islet has sprung up, to be in its turn adorned with luxuriant vegetation, and then again engulphed. Pieces, of, what was once wood, are found completely changed into bitumen ; and the trunk of a large tree, on being sawn, was entirely impregnated with petroleum." 107 same composition, alternating with dissimilar matter, such as ironstone and shale, to the depth of many hundred yards. In the Alps there are vertical beds of coal, and here, as in other instances, where a violent derangement of the strata has taken place, the coal has parted with its bitumen, and is found as anthracite, * or pure carbon, being with the associated beds highly indurated ; the shale elsewhere soft, here assumes the hardness of roofing slate, for which, in Savoy, where it is used indeed as a covering for houses, it might be mis- taken, but for the vegetable impressions still observable in its substance. The alternation of layers of coal with shale, fire-clay, and other distinct accumulations of earthy matter, which occur sometimes even in the coal itself, would seem to indicate that these substances were originally held in solution in a fluid from which they were quietly precipitated, and arranged according to their specific gravity ; but the occurrence of plants, such as the calamites and palms, so common in coal measures, in the vertical position in which they grew, proves that the matter in which they are enveloped was a sediment mechanically deposited from the water, which tranquilly and gradually covered them : a quiet process it must have been, for in many cases, although the outer cuticle or bark, is carbonized, and the interior converted into the substance in which it is imbedded, the stems of these plants are not in the least compressed. The fossil vegetation of the coal-formation not only indicates a tropical temperature, but it has been inferred from the gigantic size of many of the imbedded plants, * Anthracite, from anthrax, coaL '108 in comparison with those of similar species now existing under the most favorable circumstances within the tropics, that they must have flourished in a climate much hotter than that of the equatorial regions , of the earth at the present day. Thus, Brongniart has de- scribed fossil tree-ferns* forty to fifty feet high, and Lycopodiaceae, a species of plant between the pine and the fern, known as club-mosses in the north of England, where the mountainous heaths produce them, and they rarely reach a height of more than two or three feet, are found in the fossil state sixty or seventy feet long. If the size is remarkable, much more so is the amazing geographical range of these fossil flora, for wherever the carboniferous strata have been examined, the vegetable impressions are of the same kind. Thus, Captain Parry brought from Melville Island, within fifteen degrees of the North Pole, fossil specimens of a tropical vegetation, corresponding precisely with those which characterize our coal-measures ; and calamites, differing in no respect from that common fossil plant of this country, have been brought from Port Jackson in New Holland ! Indeed, there is no fact disclosed by geology so extraordinary as the uniformity of character of rock-for- mations in regions remote from each other. Humboldt * The island of Dominica, situate within fifteen degrees of the equator, is celebrated for its forests of tree-ferns. " The size of the ferns," says Montgomery Mai-tin, " is very remarkable ; some of them rise to the height of twenty-five feet, (only half the size of the fossil species,) with the branches as finely pennated, and their colour as vivid and fresh, as the , dwarfish and lowly but lovely English fern." 109 remarks with great beauty and propriety, " that while on entering a new hemisphere we change all other familiar and accustomed objects; while in the plains around we survey entirely new forms of vegetable and animal beings, and in the heavens over our heads we gaze upon new constellations, in the rocks beneath our feet we recognize our old acquaintances." We know that at the discovery of America by the Spaniards, none of the species of animals and plants found there pre- cisely corresponded with those of the old world ; and of the effect of climate in circumscribing their abode we have everywhere evidence. But in the primeval world none of these lines of demarcation appear to have ex- isted : tropical plants grew alike at the pole and the -equator, in both hemispheres ; and at a later period, as we have seen, the equatorial elephant ranged from the torrid to the arctic zone. There are those who affect to despise geology,* and designate it as a crude uninter- esting collection of far-fetched facts. Is there no interest in facts so novel, results so unlooked-for as these ? The subject of the coal-formation has ever been a fertile theme for those who delight to reflect upon the evi- dences of design manifested in the great works of Creation: the accumulation of such a vast mass of vegetable matter, produced, apparently by fortuitous revolutions, at remote periods in the history of the earth, for those who should after wards inhabit its surface, cannot indeed fail to strike the attention of the least observing : the * Mr. Croly, in his work on Divine Providence, says, that " Geology is a meagre collection of trivial facts, gathered by loose enquiry, and arranged by imperfect knowledge." L 110 very faults, as they are termed by miners, the dislo- cations, elevations, and depressions of the strata, have been held to be advantageous, inasmuch, as they some- times bring within reach beds of this mineral, which would otherwise be inaccessible, and confine within limits the subterraneous waters, which would otherwise accumulate in such quantities as to defy all the efforts of the miner to draw them off. Immediately beneath the coal-measures, which in some cases are themselves three thousand feet in thick- ness, and connected therewith in the usual classification of the carboniferous group, we find an extensive series of beds of limestone, sandstone, and conglomerate. The limestone, which, from the great elevation it attains in Derbyshire and Yorkshire, has obtained the appellation of mountain-limestone, may be said to form the base or bottom of our regular coal-formations, from the coal-measures being so frequently found resting upon it, although in some parts of Europe, and in America, coal is said to occur much lower in the series. * The passage from the plastic clay to the chalk is not more abrupt and remarkable than is the transition from the coal-measures to the subjacent beds; the former containing only terrestrial remains, the latter exclusively marine, which differ also entirely from the organic contents of all the subsequent formations. Zoophytes, or the coral tribe, and shelly animals of the crustaceous species, appear to have been the principal * As the anthracite, worked for profitable purposes, in Brit- tany, in Calvados, and in the Vosges, according to M. Elie de Beaumont, and in Ireland, according to Mr. Weaver. Ill inhabitants of the ocean, in whose bed these rocks were formed. Myriads of polyparia, indeed, encrenites and madrepores, such as those figured in the margin, must at this period have luxuri- ated in a tranquil sea, and built up considerable masses of solid rock, form- ing perhaps islands, and coral-reefs, as in the Pacific ocean at the present day. In England the mountain limestone is of great mineralogical importance, it being the main depository of our lead-ore and other metals. That singular substance, elastic bitumen, is frequently found in the accompany ing beds, the mill- stone grit, and lime- stone shale of Derbyshire, and even the fluid varieties, naphtha and petroleum, have been discovered there. Under the carboniferous group, although in this country, frequently rising higher than any of the beds hitherto described, lie the transition * rocks, now more generally known to geologists by the euphonious appel- lation of the yrauwacke group. In these, the first link in the chain of fossiliferous rocks, the organic remains * The secondary formations which commence with the chalk, terminate at the grauwacke, where the transition begin : they were called transition rocks, because their organic remains seemed to mark a gradual developement of animated beings, from the pri- meval void, but this idea is abandoned, for there does not appear that dearth of organic structure which was at first supposed. L 2 112 are generally very obscure. The Dudley limestone is perhaps the most prolific. A multitude of little animals or insects, (the trilobite) , of a species unlike any existing, or imbedded in other rocks, pervade this mass. In Wales, between the lami- nae of the slate, they are also abundant, and they are, in fact, common to Eu- rope and America. From the myriads of these found together entombed, and the contracted attitude in which they are frequently observed, it is inferred that their destruction was the effect of sudden catastrophes, which overtook a whole herd, and as suddenly enveloped them in the matter, which subsequently became hard rock. Five hundred and forty-six species of shells, zoophytes, crustaceous animals^ and plants, have been identified with this ancient group of rocks, and among them there are several genera, which still occupy a place in the animated creation, having survived all the changes and convulsions, in which so many tribes of beings have perished. As we approach the primitive rocks all traces of organized beings vanish. From man to the screw-like encrinite from the caverned bones to the transition rocks we have seen a continuous chain in the types of animated beings, whose petrified relics tell the tale of their existence. Here, however, it is broken off, the light by which we have thus read the history of created beings is withdrawn. We appear to have arrived at the period when the Omniscient fiat first imparted life to inanimate matter: and have now to contemplate " the earth without form and void." It has been suggested indeed, that the absence of 113 fossil remains in the early sedimentary strata, is no proof of the absence of life at the period when they were deposited : but that the first organized beings might have been of the class of those gelatinous, flesh- like substances, to which the name of Medusae has been given (from the organs of motion spreading out like the snaky hair of the fabulous Medusa) . The ocean it is said might have swarmed with these, and no traces have been left of their existence. 114 NON-FOSSILIFEROUS ROCKS. Hitherto, water has been the principal agent in the production of the great physical changes, which we have reviewed. All the sedimentary strata, whether they be clay or hard rock, chalk or marble, sand or sandstone, are vestiges of the dominion of the universal ocean, or of subordinate masses of its world-encircling waters. Everywhere its presence at successive periods may be traced, and so extensive appear to have been its opera- tions, that we might almost have arrived at the conclu- sion of Thales, that all things had their origin in water- But another powerful agent, which we have seen operat- ing in volcanos, must now be introduced, to account for the phenomena of primitive* and other non-fossilife- rous rocks. Although we cannot consult the archives of nature * These rocks being destitute of organic remains and generally beneath all the other formations, are supposed to have existed ante- cedent to the creation of animated beings, to be in fact, coeval with the origin of the earth itself, and of the same nature as the interior of the globe hence the term primitive. Some geologists have conjectured that the primitive rocks are themselves merely the fused wreck of pre-existing masses, but this endless system of mutation> which they would thus establish, lacks both proof and analogy. 115 in the organic contents of these masses, they present to us internal evidence of their origin, scarcely less equivo- cal. Instead however of tracing the progress of tlie development of animals and vegetables r-of beholding in imagination regions now sterile clad with tropical splendour, groves of umbrageous palms in situations where the degenerate soil now produces only the bram- ble, of watching with satisfaction the gradual extinc- tion of the hideous monsters, which dwelt in countless herds in pestiferous marshes now transformed into scenes of fertility, it is our business to examine the changes which inorganic matter has undergone, an in- vestigation not less interesting in its results, but requir- ing a knowledge of which we have hitherto had no need, of chemistry and mineralogy, without a slight acquain- tance with which, the subject is unintelligible. In the primitive rocks no traces of organized re- mains have been observed : they present, in fact, a field of enquiry which lies beyond the range in which we have hitherto been confined ; we here appear to have reached the fountain head of the long and varying stream of organized being which we have imperfectly and hastily traced, the source from whence animated nature first sprang the period of creation : a result of science, which those who have indulged in the dream of the eternal duration of things, never expected to witness. This division of the subject of my " Sketch" well deserves a separate volume, it must, however, be briefly dismissed. In the primitive rocks, which consist partly of stratified, and mainly of unstratified masses, known by the names of granite, gneiss, mica slate, primitive limestone, and other local appellations, the greater part 116 of our metallic treasures lie concealed. These are usually found in veins or irregular lines of extraneous matter, which traverse in all directions and to an unknown depth, both stratified and unstratified rocks. The ancient notion was, that veins were branches and twigs of an immense trunk, which exists in the interior of the globe, raised in the form of vapours and exhalations through the rents and crevices, as the sap is raised and circulated in trees, and that the substance of which they are formed was elaborated from the materials of the rocks. In recent times several theories have been adopted to explain these phenomena, but their origin is still in- volved in obscurity: 1st, that they were open fissures caused by the contraction or subsidence of the rocks, and afterwards filled by aqueous solutions, poured in from above, or by sublimation ; 2nd, that these rents were the effect of internal violence, and were filled by fused materials ejected from beneath ; 3rd, the theory of Dr. Boase, which assigns their origin to the same period and circumstances as the masses which enclose them.* In some instances however, there seems positive indica- tions of a difference of age, as where metalliferous veins are crossed by others, they are displaced, and a disturb- ance in the line of direction of the intersecting veins takes place,t significantly termed by the miners a heave, Mr. Robert Fox was the first to point out the * Professor Sedgwick suggests, that there are three different sets of veins, which may be referred to each of these hvpotheses, f See Taylor's Communication to the British Association, on Mineral Veins. 117 probable connexion between the direction of veins and magnetic currents, but experiments are yet wanting to prove the analogy. That this mysterious agency will hereafter solve many phenomena at present inexplicable, the extraordinary results already disclosed by the science of electro-magnetism, give us reason to expect. The parallelism of metalliferous veins, and their tendency in this country, throughout the mining countries of Europe, and in the great mines of Mexico, to an east and west direction, is a very remarkable fact.* The primitive rocks are all crystalline, that is, formed of an aggregate of crystalline substances, united in certain proportions. Now in order to effect crystal- lization, the particles of matter must be allowed to range themselves freely, or, in other words, the mass must be in a state of fluidity ; and this may be produced in two ways, by fusion or a separation of the particles by the infusion of heat, and by solution in an acid or other fluid. Now, although lime and many other substances and salts may be readily held in solution, silex (the material of which these rocks is chiefly composed) , can only be dissolved at a very high temperature. Hence it has been very rationally inferred, that the primitive rocks were rendered fluid previous to thfeir crystalliza- tion, by means of heat, and many facts seem to confirm this hypothesis. Thus they are found penetrating into the substance of other rocks in fissures and crevices, like the veins referred also to igneous origin, and in * This circumstance is particularly observable in Cornwall, wher,e the productive veins have generally the east and west bearing. some cases to have flowed over and covered them : and, moreover, they are seen to pass by insensible gradations into those compounds termed basalts, and other rocks which are known to have had a volcanic origin. Hence the inference is now general, that all the unstratified rocks have undergone fusion by heat. The uniformity of the predominating rock granite, is very remarkable, and indicates that it was everywhere formed under the same circumstances. Thus there are specimens from Dartmoor and Mont Blanc, in which no difference is distinguishable. In fact, the resemblance will always be found, although the proportions of the ingredients may differ, if we compare specimens from the Alps or the Alleghanies, India or Australia. Akin to the granite, and other primitive formations, are the basaltic or trappean rocks, which belong to all ages, from the primeval epoch to the recent volcano. They are found traversing strata of every description, in some instances quietly interstratified with sedimen- tary beds, in others, displacing and deranging the strata, and leaving traces of their having been forcibly intruded. Here, they may be observed capping the summit, or flank- ing the sides of a hill in irregular masses, there, rising from the bosorfi of the deep in stately architecture, or a heap of amorphous * basalt may be seen resting upon clusters of columns, as in the Cyclopean islet, in the bay of Trezza, represented in the frontispiece. Here their connection with the lava-streams of Etna is obvious, while in other situations they merge by insensible gra- dations into primitive rocks. Where, as in the former * Destitute of regular form a without, morphe form. 119 instance, they flow from volcanic craters, their igneous origin is indisputable : it is not less certain in the latter, where they may be far removed from volcanic action. For wherever the basalt appears, whether in the colossal columns of the Hebrides and the Giant's Causeway, which rise in majestic grandeur out of the waves of the Atlantic, or in subterraneous dykes running in straight lines across a whole country, and extending to unfath- omable depths beneath the surface of the earth, as in the remarkable trap-dyke of Yorkshire and Durham, which may be traced in a linear direction for a distance of sixty miles, * indelible marks of the action of fire, is always imprinted upon the mineral masses around them. Coal is converted into coke, f or charcoal, or anthracite, chalk discoloured and metamorphosed into indurated limestone, sandy beds changed into siliceous rocks, and the strata upheaved, dislocated, or contorted. All the ancient crystalline rocks exhibit a tendency to the prismatic structure, even where regular polygonal forms have not been assumed, the particles are so ar- ranged in the rocks, as to incline them to cleave in a * From High Teesdale to the eastern coast, according to Pro- fessor Sedgwick. f As in the case described by Mr. Hill at the Walker col- liery, Newcastle, and in other situations. At the Whitwick colliery in Leicestershire, a bed of dark amorphous basalt, twenty yards thick, is found protruded horizontally into the coal-formation, through the red-marl which overlies it. The coal is charred when the basaltic mass approaches it, and the upper seam heaved out of its true position. The thickness of the basa.lt diminishes rapidly as it recedes from the porphyritic rocks of Charnwood Forest, with which it is evidently connected. 120 certain direction in preference to others, and it is re- markable that in this country the most constant clea- vages in these tabular masses rise " perpendicularly, with a direction from N. N. W. to S. S. E." * The inter^ section of these lines of cleavage often gives the character of the columnar structure to a rock, f Even sandstones sometimes separate into rhomboidal forms ; and this tendency of rocks, both chemical and mechanical, to arrange themselves in determinate figures, has been generally observed in situations which lead to the sup- position, that they have been exposed to intense heat. In the practice of baking a loose sandstone of the coal- formation, in Yorkshire, for road-materials, a columnar structure is frequently observed to have been produced. These columns vary in the number of their sides, are generally curved, and about half an inch in diameter. In this case the heat is insufficient to fuse the silicious particles of sand ; it has merely driven them into closer contact, and the effect of this induration, is the columnar structure. } Sir James Hall discovered the * De laBeche's Researches, p. 187. f On the summit of Beacon hill, one of the highest eminences in the Charnwood Forest range, Leicestershire, this is well illus- trated ; in fact, many portions of the rock have there assumed the prismatic structure. It is worthy of observation, too, that the lines of cleavage of these schistose rocks correspond, in the main, with those general linear directions observed in Cornwall and elsewhere, namely, N. W. by W., and S. E, by S., dipping about 72 degrees to the N. E. J Dr. Maculloch, instances the sandy hearthstone of a blast furnace at the Old Park Ironworks, near Shiffnal, in which long- continued heat had produced the prismatic structure, without changing the chemical nature of its constituent particles. same tendency in the minerals which he succeeded in crystallizing under pressure. But Mr. Gregory Watt's beautiful experiments upon basalt, of the amorphous kind, from Rowley rag, near Birming- ham, actually exhibit the mode in which this archi- tecture of nature, the columnar structure, is effected. He observed, during the progress of cooling a large mass which he had succeeded in fusing, the formation of spheroids, or globular masses, sometimes extending to a diameter of two inches, with distinct fibres radiating from a centre, and forming concentric coats, the middle speedily becoming compact. The process being continued, he further observed, that where these bodies came into contact in the cooling fluid, they were mutually compressed, and became separated by a well-defined plane, which, as numbers accumulated, formed hexagonal, or six-sided prisms, an effect which seems in- evitable, where accumulations of particles, arranging them- selves round distinct and equi- distant centres, press upon each other : as the figure will illus- trate. * His inference from this was, that where an indefinite number of these im- penetrable spheroids come into contact on the same plane, (or horizontally,) their mutual action would naturally form them into hexagons, which, in the ab- sence of a counteracting effect from above, would rise * Of course the diagram is intended to represent an horizontal section of the spheroids and hexagonal concretions. M 122 into columns or prisms, in the way in which they are found in nature. Where, however, any combination of circumstances prevented this arrangement, the globular concretions would remain, an effect which Dr. Daubeny subsequently found a beautiful illustration of, in the volcanic region of Eifel, which is thus described : "A curious illustration of the formation of basalt occurs in a natural grotto, formed at the junction of two basaltic streams. The walls of this grotto are composed of basalt, slightly cellular, and forming a number of con- centric lamellar concretions, and somewhat compressed, so that the interstices between the balls are filled up. It obtains its name, cheese-cellar, from the similarity it presents to Dutch cheeses piled upon each other. It beautifully illustrates the origin of the jointed columnar structure, which this rock so often assumes, since a little more compression would have reduced these globular concretions into a prismatic form, each ball constituting a separate joint in the basaltic mass. The most probable way of accounting for the existence of this natural grotto, is, to suppose the lava which forms its walls to have cooled near the surface, before the mass had ceased to flow into its interior : hence, a hollow would be left in which the basalt had room freely to assume the form most natural to it, and the con- cretions, being but little compressed on account of the cavity within, retain their original globular figure. In further proof of this, it may be remarked, that the lava above the grotto consists of irregular prisms, and not of balls, as is the case with that which constitutes its walls." Some of the ancient basaltic columns of the Hebrides too, when stripped of their outer coats, appear to be 123 composed of an accumulation of cannon-balls and bomb-shells, piled vertically upon each other. Thus does science become familiar with the arcana of nature, and in this manner sometimes anticipates her secret operations ! 124 CONCLUSIONS To the hasty and imperfect outline of the leading facts and phenomena which geological research has brought to light, it remains now for us to glance at the hypotheses which they have suggested ; to fill up the sketch, by introducing the causes which have produced the great physical changes, the effects of which we have faintly shadowed forth, and to throw over the whole a few reflections, which the contemplation of a subject so vast inspires. To the immediate agency by which many of the phenomena delineated have been produced, refer- ence has been made in the body of the sketch : the causes which produced the extraordinary oscillations of land and sea, the dislocation and elevation of the strata, and the high temperature of the primeval earth sub- jects which come within the range of physical astronomy, have engaged much of the attention of philosophers in recent times, and interesting and unlooked-for conclu- sions have resulted from the enquiry. All the facts we have considered conspire to prove that the earth, at early periods of its history, enjoyed a much higher temperature than at present ; that the climate of the frigid zone, for instance, at the period of the forma- tion of coal, was even hotter than that of the tropics in these days : and there are many circumstances which 125 seem to indicate a gradual decrease of temperature, as a gradual approximation to the present state of things is observed. In the solution of this subject of enquiry all geological phenomena appear to be involved. A recent discovery in astronomy suggests a possi- ble explanation of the cause of the decreased tempera- ture.* It is evident that without the rays of the sun the surface of the earth would be densely cold : this is proved, if proof were wanting, by the cold which ensues from its temporary absence during the night, and the intense frost of the arctic regions during their long solar night. It is equally obvious that the mean temperature depends upon the mean quantity of the sun's rays re- ceived in a given period. Now it is ascertained that the elliptical orbit of the earth is undergoing a slow, but gradual approach to a circle, or in scientific language, the minor axis of the ellipse is gradually on the increase, while the major axis remains the same. The consequence, therefore, is clear, that the annual amount of solar radia- tion from this cause is gradually decreasing, as it must be inversely proportional to the minor axis of the ellipse, consequently the mean annual temperature is lowering. Hence we have a cause operating, as Sir John Herschel observes, in the right direction, but whether adequate or not, remains to be determined. Another astronomical cause has been suggested, and, in fact, was generally adopted by the early geologists, namely, a change in the position of the earth upon its axis, produced not gradually, as in the motion known to *See Herschel's Treatise on Astronomy ; or Geological Tran- sactions, 2nd series. M 3 126 astronomers in the precession of the equinoxes, but sud- denly and violently by some external agency, such as that of the contact of a comet, which according to Whiston and others, was the secondary agency employed to pro- duce the creation of the world and the deluge. But this change, whether brought about suddenly or by degrees, would have the effect only of bringing certain regions under the solar influence, which before had enjoyed but a scanty portion of the sun's rays ; it might remove the polar regions to the equinoctial, and transfer the equator to the pole, but it is insufficient to account for that generally-diffused high temperature, which geological phenomena attest. Moreover, astronomers assure us that no permanent change in the position of the earth upon its axis can have been effected : there being in all rotating bodies not perfectly spherical an inclination to revolve on a certain axis in preference to all others, had any derangement occasioned by external violence taken place, equilibrium would have been speedily restored, and rotation upon its natural axis resumed. It is obvious, however, that the least oscillation or derangement in the motion of a ponderous body whirl- ing with inconceivable velocity upon its axis, would produce an extraordinary effect upon its surface, more particulary upon the ocean, so sensitive that it invariably rises when in the presence of a planetary body, which never approaches within so short a distance as two hundred thousand miles. Some such violent catas- trophe seems almost indispensable to effect the sudden revolutions of which we have geological evidence, such as those in which whole races of living beings were an- nihilated, solid strata turned upside down, or large 127 animals transfixed in ice. These effects, on the other hand, the theory of secular refrigeration, as it is termed, by the diminution of the excentricity of the earth's orbit, is utterly inadequate to explain. Mr. Lyell argues tha an alteration in the relative distribution of land and sea, and the elevation' and depression of mountain-chains, may have occasioned the change of climate : and en- deavours to shew that changes of climate and elevation of mountain ranges were contemporaneous over the European area : * that at the period of the luxuriant vegetation of the northern latitudes, the great continent which now encircles the pole lay beneath an ocean studded with islets and coral reefs, like the present Pacific, while lofty mountains reared their heads above the clouds at the equator. As poets are licensed to stop worlds upon their axes in order to usher in a great event with becoming solemnity, f so theorists may take the liberty of mould- ing the earth at their pleasure, of smoothing down the slight asperities of mountains and valleys, to clear the ground for a favorite hypothesis ; but geologists, in general, are not disposed to adopt these sweeping generalizations, where there are no analogies to guide, and facts are too vague to lead to determinate conclu- sions. The idea now generally entertained is that origin- ally struck out by Leibnitz, that the high and equable temperature of the earth at remote periods was owing * Principles of Geology, vol. 1 , Chap. 7 and 8. f The idea of Klopstoek, in his Messiah, when the incarnation is resolved upon. 128 to the radiation of heat from the globe itself, which has been gradually decreasing from the earliest times. That great heat does exist in the interior of earth, no matter whether inherent or not, volcanos and thermal springs attest. And although many writers, among them Mr. Mammatt, in his recent practical treatise upon the Ashby Coal-field, have treated the idea with ridicule, there does appear to be fair evidence of an increasing temperature from the surface of the earth downwards. Mr. Mammatt made many observations upon the tem- perature of the mines of Ashby- Woulds, the result of which, he states to be, that there is a regular tempera- ture at all considerable depths beneath the surface, of about 46 of Fahrenheit, and whenever he observed an increased temperature, which he could not fail to do at great depths, he attributes it to the heat given out by the combustion of pyrites, or to some local ac- cidental cause. But the conclusion at which he arrives rather tends to confirm the theory which he attempts to invalidate. If there were no supply of heat in the interior, whence originates this uniformity of temperature ? Why does the thermometer indicate 46 Fahrenheit at all depths ? The solar influence extends but a few yards beneath the surface, and mineral masses are bad con- ductors of heat. Whence then is the heat derived ? the atmosphere warmed by the sun's rays can have no effect, for it has not access, yet water rising from great depths is frequently hot, and never found in a state approach ing even to congelation, as one might expect to find it, where the heat of the sun never penetrates. M. Cordier's ex- periments, upon which he established an increase of temperature from the surface downwards, in the ratio 129 of one degree for about sixty-five feet of depth, have been tested in the mines of Cornwall, three times the depth of those at Ashby, and the result singularly confirmed, where every precaution was taken to secure accuracy. In the deep mine at Monkwearmouth, to which I before alluded, the thermometer, excluded from the external air, stood nearly twenty degrees higher in the mine, than at the surface. * A general inference, how- * The experiments at Monkwearmouth being recent, and con- ducted by men of science, the following statement from the Durham Advertiser may not be wholly misplaced. "A barometer at the top of the shaft stood at 30.518, its attached thermometer being 53 of Fahrenheit. On being carried down to the new workings, (1584 feet below the top), it stood at 32.280, and in all probability higher than ever before seen by human eye! the attached thermometer being 58. Four workings or drifts had been commenced in the coal ; the longest of them being that " to the dip," twenty-two yards in length and nearly two in breadth,-^-to the end of which the current of fresh air for ventilating the mine was diverted, (and from which, the workmen employed in its excavation, had just departed,) was selected for the following thermornetric observations. Temperature of the current air near the entrance of the drift* 62" Fahr. near the end 63 ; close to the face or extremity of the drift, and beyond the current of air, 68. A piece of coal was hewn from the face, and two thermometers placed in the spot just before occupied by the coal rose to 71. A small pool of water was standing at the end of the drift. Temperature of this water at eleven o'clock, 70" ; three hours later, 69^". A register thermo- meter was buried eighteen inches deep below the floor, and about ten yards from the entrance of the drift ; forty minutes afterwards its maximum temperature was 67. Another register ther- mometer was similarly buried near the end of the drift, and after a similar period, indicated a maximum temperature of 70. It was then placed in a deeper hole, and covered with small coal; some water oozed out of the side of this hole 130 ever, adopted from partial observations, is always liable to error ; until, therefore, experiments are multiplied, the theory of central heat deduced from these alone should be advanced with diffidence. In all science it is much easier vaguely to speculate, than patiently to observe. The figure of the earth, which, as is well known, is not a perfect globe, whose surface is everywhere equi- distant from the centre, but a spheroid, whose equatorial diameter exceeds in length the polar axis by twenty-six miles, or 1 -305th of the diameter, has been supposed to indicate that the whole mass was originally in a state of fluidity, or fusion ; as it is said to be precisely that which a globular mass of matter thus circumstanced, (the particles moving freely among each other and the whole rotating upon an axis,) would naturally assume. To the gradual and partial internal cooling of this heated mass after the surface had become consolidated, the numerous fractures in the strata, undulations, and mountain-ranges, have been referred. Every portion of the earth presents us with instances of elevated, depressed, or contorted beds : to the depth of six or eight inches above the thermometer, which, upon being examined after a sufficient interval of time, indicated a temperature of 7l". A stream of gas bubbles, (igniting with the flame of a candle), issued through the water collected in this hole : the bulbs of two very sensitive thermometers, were im- mersed under water in this stream of gas, and indicated a temperature constantly varying between 7 1.5 and 72.6. A thermometer was lowered to the bottom of a hole drilled to the depth of two-and-a- half feet, into the floor of another of the workings, and the atmos- pheric air excluded from by a tight stopping of clay : this thermo- meter being raised after the lapse of forty-eight hours, stood at 7 1.2 degrees. 131 there is not in England an area of eight or ten square miles, in which the strata have not been fractured and deranged more or less ; in mountainous countries this is more particularly the case, for in these we sometimes find strata sedimentary deposits of sand or pebbles which must have been originally horizontal, actually forced into a vertical position ; and in great mountain- chains indeed, the strata generally lean on each side of the central ridge, like the roof of a house, being more or less inclined in proportion to the height of the upraised basement. Now, forces which could effect the elevation of the Alps, the Andes, or the Himalaya, we can scarcely contemplate without alarm, so vast do they appear to our narrow conceptions, but viewed with reference to the mass of the globe, they dwindle into insignificance, and, supposing it to have undergone any considerable change of temperature, it is obvious that less effects could scarcely have been produced. Our highest mountains are less than four miles in perpendicular height, and the deepest depressions of the ocean probably do not far exceed the elevations of the land, while our greatest perforations into the interior of the earth the deepest mines, fall short of one-third of a mile mere pin-points or scratches on the surface of an ordinary artificial globe. Supposing the outer solid crust of the globe to rest upon an interior fluid mass,* the oscil- * A lava current is sometimes terra firma above, while it is a molten stream below. Sir William Hamilton lighted small pieces of wood in the fissures of a current of lava from Vesuvius four years after it had been ejected, a circumstance which proves how slowly heat is radiated by mineral masses. 132 lations and dislocations which the strata have undergone are easily explained, but the contraction and expansion of the solid masses themselves, may have been attended with effects which at first sight are not so obvious. Thus, from the experiments of Col. Totten on the action of heat upon minerals, recorded in Silliman's Journal, Mr. Babbage has calculated a table of the expansion of granite, marble, and sandstone, from one to five hundred miles in thickness, produced by variations of tempera- ture, and according to the ratio of expansion he has established, supposing any part of the earth's crust formed of these materials, to be one hundred miles thick, an elevation of temperature of 600 or 800 of Fahrenheit, might raise the surface between two and three thousand feet;* by an additional temperature of 50 upon a mass of the consistency of sandstone ten miles in thickness, a superimposed rock might be lifted up twenty-five feet, and so in the same proportion with greater or less masses ; and while rocks generally expand by being heated, clay on the other hand contracts under the same circum- stances. The theory of M. Fourier, who has obtained some interesting results connected with the decrease of tem- perature as we ascend into the atmosphere, is, that the earth is a globe whose exterior has cooled, but whose interior has still a temperature of enormous intensity, which is not now felt at the surface because of the great mass of non-conducting rock which surrounds it. Mr. Lyell, on the other hand, rejects the idea of the diminu- tion of temperature by radiation, and maintains that * See L yell's Geology, vol. ii., 2nd edition. 133 all the heat of the interior may be referred to chemical and electrical changes in the earth's crust ; and that from the oxydization of the metallic bases of the earths and alkalies volcanic heat is alone derived, and maintained by a continued circle of action, the hydrogen evolved in the decomposition again depriving the heated metals of their acquired oxygen. The theory of M. Elie de Beaumont, which has ex- cited so much discussion, is, that the surface of the earth has been ridged with mountain-ranges and depressions in different directions, by a series of sudden and violent convulsions in the external masses, the effect of the unequal subsidence or contraction produced by the cooling of the fluid interior : that all the elevations of mountain-chains were effected in this manner at certain definite periods, to twelve of which he assigns the moun- tains of Europe, and that the strata raised at each of these successive periods are characterized by a certain parallel- ism in their direction and elevation. It is very question- able, however, whether the age of elevated ranges can be deduced from their parallelism, as we have before observed it has been shewn that there are parallel lines of elevated strata in England of very distinct ages, and others which ought to agree in age, having a different direction.* In considering these complicated geological phe- nomena, we should remember that our earth is not an isolated body, but one of a system of planets, in which it is fair to infer the same general causes are in action, and producing similar effects. Now observations upon the nearest of our neighbours in space, (our satellite the * See Note, p. 88. 134 moon) prove that its surface is indented with mountain ranges and vast depressions like those with which the sur- face of the earth is figured. To astronomers, they<%>- graphytf\hs moon is as familiar as that of the earth; its mountains and valleys have not only names assigned to them, but they have actually been measured, and their heights ascertained with precision ; a regular survey of her disc has been made, and maps drawn with so much accuracy that, it is said, changes from volcanic action may be traced.* It has been observed that if we take Von Buch's account of the earth, in which he describes crateriform amphitheatres of many leagues in diameter, (such as that vast depression or pays cratdre, a volcanic tract around the Caspian sea and lake Aral, contain- ing eighteen thousand square miles, the lowest level of which the waters of the Caspian is three hundred and twenty feet below the level of the Black Sea,) of such amphitheatres encircling central conical craters (as in that vast seat of volcanic action the Thion Cou, south of Altai in Central Asia, extending between seventy and ninety degrees east longitude,) of ranges of these generally disposed in a linear direction (as in the Andes) and such linear trains often radiating from a principal centre of disturbance, we might almost fancy that the description was intended for what we observe in the moon. " Is it then," it is added, "unreasonable to be- lieve, that by more carefully observing these phenomena where we have a whole hemisphere open to our inspec- * Sir John Herschel says, " there are decisive marks of vol- canic stratification, arising from successive deposits of ejected matter in the moon." 135 tion, by comparing the best of the earliest delineations of its telescopic appearances with its actual forms that we may be able to detect any changes in them is it too much to hope that we may thus effectually extend our knowledge of the laws of the volcanic forces, which should appear to be among the general planetary phe- nomena." Who, when he beholds "the mild moon gazing" and " Marks how soft how silently she pours Her chasten'd radiance on the scene below," would imagine that science, with undazzled eye, was ex- ploring in her brilliant disc, a world convulsed, upheaved, and broken, like this ? and that, not content with travel- ing over its surface, it was actually speculating on the geological structure of its interior. Well may the observation of the ancient poet be applied to modern astronomers, " Nil mortalibus arduum est." * Reverting to the theory of central heat, it has been maintained that it may be inferred from the necessity of there being some counteracting agency to resist the enormous pressure of the solid matter constituting the outer mass of the earth. This pressure increases prodi- giously as we approach the centre ; in fact, in such a ratio, that according to the known laws of gravity, no solid substance with which we are acquainted, would be able to resist the pressure at great depths, unless aided by * Horace, lib. i, ode 3. 136 heat, or some other repelling force. * Professor Leslie supposes light to be the only substance of sufficient elastic force to balance a vertical column of three thou- sand five hundred miles, so that the interior of our planet is not, as some have supposed, the abode of dark- ness, but of imprisoned ether, luminous and resplen- dent, eager to break through the adamantine walls which confine it ! an hypothesis which it must be confessed, however it may dazzle, throws no satisfactory light upon the subject. But again, as it is known to astronomers that the density of the planets varies, that is, that it does not coincide with their masses ; (thus Saturn, though infinitely larger than the earth, is far less dense ;) f and the infer- ence being rational, that matter exists upon their surfaces, in something like the same state as upon the earth, from the snow observed upon the polar regions of Mars, which disappears when they are long exposed to the sun, and exhibits the greatest accumulation when they first emerge from the long night of their winter, { combined with the appearances upon the moon's surface, it has been concluded that heat, or some cause counteracting the effect of gravity, operates in a greater or less degree in all the planetary bodies, as well as in the earth. * Even the atmosphere increases very considerably in weight in deep mines, although they in no case exceed 1- 10,000th part of the radius of the earth. See Note, p. 129. f " The density of Saturn hardly exceeds one-eighth of the mean density of the earth, so that it must consist of materials not much heavier than cork." See Sir J. Herschel's Astronomy, p. 278. \ Sir J. Herschel's Astronomy, p, 208, 137 These speculations are not, perhaps, strictly within the province of the geologist : but as reflections which tend to illustrate the harmony of design, evinced every- where in the creation, I have ventured to introduce them. Some modern geologists, letting loose the imagination, have been carried out further into the sea of speculation, and beholding gaseous bodies, such as Encke's comet, whirling in a regular orbit round the sun, with the same force and regularity as the more solid planets ; and looking, moreover, at those vast nebulous bodies in the remote regions of space, which appear to be undergoing condensation, forming, perhaps, new worlds, and sys- tems of worlds by a bold analogy have suggested, that the earth in its original state was an expanded nebu- losity, from the condensation of which it assumed its present form. There is great beauty and sublimity in the idea, that it was thus the globe sprang from chaos at the command of the Creator ; but our position, on the frontier only of knowledge, with faculties which merely enable us just to catch a distant glimpse of what is going on around us, will scarcely justify a step so bold so daring an invasion of the prerogatives of Omnipotence. There are those who, with narrow vision, look with suspicion at geology, nay, who openly denounce the subject as fraught with danger to the interests of religion : and, as it has been observed, * like the Brahmin, who broke to atoms the microscope which first showed him living things among the vegetables of his food, because the discovery was fatal to dearly-cherished prejudices, would crush this rising science, and draw a veil over * See Sedgwick's Discourse on the Studies of Cambridge. 138 the interesting facts which it has disclosed. The venomous ichor, which, according to the mythological fable, flowed in springs from the never-healing wounds inflicted by the thunderbolts upon the Campanian giants, who in the earth had hid themselves to escape the justice of heaven, was not an object of greater horror and abhorrence to the ancient inhabitants of Messapia, than are the organic remains exhumed by geologists, and the deductions which flow from their study, to certain writers and theologians of these enlightened times. This folly, the result of ignorance and miscon- ception, it is idle to expose. Are we to revert to the fable of the North American Indians, that the mammoth, whose bones they find in such quantities beneath the soil, was a reason-gifted monster, which, having laid waste the world, had invoked the lightnings of heaven ; or that the ichthyosaurus, the pterodactylus, the mega- therium, and all those other beautiful specimens of the exuberance of creative skill, which, in countless thou- sands are imbedded in hard rocks, were produced by the lapidifying juices, or some plastic virtue inherent in the earth ? or are we not rather to follow the plain and simple plan of induction, adopted with so much success in the other sciences, deducing causes from their effects, and throwing upon these all the light which analogy furnishes ? There is no medium, no neutral ground of truth; science must be free and unfettered, or suppressed. But, properly considered, geology, in common with all the natural sciences, so far from being inimical, will be found to lend a powerful aid to religion, in exhibiting that beautiful subserviency to final causes displayed in all the operations of nature. That it is not inconsistent 139 with the strictest orthodoxy, we may appeal to Sedgwick andBuckland, and others, as splendid proofs names as eminent in the pages of theology as in the annals of science. And although the beautiful world upon which we dwell, is, as we have seen, but one vast charnel-house of animated beings, containing the remains of number- less races of animals whose prototypes are no longer found in the book of life, and animate and inanimate nature appear to have been involved in an almost end- less system of mutation, the geologist discovers in all these changes such admirable proofs of ulterior design, of adaptation of circumstances to the condition of animal life, of means to an end, and these the more remarkable inasmuch as their connection is sometimes so remote, that he is led irresistibly to the conclusion, that the same Almighty Being which at first created, has at every period of the past, presided over the destinies of his creatures. Science is the language of nature, and " Nature's but the name for an effect whose cause is God." Truly, therefore, may it be said, that Christianity has nothing to dread from the march of science, superstition may shrink at its approach, but revelation may witness its progress without alarm, for, as a beautiful writer has observed, "truths can never war with each other." FINIS. COCKSHAW, PRINTER, * UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY Return to desk from which borrowed. This book is DUE on the last date stamped below. -95m-ll,'50 (2877sl6)476 . i 690896 UNIVERSITY OF CALIFORNIA LIBRARY