able experience they find that, instead of going | time after a dolphin was caught in the Red sea, forward, they have been all the time receding. The business of currents, therefore, makes a considerable article in navigation; and the direction of their stream, and their rapidity, has been carefully set down. This some do by the observation of the surface of the current; or by the driving of the froth along the shore; or by throwing out what is called the log-line, with a buoy made for that purpose, and by the direction and motion of this, they judge of the setting and the rapidity of the current. and quickly known by the ring to be the same that had been taken in the Mediterranean before. Such, however, as have not been willing to found their opinions upon a story, have attempted to account for the disposal of the waters of the Mediterranean by evaporation. For this purpose they have entered into long calculations upon the extent of its surface, and the quantity of water that would be raised from such a surface in a year. They then compute how much water runs in by its rivers and straits in that time; These currents are generally found to be most and find, that the quantity exhausted by evaporaviolent under the equator, where indeed all the tion, greatly exceeds the quantity supplied by motions of the ocean are most perceivable. Along rivers and seas. This solution, no doubt, would the coasts of Guinea, if a ship happens to over- be satisfactory, did not the ocean, and the Euxine, shoot the mouth of any river it is bound to, the evaporate as well as the Mediterranean; and as current prevents its return; so that it is obliged these are subject to the same drain, it must folto steer out to sea, and take a very large com-low, that all the seas will in this respect be upon pass, in order to correct the former mistake. a par; and therefore, there must be some other These set in a contrary direction to the general cause for this unperceived drain, and continual motion of the sea westward; and that so strongly, supply. This seems to be satisfactorily enough that a passage which, with the current, is made accounted for by Dr. Smith, who supposes an in two days, is with difficulty performed in six under current running through the straits of weeks against it. However, they do not extend Gibraltar, to carry out as much water into the above twenty leagues from the coast; and ships ocean, as the upper current continually carries going to the East Indies, take care not to come in from it. To confirm this, he observes, that within the sphere of their action. At Sumatra, nearer home, between the North and South the currents, which are extremely rapid, run Foreland, the tide is known to run one way at from south to north; there are also strong cur- top, and the ebb another way at bottom. This rents between Madagascar and the Cape of Good double current he also confirms by an experiHope. On the western coasts of America, the ment communicated to him by an able seaman, current always runs from the south to the north, who being with one of the king's frigates in the where a south wind, continually blowing, most Baltic, found he went with his boat into the probably occasions this phenomenon. But the mid-stream, and was carried violently by the curcurrents that are most remarkable, are those rent; upon which a basket was sunk, with a continually flowing into the Mediterranean sea, large cannon-ball, to a certain depth of water, both from the ocean by the straits of Gibraltar, which gave a check to the boat's motion: as the and at its other extremity, from the Euxine sea basket sunk still lower, the boat was driven, by by the Archipelago. This is one of the most the force of the water below, against the upper extraordinary appearances in nature; this large current; and the lower the basket was let down, sea receiving not only the numerous rivers that the stronger the under current was found, and fall into it, such as the Nile, the Rhone, and the the quicker was the boat's motion against the Po, but also a very great influx from the Euxine upper stream, which seemed not to be above four sea on one part, and the ocean on the other. At fathom deep. From hence we may readily infer, the same time, it is seen to return none of those that the same cause may operate at the straits waters it is thus known to receive. Outlets run-of Gibraltar; and that while the Mediterranean ning from it there are none; no rivers but such seems replenishing at top, it may be emptying at as bring it fresh supplies; no straits but what bottom. are constantly pouring their waters into it: it The number of the currents at sea are imposhas, therefore, been the wonder of mankind in sible to be recounted, nor indeed are they always every age, how, and by what means, this vast known; new ones are daily produced by a variety concourse of waters are disposed of; or how this of causes, and as quickly disappear. When a sea, which is always receiving, and never return-regular current is opposed by another in a narrow ing, is no way fuller than before. In order to account for this, some have said, that the water was reconveyed by subterraneous passages into the Red sea. 4 There is a story told of an Arabian calif, who caught a dolphin in this sea; admiring the beauty of which, he let it go again, having previously marked it by a ring of iron. Some Kircher, Mund. Subt. vol. i. strait, or where the bottom of the sea is very uneven, a whirlpool is often formed. These were formerly considered as the most formidable obstructions to navigation; and the ancient poets and historians speak of them with terror; they are described as swallowing up ships, and dashing them against the rocks at the bottom: apprehension did not fail to add imaginary terrors to the description, and placed at the centre of the whirl timber, and shipping. No skill in the mariner, nor strength of rowing, can work an escape; the sailor at the helm finds the ship at first go in a current opposite to his intentions; his vessel's motion, though slow in the beginning, becomes every moment more rapid; it goes round in circles still narrower, and narrower, till at last it is dashed against the rocks, and instantly disappears: nor is it seen again for six hours; till the tide flowing, it is vomited forth with the same violence with which it was drawn in. The noise of this dreadful vortex still farther contributes to increase its terror, which, with the dashing of the waters and the dreadful valley, if it may be so called, caused by their circulation, makes one of the most tremendous objects in nature. pool a dreadful den fraught with monsters whose | come within the sphere of its violence, trees, howlings served to add new horrors to the dashings of the deep. Mankind at present, however, view these eddies of the sea with very little apprehension; and some have wondered how the ancients could have so much overcharged their descriptions. But all this is very naturally accounted for. In those times when navigation was in its infancy, and the slightest concussion of the waves generally sent the poor adventurer to the bottom, it is not to be wondered at that he was terrified at the violent agitations in one of these. When his little ship, but ill fitted for opposing the fury of the sea, was got within the vortex, there was then no possibility of ever returning. To add to the fatality, they were always near the shore; and along the shore was the only place where this ill-provided mariner durst venture to sail. These were, therefore, dreadful impediments to his navigation; for if he attempted to pass between them and the shore, he was sometimes sucked in by the eddy; and if he attempted to avoid them out at sea, he was often sunk by the storm. But in our time, and in our present improved state of navigation, Charybdis, and the Euripus, with all the other irregular currents of the Mediterranean, are no longer formidable. Mr. Addison, not attending to this train of thinking, upon passing through the straits of Sicily, was surprised at the little there was of terror in the present appearance of Scylla and Charybdis; and seems to be of opinion, that their agitations are much diminished since the times of antiquity. In fact, from the reasons above, all the wonders of the Mediterranean sea are described in much higher colours than they merit, to us who are acquainted with the more magnificent terrors of the ocean. The Mediterranean is one of the smoothest and most gentle seas in the world; its tides are scarcely perceivable, except in the gulf of Venice, and shipwrecks are less known there than in any other part of the world. It is in the ocean, therefore, that these whirlpools are particularly dangerous, where the tides are violent, and the tempests fierce. To mention only one, that called the Maelstroom, upon the coasts of Norway, which is considered as the most dreadful and voracious in the world. The name it has received from the natives, signifies the navel of the sea; since they suppose that a great share of the water of the sea is sucked up and discharged by its vortex. A minute description of the internal parts is not to be expected, since none who were there ever returned to bring back information. The body of the waters that form this whirlpool, are extended in a circle above thirteen miles in circumference. In the midst of this stands a rock, against which the tide in its ebb is dashed with inconceivable fury. At this time it instantly swallows up all things that 5 Kircher, Mund. Subt. vol. i. p. 156. CHAP. XVII. OF THE CHANGES PRODUCED BY THE SEA UPON THE EARTH. FROM what has been said, as well of the earth as of the sea, they both appear to be in continual fluctuation. The earth, the common promptuary that supplies subsistence to men, animals, and vegetables, is continually furnishing its stores to their support. But the matter which is thus derived from it, is soon restored, and laid down again to be prepared for fresh mutations. The transmigration of souls is, no doubt, false and whimsical; but nothing can be more certain than the transmigration of bodies: the spoils of the meanest reptile may go to the formation of a prince; and, on the contrary, as the poet has it, the body of Cæsar may be employed in stopping a beer-barrel. From this, and other causes, therefore, the earth is in continual change. Its internal fires, the deviation of its rivers, and the falling of its mountains, are daily altering its surface; and geography can scarcely recollect the lakes and the valleys that history once described. But these changes are nothing to the instability of the ocean. It would seem that inquietude was as natural to it as its fluidity. It is first seen with a constant and equable motion going towards the west; the tides then interrupt this progression, and for a time drive the waters in a contrary direction; beside these agitations, the currents act their part in a smaller sphere, being generally greatest where the other motions of the sea art least; namely, nearest the shore; the winds also contribute their share in this universal fluctuation; so that scarcely any part of the sea is wholly seen to stagnate. Nil enim quiescit, undis impellitur unda, As this great element is thus changed, and continually labouring internally, it may be readily supposed that it produces correspondent changes upon its shores, and those parts of the earth subject to its influence. In fact, it is every day making considerable alterations, either by overflowing its shores in one place, or deserting them in others; by covering over whole tracts of country that were cultivated and peopled, at one time; or by leaving its bed to be appropriated to the purposes of vegetation, and to supply a new theatre for human industry at another. the sea. Here also, the sea is deep, turbulent, and stormy; so that it requires great force in the shore to oppose its violence. In many parts of the world, and particularly upon the coasts of the East Indies, the shores, though not high above water, are generally very deep, and consequently the waves roll against the land with great weight and irregularity. This rising of the waves against the shore, is called by mariners the surf of the sea; and in shipwrecks is generally fatal to such as attempt to swim on shore. In this case no dexterity in the swimmer, no float he can use, neither swimming-girdle nor cork-jacket, will save him; the weight of the superincumbent wave breaks upon him at once, and crushes him with certain ruin. Some few of the natives, however, have the art of swimming and of navigating their little boats near those shores, where an European is sure of instant destruction. In places where the force of the sea is less violent, or its tides less rapid, the shores are gener In this struggle between the earth and the sea for dominion, the greatest number of our shores seem to defy the whole rage of the waves, both by their height and the rocky materials of which they are composed. The coasts of Italy, for instance,1 are bordered with rocks of marble of different kinds, the quarries of which may easily be distinguished at a distance from sea, and appear like perpendicular columns of the most beautiful kinds of marble, ranged along the shore. In general, the coasts of France, from Brest to Bour-ally seen to descend with a more gradual declivity. deaux, are composed of rocks; as are also those of Spain and England, which defend the land, and only are interrupted, here and there, to give an egress to rivers, and to grant the conveniences of bays and harbours to our shipping. It may in general be remarked, that wherever the sea is most violent and furious, there the boldest shores, and of the most compact materials, are found to oppose it. There are many shores several hundred feet perpendicular, against which the sea, when swollen with tides or storms, rises and beats with inconceivable fury. In the Orkneys,' where the shores are thus formed, it sometimes, when agitated by a storm, rises two hundred feet perpendicular, and dashes up its spray, together with sand and other substances that compose its bottom, upon land, like showers of rain. From hence, therefore, we may conceive how the violence of the sea, and the boldness of the shore, may be said to have made each other. Where the sea meets no obstacles, it spreads its waters with a gentle intumescence, till all its power is destroyed, by wanting depth to aid the motion. But when its progress is checked in the midst, by the prominence of rocks, or the abrupt elevation of the land, it dashes with all the force of its depth against the obstacle, and forms, by its repeated violence, that abruptness of the shore which confines its impetuosity. Where the sea is extremely deep, or very much vexed by tempests, it is no small obstacle that can confine its rage; and for this reason we see the boldest shores projected against the deepest waters; all lesser impediments having long before been surmounted and washed away. Perhaps of all the shores in the world, there is not one so high as that on the west of St. Kilda, which, upon a late admeasurement,3 was found to be six hundred fathoms perpendicular above the surface of 1 Buffon, vol. ii. p. 199. 2 Ibid. p. 191. 3 Description of St. Kilda. Over these, the waters of the tide steal by almost imperceptible degrees, covering them for a large extent, and leaving them bare on its recess. Upon these shores, as was said, the sea seldom beats with any great violence, as a large wave has not depth sufficient to float it onwards, so that here only are to be seen gentle surges making calmly towards land, and lessening as they approach. As the sea, in the former description, is generally seen to present prospects of tumult and uproar, here it more usually exhibits a scene of repose and tranquil beauty. Its waters which, when surveyed from the precipice, afforded a muddy, greenish hue, arising from their depth and position to the eye, when regarded from a shelving shore, wear the colour of the sky, and seem rising to meet it. The deafening noise of the deep sea, is here converted into gentle murmurs; instead of the water's dashing against the face of the rock, it advances and recedes, still going forward, but with just force enough to push its weeds and shells, by insensible approaches, to the shore. There are other shores, beside those already described, which either have been raised by art, to oppose the sea's approaches, or, from the sea's gaining ground, are threatened with imminent destruction. The sea's being thus seen to give and take away lands at pleasure, is, without question, one of the most extraordinary considerations in all natural history. In some places it is seen to obtain the superiority by slow and certain approaches; or to burst in at once, and overwhelm all things in undistinguished destruction; in other places it departs from its shores, and where its waters have been known to rage, it leaves fields covered with the most beautiful verdure. The formation of new lands by the sea's con 4 Newton's Optics, pp. 163-167. tinually bringing its sediment to one place, and by the accumulation of its sands in another, is easily conceived. We have had many instances of this in England. The island of Oxney, which is adjacent to Romney-marsh, was produced in this manner. This had for a long time been a low level, continually in danger of being overflown by the river Rother; but the sea, by its depositions, has gradually raised the bottom of the river, while it has hollowed the mouth: so that the one is sufficiently secured from inundations, and the other is deep enough to admit ships of considerable burthen. The like also may be seen at that bank called the Dogger-sands, where two tides meet, and which thus receives new increase every day, so that in time the place seems to promise fair for being habitable earth. On many parts of the coasts of France, England, Holland, Germany, and Prussia, the sea has been sensibly known to retire. Hubert Thomas asserts, in his description of the Country of Liege, that the sea formerly encompassed the city of Tongres, which, however, is at present thirty-five leagues distant from it: this assertion he supports by many strong reasons; and, among others, by the iron rings fixed in the walls of the town, for fastening the ships that came into the port. In Italy there is a considerable piece of ground gained at the mouth of the river Arno; and Ravenna, that once stood by the sea-side, is now considerably removed from it. But we need scarcely mention these, when we find that the whole republic of Holland seems to be a conquest upon the sea, and in a manner rescued from its bosom. The surface of the earth, in this country, is below the level of the bed of the sea; and I remember, upon approaching the coast, to have looked down upon it from the sea, as into a valley however, it is every day rising higher by the depositions made upon it by the sea, the Rhine, and the Meuse; and those parts which formerly admitted large men-of-war, are now known to be too shallow to receive ships of very moderate burthen. The province of Jucatan, a peninsula in the gulf of Mexico, was formerly a part of the sea. This tract, which stretches out into the ocean a hundred leagues, and which is above thirty broad, is everywhere, at a moderate depth below the surface, composed of shells, which evince that its land once formed the bed of the sea. In France, the town of Aigues Mortes was a port in the times of St. Louis, which is now removed more than four miles from the sea. Psalmodi, in the same kingdom, was an island in the year 815, but is now more than six miles from the shore. All along the coasts of Norfolk, I am very well assured, that in the memory of 5 It is supposed that there existed an isthmus between Great Britain and France, which is conceived to have been broken down by the sea, before the commencement of any accurate historical records respecting these islands.-ED. man the sea has gained fifty yards in some places, and has lost as much in others.8 Thus numerous, therefore, are the instances of new lands having been produced from the sea, which, as we see, is brought about two different ways; first, by the waters raising banks of sand and mud where their sediment is deposited: and, secondly, by their relinquishing the shore entirely, and leaving it unoccupied to the industry of man. But as the sea has been thus known to recede from some lands, so has it, by fatal experience, been found to encroach upon others; and probably these depredations on one part of the shore, may account for their dereliction from another; for the current which rested upon some certain bank having got an egress in some other place, it no longer presses upon its former bed, but pours all its stream into the new entrance; so that every inundation of the sea may be attended with some correspondent dereliction of another shore. However this be, we have numerous histories of the sea's inundations, and its burying whole provinces in its bosom. Many countries that have been thus destroyed, bear melancholy witness to the truth of history; and show the tops of their houses and the spires of their steeples, still standing at the bottom of the water. One of the most considerable inundations we have in history, is that which happened in the reign of Henry I., which overflowed the estates of the Earl Godwin, and forms now that bank called the Godwin Sands. In the year 1546, a similar irruption of the sea destroyed a hundred thousand persons in the territory of Dort; and yet a greater number round Dullart. In Friezland and Zealand there were more than three hundred villages overwhelmed; and their ruins continue still visible at the bottom of the water in a clear day. The Baltic sea has, by slow degrees, covered a large part of Pomerania; and, among others, destroyed and overwhelmed the famous port of Vineta. In the same manner, the Norwegian sea has formed several little islands from the mainland, and still daily advances upon the continent. The German sea has advanced upon the shores of Holland, near Catt; so that the ruins 8 "An extraordinary gain of land is described to have taken place at the head of the Red sea, the age of Herodotus. In his time, and down to that of isthmus of Suez having doubled in breadth since the Arrian, Heroopolis was on the coast, now it is as far distant from the Red sea as from the Mediterranean. Suez in 1541 received into its harbour the fleet bank. The country called Tehama, on the Arabian of Solyman II.; but it is now changed into a sandside of the gulf, has increased from three to six miles since the Christian era. Inland from the present ports are the ruins of more ancient towns, which were once on the sea-shore, and bore the same names. It is said that the blown sand from the deserts supplies some part of the materials of this new land, and that the rest is composed of shells and corals, of which the growth is very rapid."-Lyell's Geology. of an ancient citadel of the Romans, which was | earth in like manner. It has continued for some formerly built upon this coast, are now actually under water. To these accidents several more might be added; our own historians, and those of other countries, abound with them; almost every flat shore of any extent, being able to show something that it has lost, or something that it has gained from the sea." There are some shores on which the sea has made temporary depredations; where it has overflowed, and after remaining perhaps some ages, it has again retired of its own accord, or been driven back by the industry of man.10 There are many lands in Norway, Scotland, and the Maldivia islands, that are at one time covered with water, and at another free. The country round the isle of Ely, in the times of Bede, about a thousand years ago, was one of the most delightful spots in the whole kingdom; it was not only richly cultivated, and produced all the necessaries of life, but grapes also, that afforded excellent wine. The accounts of that time are copious in the description of its verdure and fertility; its rich pastures covered with flowers and herbage; its beautiful shades, and wholesome air. But the sea, breaking in upon the land, overwhelmed the whole country, took possession of the soil, and totally destroyed one of the most fertile valleys in the world. Its air, from being dry and healthful, from that time became most unwholesome, and clogged with vapours; and the small part of the country that, by being higher than the rest, escaped the deluge, was soon rendered uninhabitable, from its noxious vapours. Thus this country continued under water for some centuries: till at last the sea, by the same caprice which had prompted its invasions, began to abandon the 9 "The straits of Gibraltar are said to become gradually wider by the wearing down of the cliffs on each side at many points; and the current sets along the coast of Africa so as to cause considerable inroads in various parts, particularly near Carthage. Near the Canopic mouth of the Nile, at Aboukir, the coast was greatly devastated in the year 1784, when a small island was nearly consumed. By a series of similar operations, the old sites of the cities of Nicopolis, Taposiris, Parva, and Canopus, have become a sandbank. It frequently happens, where the sea is encroaching on a coast, that perpendicular cliffs of considerable height, composed of loose sand, supply, as they crumble away, large quantities of fine sand, which being in mid-air when detached, are carried by the winds to great distances, covering the land or barring up the mouths of estuaries. This is exemplified in Poole bay, in Hampshire, and in many points of the coast of Norfolk and Suffolk. But a violent wind will sometimes drift the sand of a seabeach, and carry it up with fragments of shells to great heights, as in the case of the sands of Barry, at the northern side of the estuary of the Tay, where hills of this origin attain the height of 140 feet. On the coast of France and Holland long chains of these dunes have been formed in many parts, and often give rise to very important geological changes, by damming up the mouths of estuaries, and preventing the free ingress of the tides, or free efflux of river water."-Lyell's Geology. 10 Buffon. vol. ii. p. 425. ages to relinquish its former conquests; and although the inhabitants can neither boast the longevity nor the luxuries of their former preoccupants, yet they find ample means of subsistence; and if they happen to survive the first years of their residence there, they are often known to arrive at a good old age. But although history be silent as to many other inundations of the like kind, where the sea has overflowed the country, and afterwards retired, yet we have numberless testimonies of another nature, that prove it beyond the possibility of a doubt: I mean those numerous trees that are found buried at considerable depths in places where either rivers or the sea have accidentally overflown. At the mouth of the river Ness, near Bruges, in Flanders, at the depth of fifty feet, are found great quantities of trees lying as close to each other as they do in a wood; the trunks, the branches, and the leaves, are in such perfect preservation, that the particular kind of each tree may instantly be known. About five hundred years ago, this very ground was known to have been covered by the sea; nor is there any history or tradition of its having been dry ground, which we can have no doubt must have been the case. Thus we see a country flourishing in ver| dure, producing large forests, and trees of various kinds, overwhelmed by the sea. We see this element depositing its sediment to a height of fifty feet; and its waters must, therefore, have risen much higher. We see the same, after it has thus overwhelmed and sunk the land so deep beneath its slime, capriciously retiring from the same coasts, and leaving that habitable once more, which it had formerly destroyed. All this is wonderful; and, perhaps, instead of attempting to inquire after the cause, which has hitherto been inscrutable, it will best become us to rest satisfied with admiration. At the city of Modena in Italy, and about four miles round it, wherever it is dug, when the workmen arrive at the depth of sixty-three feet, they come to a bed of chalk, which they bore with an auger five feet deep; they then withdraw from the pit before the auger is removed, and upon its extraction, the water bursts up through the aperture with great violence, and quickly fills this new-made well, which continues full, and is affected neither by rains nor droughts. But that which is most remarkable in this operation, is the layers of earth as we descend. At the depth of fourteen feet are found the ruins of an ancient city, paved streets, houses, floors, and different pieces of Mosaic. Under this is found a solid earth, that would induce one to think had never been removed; however, under it is found a soft oozy earth, made up of vegetables; and at twenty-six feet depth, large trees entire, such as walnut-trees, with the walnuts still sticking on 11 Buffon, vol. ii. p. 403. |