Chapter 6

[AM]See Philosophical Trans. Abridg. XI. page 271.

These new strata have been formed by the water which runs on the surface of the earth, often changing situation and dispersing on every side. Part of these waters penetrate internally and flow across the clefts of rocks and stones; and the reason we meet with no water in high lands, no more than on the tops of hills, is, because all elevations are generally composed of stone and rocks, therefore to find water we must dig through the rock till we come to clay, or firm earth, on which these rocks stand, and we shall not meet with any water until the stone is pierced to the bottom: therefore, when the thickness of the rock, which must be pierced, is very considerable, as in lofty mountains, where they are often upwardsof 1000 feet in height, it is impossible to dig to their base, and of course to have any water. There are even large parts of land where there is not any water, as in Arabia Petrea, which is a desert where no rain ever falls, where the scorching sand covers the whole surface of the earth, where there is scarcely any vegetable soil, where the few plants found are sickly, and where springs and wells are so very scarce that only five are reckoned between Cairo and Mount Sinai, and the water of them is salt and bitter.

When the waters on the surface cannot find vent to flow they form marshes and fens. The most famous marshes in Europe are those of Muscovy, at the source of the Tanais; and those of Savolaxia and Enasak, in Finland; there are also some in Holland, Westphalia, and other low countries: in Asia are the marshes of the Euphrates, of Tartary, and of the Palus Meotis; nevertheless there are fewer of them in Asia and Africa than in Europe but America may be said to be but one continued marsh throughout all its plains, which is a greater proof of the modern date of the country, and of the small number of inhabitants than of their want of industry.

There are very great bogs in England, especially near the sea in Lincolnshire, which has lost much ground on one side and gained it on the other. In the ancient ground a great number of trees are found buried below the new ground, which has been deposited there by the water. The same also are met with in Scotland, particularly at the mouth of the river Ness. Near Bruges, in Flanders, in digging to the depth of 40 or 50 feet, a great quantity of trees were found, as close to each other as in a forest: the trunks, branches, and leaves, were so well preserved that the different kinds were easily distinguished. About 500 years since, the land where these trees were found was covered by the sea, and before that time there is no trace or tradition that it ever existed; nevertheless it must have been so, when these trees stood and vegetated; therefore this ground, which formerly was covered with wood, has been overwhelmed by the sea, the waters of which has, by degrees, deposited there between 40 and 50 feet of earth upon the former surface, and then retired. A number of subterraneous trees have been also found at Youle, in Yorkshire, 12 miles below the town, near the river Humber; there are somelarge enough for building; and it is said, perhaps improperly, that this wood is as durable as oak. The people cut them into long thin slips, and sell them in the neighbouring towns, where they are used for lighting of pipes. All these trees appear broken, and the trunks are separated from the roots as if they had suffered the violence of a hurricane, or an inundation. This wood greatly resembles willow, it has the same smell when burnt, and makes charcoal exactly like it.[AN]In the Isle of Man there is a marsh six miles long by three broad, it is called Curragh; subterraneous trees, like willows, are found there, and although they are 18 or 20 feet high, they are, nevertheless, firm on their roots.[AO]Trees are met with in almost every morass, bog, and marsh, in Somerset, Chester, Lancaster, and Stafford. There are some places where trees are found under the earth, which have been cut, sawed, squared, and worked by the labour of man; and even wedges and saws have likewise been found by them. Between Birmingham and Bromley, in the county of Lincoln, there are lofty hills of fine light sand, which the rain and windsweep away, leaving uncovered the roots of large willow trees, on which the impression of the axe is exceedingly plain. These hills, without doubt, have been formed like downs, by the accumulation of sand, which the waters of the sea has brought there and deposited at different periods. A great number of these subterraneous trees are also found in the marshy lands of Holland, Friesland, and near Groningen, from whence the turfs which they burn are dug.

[AN]See Philosophical Transactions, No. 228.

[AO]See Ray's Discourses, page 232.

In the earth are found trees of almost every kind, as willows, oaks, firs, aspins, beach, yew, ash, hawthorn, &c. In the fens of Lincoln, along the river Ouse, and in Hatfield-Chace, in the county of York, these trees are as straight as we see them in a forest. The oaks are very hard and used in buildings; they are said to last a long time, but which I must doubt, as all trees that are dug out of the earth, at least all those which I have seen, whether oak or others, lose, in drying, all the solidity, which they appeared to have at first. The ash is tender, and soon crumbles to dust. There are many trees which have clearly been shaped and sawed by men, and the hatchets, sometimes found near them, resemble, in form, the knivesanciently used in sacrifices. Besides trees, nuts, acorns, &c. are met with in great quantities, in many other fenny parts of England and Ireland, as well as the morasses of France, Sweden, Savoy, and Italy.[AP]

[AP]See Transactions Philosophical Abridg. Vol. IV, page 218, &c.

In the city of Modena, and four miles round, whatever part of the earth is dug, to the depth of sixty-three feet, and then bored five more with an auger, the water springs out with such great force, that the well is filled instantly; and this water continues always the same, neither diminishing nor increasing by rain nor draught. What is more remarkable in this ground, when we reach the depth of fourteen feet, we find the ruins of an ancient town, as paved streets, houses, different pieces of mosaic work, &c. After this is a very solid ground, which appears to have never been stirred; yet below it we find a moist earth mixed with vegetables; and at twenty-six feet entire trees, as filberds with nuts thereon, and a great quantity of branches and leaves. At twenty-eight feet is a stratum of chalk mixed with shells, and this bed is eleven feet in thickness; after this we again meet with vegetables; and so on alternativelyto the depth of sixty-three, feet, when there is a bed of sand mixed with gravel and shells, like those formed on the coasts of the Italian sea; these successive beds are always met with in the same order, wheresoever it has been dug, and very often the auger meets with large trunks of trees, which the workmen bore through with much labour. Bones of animals, coals, flint, and pieces of iron are also found. Ramazzini, who relates these circumstances, thinks that the gulph of Venice formerly extended beyond Modena, and, that by the sediments of rivers in the course of time, assisted perhaps by the inundations of the sea, this ground has been formed.

I shall no longer dwell on the varieties in the formation of modern strata, it suffices to have shewn that they have been produced by no other causes than the running and stagnate waters, which are upon the surface of the earth, and that they are neither so hard nor solid as the ancient strata which are formed under the waters of the sea.

ARTICLE XIX.

OF THE CHANGES OF LAND INTO SEA AND SEA INTO LAND.

By what has been said in the ArticlesI,VII,VIII, andIX, it appears that great and general changes have happened to the terrestrial globe; and it is as certain, from what we have related in other articles, that the surface of the earth has undergone particular alterations. Although the order, or succession, of these particular alterations is not perfectly known, yet we are acquainted with the principal causes; we can even distinguish their different effects; and if we could collect all the facts, which Natural and Civil History furnishes on the subject of the revolutions which have happened to the surfaceof the earth, we do not doubt but that the Theory of the Earth which we have, laid down would receive additional support.

One of the principal causes of these alterations is the motion of the sea; a motion it has endured from the earliest ages; for since the sun, moon, earth, waters, air, &c. have existed from the time of the creation, the effects of the tides, the motion of the sea from east to west, as well as that of the winds and currents, must have been felt for the same space; and if even we should suppose the axis of the globe had formerly another inclination, and that the continents, as well as the sea, had another disposition, it does not destroy the motion of flux and reflux, nor alter the cause and effects of the winds: it is sufficient that the immense quantity of waters, which fill the vast space of the sea, is found in some part on the globe of the earth, for wherever they had been collected they would have still been subject to the same motions, and produced similar effects.

When it was once supposed that our continent was formerly the bottom of the sea, there was soon no doubt remaining thereon. The devastations of the sea, which are every where to be met with; the horizontal situation of thestrata of the earth; and the correspondence of hills and mountains, appear as so many convincing proofs; for by examining the plains, vallies, and hills, we clearly perceive that the surface of the earth has been formed by the waters. It is equally evident, when we look into the interior parts of the earth, that those stones which contain sea-shells, have been formed by the sediments of the waters, since the shells are found filled with the same matter as that which surrounds them; and lastly, by reflecting on the corresponding angles of opposite hills, we cannot doubt that their directions are the works of the currents of the sea. It is true, that since the earth has been left uncovered, the original form of the surface has been constantly changing; the mountains have diminished in height; the plains have been elevated; the angles of hills become more obtuse; many matters washed away by floods, or rivers, have taken a round shape; beds of gravel, soft stone, &c. have been formed; but the essential matter is still remaining, the ancient form is still apparent, and I am persuaded that all the world may be convinced by their own inspection of what has been advanced on this subject; and whoever attends to the observations and proofs Ihave given, will not doubt, the earth was formerly covered by the waters of the sea, and that it is the currents of the sea which have given to the surface of the earth, the form we at present perceive.

The principal motion of the sea is, as we have already observed, from east to west. It also appears that the sea has gained above 500 leagues of ground on the eastern coasts of both the old and new continents; for the proofs of which we refer to those given inArticle XI. and shall only add thereto, that all straits which join two seas, are directed from east to west; the straits of Magellan, Frobisher, of Hudson, of Ceylon, and those of the seas of Corea and Kamtschatka have all this direction, and appear to have been formed by the currents of the waters, which being impelled from east to west, opened these passages in the same direction, and in which they preserve a more considerable motion than in any other; for in these straits there are high and violent tides, whereas in those situated on the western coasts, like that of Gibraltar, Sund, &c. the motion of the tides is almost insensible.

The inequalities of the bottom of the sea change the direction of the water's motion;they have been successively produced by the sediments of the water, and by matters transported by the tides or other motions; for we do not consider the motion of the tides as the sole cause of those inequalities, but only as the principal and first, because it is the most constant and acts without interruption; the action of the winds is another cause; the action of which beginning at the surface, extends to considerable depths, as is plain from the matters that are loosened and thrown up by a storm from the bottom of the sea, and which never happens but in tempestuous weather.

We have already mentioned that between the tropics, and even some degrees beyond them, an east wind continually blows; this wind, which contributes to the general motion of the sea from east to west, is as ancient as the flux and reflux, since it depends on the rarefaction of the air, produced by the heat of the sun. Here then are two united causes of motion, the greatest of which is near the equator. The first, the tides which are more sensibly felt in southern latitudes: and the second, the east wind which blows continually in the same climates. These two causes have concurred, ever since the formation of the globe, to produce a motion in thewaters from east to west, and to agitate them more in that part of the globe than in all the rest. It is for this reason that the greatest inequalities of the surface of the globe are found between the tropics. The part of Africa, comprehended between these two circles, is only a group of mountains whose different chains extend for the most part from east to west, as is evident from the direction of the great rivers of this part of the world; it is the same with those parts of Asia and America which are comprised between the tropics.

From the combination of the general motion of the sea from east to west, with the flux and reflux of the currents, and the winds, an infinite number of different effects has resulted, both on the bottom of the sea, and on the coasts. Varenius says, it is very probable that the gulphs and straits have been formed by the reiterated efforts of the ocean against the land; that the Mediterranean sea, the gulphs of Arabia, Bengal, and Cambay, have been formed by the eruption of the waters, as well as the straits between Sicily and Italy, between Ceylon and India, between Greece and Eubœa, and that it is the same with respect to the straits of the Manillas, Magellan, &c. that one proof ofthese eruptions, and that the sea has forsaken different lands is, that but few islands are to be met with in the great seas, and never a great number of islands close to each other; that in the immense space occupied by the Pacific sea, not above two or three small islands are to be found towards the middle of it; that in the vast Atlantic ocean, between Africa and the Brazils, we only find the small islands of St. Helena and Ascension; but that all islands are near the great continents, as those of the Archipelago, near the continents of Europe and Asia, the Canaries, near Africa, all the islands of the Indian sea, near the eastern coast of Asia; the Antille islands, close to that of America, and that only the Azores lie at any great distance in the sea between Europe and America.

The inhabitants of Ceylon say, that their island was separated from the peninsula of India by an eruption of the ocean; and this popular tradition is very probable. It is also imagined the island of Sumatra has been separated from the continent, and the great number of shoals and sand banks are a strong proof of it. The Malabars assert, that the Maldivian islands formed a part of the continent of India, and in general it may be reasonably supposed that all theeastern islands have been divided from the continents by eruptions of the ocean.[AQ]

[AQ]See Varenius Geography, page 203, 217, and 220.

There is an appearance that formerly the island of Great Britain was part of the continent, and that England was joined to France; the similarity of the stones on the two coasts, and the narrowness of this strait seem plainly to indicate it. By supposing, says Dr. Wallis, "that England formerly communicated with France, by an isthmus between Dover and Calais, it must follow that the sea would be carried against both sides of it with great violence by the tides twice in every twenty-four hours, the German ocean, which is between England and Holland, striking of it on the eastern side, and that of France on the west, would be sufficient in time to wear away so narrow a neck of land, as we have supposed. The tides acting with great violence, not only against this isthmus but also against the coasts of France and England, must have washed away a great quantity of sand, earth, and clay, from every part against which the sea was forced: but, being stopt in its course, it would not deposite, as might be supposed, their sediments against this isthmus, but transported them into the great plain that nowforms Romney Marsh, which is eight miles long by four broad; for whosoever has seen this plain, cannot doubt but that it was formerly covered with the sea, as it would be still overflowed by spring tides if it was not for the Dikes of Dimchurch."

The German sea must have acted in the same manner against this isthmus, and the coasts of England and Flanders would convey its sediments into Holland and Zealand, the ground of which, though formerly covered with water, is now forty feet above. On the coast of England, the German sea must have filled up that large valley, where the river Stour actually flows for more than 20 miles, beginning at Sandwich, passing Canterbury, Chatham, Chilham as far as Ashford. At this place the ground is much higher than it was formerly, since at Chatham the bones of an hippopotamus were found seventeen feet deep in the earth, together with anchors and marine shells.

It is very probable the sea may form new land, by bringing and depositing, at particular places, sand, earth, mud, &c. for in the island of Orkney, which is adjacent to Romney Marsh, there was a tract of low land continuallyin danger of being inundated by the river Rother; but in less than 60 years this ground has been considerably elevated by quantities of earth and mud being brought thither every tide, and the channel through which it enters, in less than fifty years has deepened so much as to admit of the reception of large vessels, whereas at that time it was a ford over which people might pass.

In this manner, the sand bank was formed which extends obliquely from the coast of Norfolk to that of Zealand. This bank forms that part where the tides of the German and French sea meet, since the isthmus has been broken, and where the earth and sand are deposited which are washed away from the coasts; nor is it by any means improbable but that in the course of time this bank may become an isthmus.[AR]

[AR]See Abridgment of Philosophical Transactions, vol. II. page 227.

There is a great appearance, says Ray, that the island of Great Britain was formerly joined to France, and formed part of that continent: but it is not known whether its separation was caused by an earthquake, an eruption of the ocean, or by the labour of man; but that thisisland formed part of the continent is evident, from the rocks and coasts of both being of the same nature, composed of the same matters, and exactly of the same height; the length of the rocks, along these coasts, are also nearly the same, about six miles on either side. The little breadth of the channel, which in this part is not more than twenty-four English miles, and its shallowness, comparatively with the neighbouring sea, is another reason to suppose that England has been divided from France by accident. We may add to these proofs, that there were formerly wolves and bears in this island; it is not to be presumed that they could swim over, nor that men transported such destructive animals; for in general we find the noxious animals of the continent in the adjacent islands, and never in those which are separated from them by a great distance; as the Spaniards remarked when they landed in America.[AS]

[AS]See Ray's Discourses, page 208.

In the reign of Henry I. King of England, a great inundation happened by an eruption of the sea in part of Flanders. In 1446 by a like eruption 10,000 persons were drowned in the territory of Dordrecht, and more than100,000 round Dullart, Friezeland, and in Zealand. In these last two provinces upwards of 300 villages were overflowed; the tops of their towers and steeples are still to be seen rising out of the water.

From the coasts of France, England, Holland and Germany, the sea has retreated in many parts. Hubert Thomas relates, in his description of Liege, that the sea formerly surrounded the walls of the city of Tongres, which is now more than 35 leagues distant from it; this he proves by many eligible reasons, and, among others, he says; that in his time the iron rings, to which the ships were moored, were to be seen remaining in the walls. We may likewise look on as lands deserted by the sea, the fens of Lincoln in England, Provence in France, and which has also very considerably retreated from the mouth of the Rhone since the year 1665. In Italy a considerable tract of land has been gained at the mouth of the Arno; and Ravenna, formerly a sea-port, is no longer a maritime town. Holland appears to be an entire new country, where the surface of the earth is almost on a level with the sea, although the land is considerably elevated by the daily deposit of mudand earth from the Rhine, Maese, &c. for it was formerly computed that the ground of Holland was, in many places, 50 feet lower than the bottom of the sea.

It is asserted, that in the year 860, a furious tempest drove on the coast so great a quantity of sand that it shut up the mouth of the Rhine, near the Cat, and that this river inundated the whole country, tore up trees and houses, and, at last, emptied itself into the channel of the Maese. In 1421 another inundation separated the town of Dordrecht from the main land, submerged 72 villages, many castles, and drowned 100,000 souls, beside a great number of cattle. The dyke of Yssel was broken in 1638 by the ice brought down by the Rhine, which, having shut up the passage of the water, made an opening of some fathoms, and a great part of the province was overflowed before the breach could be repaired. In 1682 there was a similar inundation in the province of Zealand, which destroyed upwards of 30 villages, and drowned a considerable number of people and cattle, from their being surprised by the waters in the night. It was a fortunate circumstance for Holland that asouth wind opposed the inroad of the sea, for it was so greatly swelled that the water was 18 feet higher than the highest ground of the province.[AT]

[AT]See the Historical Voyages of Europe, volV.page 70.

At Hithe, in the county of Kent, the harbour has filled up in defiance of every expence and precaution that was made to prevent it. A surprising number of sea-shells, &c. are met with for several miles round, which were formerly heaped together, and which are now covered by earth, and are beautiful meadows. On the other side the sea has gained in several places, as for instance, the Goodwin Sands, which was an estate belonging to an Earl of that name, but at present is no more than sand covered by the waters of the sea: thus the sea in many places gains on the land and loses in others, according to the different situation of the coasts, and other circumstances.[AU]

[AU]See Abridg. Philosophical Trans. vol.IV.p. 234.

On Mount Stella, in Portugal, is a lake in which the wrecks of ships have been found, notwithstanding this mountain is more than 12 leagues from the sea.[AV]Sabinius, in his Commentarieson Ovid's Metamorphoses, says, that in the year 1460 a ship, with its anchors, was found in a mine of the Alps.

[AV]See Gordon's Geography, page 149.

It is not in Europe alone we meet with these vicissitudes of land into sea and sea into land; other parts of the world might furnish more remarkable, and in a greater number, if investigated with precision.

Calecut was formerly a famous city and the capital of a kingdom of that name; at present it is only a trifling town, meanly built, and but thinly inhabited: the sea, which for a century has gained greatly on this coast, has overflowed the greatest part of the old city, with a beautiful fortress of stone which was therein. Vessels at present moor on their ruins, and the port is filled with a great number of shoals, and on which ships are frequently wrecked.[AW]

[AW]See Letters Edifiantes Recueil 11. page 187.

The province of Jucatan, a peninsula in the gulph of Mexico, was formerly a part of the sea. This neck of ground extends 100 leagues in length, and is not more than 25 leagues at its greatest breadth. The air is perfectly hot and moist. Although there are neither rivulets nor rivers throughout so long a space, the water is every where so nigh the surface as to furnishplenty; and, by opening the earth, so great a number of shells are found as to leave no doubt that this great extent may be regarded as a place which formerly was part of the sea.

The inhabitants of Malabar pretend that formerly the Maldivian islands were attached to the Indian continent, and that the violence of the sea has divided them from it. The number of these islands is so great, and some of the channels, which separate them, are so narrow, that the boltsprits of vessels which pass them tear off the leaves of the trees on each side, and in some places an active man, by holding by the branch of a tree, may leap into another island.[AX]

[AX]See the Dutch Travels to the East-Indies, page 274.

The cocoa-trees, which are at the bottom of the sea, is a proof that the Maldivians were formerly part of the continent: cocoa-nuts are often detached from them and thrown on the shore by a storm.

It is imagined that the island of Ceylon was formerly united to the continent, and that the currents, which are extremely rapid in many parts of India, have divided that as well as Rammanakoil, and many other islands.[AY]However,it is certain that the island of Ceylon has lost 30 or 40 leagues of ground towards the north-west side, which the sea has gained.

[AY]See the Dutch Travels to the East-Indies, vol.II.p. 486.

It appears that the sea has recently forsaken a great part of the projecting lands and islands of America. We have just observed, that the ground of Jucatan is filled with shells. It is the same with the low lands of Martinico and the other Antille islands. The inhabitants have termed the earth below the surface lime, because they make their lime with these shells, considerable banks of which are found immediately under the vegetable earth. In the new voyages to the islands of America it is said, "lime, which is found in the land of Guadaloupe, when the earth is turned up, is of the same kind as that drawn out of the sea, the reason of which is difficult to be assigned. Might it not be possible, that all the extent of ground, which composes this island, was, in former times, only a high ground filled with lime-plants, which having grown and filled the void spaces that were occupied by the water, have raised up the ground, obliged the water to retire, and leave all the superficies dry? This conjecture, as extraordinary as at first it may appear, has, nevertheless, nothing impossiblein it; and if the people who reside there were to dig in different parts of the earth they would discover what the real soil is, and by that means destroy or strengthen my conjecture."

There are some lands which are sometimes covered with water and sometimes uncovered, as many islands in Norway, Scotland, Maldivias, the gulph of Cambaya, &c. The Baltic has, by little and little, gained a great part of Pomerania, and covered and destroyed the famous port of Vineta. So likewise the sea of Norway has projected into the continent, and formed many small islands. The German sea has projected into Holland near Cat, insomuch that the ruins of an ancient citadel of the Romans, which was formerly on the coast, are now very far in the sea. The marshy grounds in the Isle of Ely, in England, and those in Provence, in France, are, on the contrary, as we have observed, land which the sea has abandoned. Downs have been formed by the sea-winds, which have thrown and accumulated earth, sand, shells, &c. on the shore. For example, on the western coast of France, Spain, and Africa, durable and violent westerly winds reign,which impel the waters towards the shore with great impetuosity, and on which coasts downs are very frequent. In the like manner the easterly winds, when they remain any long time, so strongly drive the waters from the coasts of Syria and Phœnicia that the chain of rocks, which are covered with water during the westerly winds, are left quite dry. Thus downs are never composed of stone, or marble, like mountains formed in the bottom of the sea, because they have not been long enough under the water. In our discourse on minerals we shall shew that the sea possesses the power of petrifaction, and that the stones formed in the earth are quite different from those formed in the sea.

When I had just finished my Theory of the Earth, which I composed in 1744, I received from Mons. Barrere, his dissertation on the origin of figured stones, and I was pleased to find myself of the same opinion with this able naturalist, on the subject of the formation of downs, and the time the water remained on the earth which we inhabit; he recounts many alterations which have happened to the sea coasts: "Aiguis-mortes, which is now more than a league and a half from the sea, wasa port in the time of St. Louis: Psalmodi was an island in 815, and at present it is inland two leagues from the sea. It is the same with respect to Maguelone. The greatest part of the vineyards of Agde, was forty years ago covered by the sea: and in Spain the sea has considerably retreated within a short space of time from Blancs, Badalona, the mouth of the river Vobregat, Cape Tortosa, along the coasts of Valentia, &c.

"The sea may form hills and mountains in many different manners; first, by the transportations of earth, sand, and shells, from one place to another; secondly, by depositing sediments, consisting of small particles detached from the coasts and bottom, and which it might have transported from a considerable distance; and lastly, by sand, mud, and other articles, which the sea winds often drive against coasts, downs and hills may be produced, which the water forsaking, by degrees, become parts of the continent." The downs of Flanders and Holland are of this kind, being only hills composed of sand and shells, which the sea winds have driven towards the land. Mons. Barrere quotes another example which merits a place in this work. "Thesea, by its motion, detaches from its bottom an infinity of plants, shells, slime, and sand, which the waves and winds continually drive towards the shore. Now, all these different operations must continually form new strata, elevate the beds of earth, gradually raising downs and hills, retrenching the bounds of the ocean, and by that means extending the lands on the continents."

"It is visible that new strata have been successively formed by the same reiterated motion of the waters from the deposition of sediments and other constant causes from time immemorial; of which I find strong proofs in the different beds of fossils, shells, and other marine productions found in Roussillon near the village of Naffiac, about seven or eight leagues from the sea; these beds of shells which are inclined from the west to the east, and in different angles, are separated from each other by banks of sand and earth, are sometimes from one and a half to two or three feet in thickness. They appear as if sprinkled with salt in dry weather, and form together hillocks from twenty-five to thirty fathoms in height: now a long chain of hills of such an height can only be formed gradually, and at different successions of time.Such might be the effect of an universal deluge, which must have disturbed all nature; but which could not have given a regular form to these different beds of fossil shells, but would have jumbled them together without any order or regularity."

On this subject I am perfectly of the same opinion as M. Barrere, excepting as to the formation of mountains, which I cannot agree ought to be entirely attributed to the causes which occasion the ocean to gain upon the land on some parts, and lose it upon others. As I am, on the contrary, of opinion, I could produce many convincing arguments to prove that most of the eminencies seen on the surface of the earth have been actually formed in the sea itself. First, because they have a correspondence of saillant and returning angles, which necessarily implies the cause we have assigned, that is, the motion of the currents. Secondly, because downs and hills, which are formed by the materials that the sea brings on its shores, are not composed of marble and hard stone, like common hills; the shells also in the former are generally only fossils, whereas in the latter, the petrifaction is compleat; besides the beds of earth are not so horizontalin downs as in the hills composed of marble and hard stone, but are more or less inclined, as in the hills of Naffiac, whereas in the hills and mountains, formed under the water by the sediment of the sea, the strata are always parallel, and very often horizontal, and the shells and other marble are entirely petrified. I have no doubt of proving that marble and other calcinable matters, which are almost all composed of madrepores, astroites, and shells, have acquired their hardness and perfection at the bottom of the sea; on the contrary, gravel, soft stones, incrustations, stalactites, &c. which are also calcinable and found in the earth, and formed since our continent has been discovered, cannot acquire this degree of hardness and petrifaction which marble or hard stones have.

In the history of the French Academy for 1708, may be seen the observations of Saulmon, on the subject of the galets found in many places. These galets are round and flat flints very smooth, and which are cast on the shores by the sea. At Bayeux, and at Prutel, which are a league from the sea, we find them in digging wells or pits. The mountains of Bonneuil, Broie, and Quesny, which are eighteen leaguesfrom the sea, are all covered with galets; they are also found in the valley of Clermont in Beauvois. M. Saulmon likewise relates, that a hole, 16 feet deep, was bored horizontally into the beach of Tresport, which is soft earth, and that it entirely disappeared in 30 years: so that if the sea always encroaches alike, it would gain half a league in 12,000 years.

The motions of the sea are therefore the principal causes of the alterations which have happened, and which daily happen on the surface of the globe. But there are many, other causes, which, though less considerable, contribute to those changes. Running waters, rivers, streams, the melting of snow, torrents, frosts, &c. have occasioned many changes; the rains have diminished the height of mountains; rivers and rivulets have raised plains, and stopped up the sea at their mouths; the melting of snow, and torrents, have dug hollows in vallies; and the frosts have split rocks and separated them from their former stations. We might quote an infinity of examples on the alterations these causes have occasioned. Varenius says, that rivers convey into the sea great quantities of earth, which they deposit at a greater or less distance from the coasts, accordingto the rapidity of their currents; these earths fall to the bottom of the sea, and, at first, form those small banks which daily encrease, become shoals, and, at last, form islands, which are fertile and inhabitable. This is the manner in which the islands of the Nile are formed, as well as those of St. Laurence, the Isle of Landa, situate on the coast of Africa, near the mouth of the river Coanza, the island of Norway, &c.[AZ]To these may be added the island of Trong Ming, at China, which has been gradually formed by the earth that the river Nankin has brought and deposited it at its mouth. This island is more than 20 leagues long by five or six broad.[BA]

[AZ]See Varenni Geograph. page 214.

[BA]See Letters Edifiantes, Recueil xi. page 234.

The Po, Trento, Athesis, and other rivers of Italy, bring with them great quantities of earths into the lakes of Venice, especially during the time of inundations, which, in course of time, must fill them up. In many places they are now dry at low water, and, excepting the canals, which are kept up at a great expence, have no depth of water.

At the mouths of the Nile, the Ganges, the Indus, the Plata, the Nankin, and of manyother rivers, the earth and sand deposited form considerable banks. Loubere, in his Voyage to Siam, says, that the banks of sand and earth daily increase at the mouths of the great rivers of Asia, insomuch that the navigation of them becomes every day more difficult, and will one day be impassable. The same remark may be made of the large rivers of Europe, and particularly of the Wolga, which has more than 70 mouths in the Caspian sea, and of the Danube, which has seven in the Black sea, &c.

As it seldom rains in Egypt the regular inundations of the Nile proceed from the torrents which fall therein from Ethiopa. These annually bring with them great quantities of mud, which they not only deposit on the land of Egypt but even throw to a considerable distance in the sea, and thus lay the foundation of a new land, which, in the course of time, arises therefrom; for, by sounding with the lead, we find, at more than 20 leagues distance from the coast, the mud of the Nile at the bottom of the sea, and which is every year increasing. Lower Egypt, where[BB]Dela at present stands, was formerly a gulph of thesea. Homer tells us that the island of Pharos was 24 hours voyage from Egypt, and at present it is almost contiguous to it. The soil of Egypt has not the same depth of good ground throughout its extent, it lessens as we approach the sea. Near the borders of the Nile there is sometimes near thirty feet depth of good earth, whereas at the extremity of the inundation there is scarcely more than seven inches.[BC]The town of Damietta, at present more than 10 miles from the sea, in 1243 was a sea-port. The town of Fooah, which, 300 years ago, was situate at the mouth of the Canopic, a branch of the Nile, is now more than seven leagues from it. Within 40 years the sea has retreated half a league from before Rosetta and Idern.

[BB]See Diodorus de Suc, lib. 3. Aristotle, lib. 1. of Meteors, h. xiv. Herodotus, f. 4, 5, &c.

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