numberless others as little worthy of existence as themselves. But the motion of this great element effectually destroys the number of these viler creatures; its currents and its tides produce continual agitations, the shock of which they are not able to endure; the parts of the fluid rubbing against each other destroy all viscidities; and the ocean, if I may so express it, acquires health by exercise.

The most obvious motion of the sea, and the most generally acknowledged, is that of its tides. The element is observed to flow for certain hours, from south towards the north; in which motion or flux, which lasts about six hours, the sea gradually swells; so that entering the mouths of rivers, it drives back the riverwaters to their heads. After a continual flux of six hours, the sea seems to rest for a quarter of an hour; and then begins to ebb, or retire back again, from north to south for six hours more; in which time the waters sinking, the rivers resume their natural course. After a seeming pause of a quarter of an hour, the sea again begins to flow as before: and thus it has alternately risen and fallen, twice a-day, since the creation.

This amazing appearance did not fail to excite the curiosity as it did the wonder of the ancients. After some wild conjectures of the earliest philosophers, it became well known in the time of Pliny that the tides were entirely under the influence, in a small degree, of the sun; but in a greater of the moon. It was found that there was a flux and reflux of the sea in the space of twelve hours fifty minutes, which is exactly the time of a lunar day. It was observed that, whenever the moon was in the meridian, or, in other words, as nearly as possible over any part of the sea, that the sea flowed to that part and made a tide there; on the contrary, it was found that when the moon left the meridian the sea began to flow back again from whence it came, and there might be said to cbb. Thus far the waters of the sea seemed regularly to attend the motions of the moon. But as it appeared, likewise, that when the moon was in the opposite meridian as far off on the other side of the globe, there was a tide on this side also; so that the moon produced two tides-one by her greatest approach to us, and another by her greatest distance from us; in other words, the moon, in once going round the earth, produced two tides at the same time-one on the other part of the globe directly under her, and the other on the part of the globe directly opposite.

Mankind continued for several ages content with knowing the general cause of these wonders, hopeless of discovering the particular manner of the moon's operation. Kelper was the first who conjectured that attraction was the principal cause, asserting that the sphere of the moon's operation extended to the earth, and drew up its waters. The precise manner in which this is done was discovered by Newton.

The moon has been found, like all the rest of the planets, to attract and to be attracted by the earth. This attraction prevails throughout our whole planetary system. The more matter there is contained in any body, the more it attracts; and its influence decreases in proportion as the distance, when squared, increases. This being premised, let us see what must ensue upon supposing the moon in the meridian of any tract of the sea. The surface of the water immediately under the moon is nearer the moon than any other part of the globe is; and, therefore, must be more subject to its attraction than the waters any where else. The waters will, there fore, be attracted by the moon, and rise in a heap; whose eminence will be the highest where the attraction is greatest. In order to form this eminence, it is obvious that the surface, as well as the depths, will be agitated; that wherever the water runs from one part, succeeding waters must run to fill up the space it has left. Thus the waters of the sea, running from all parts to attend the motions of the moon, produce the flowing

of the tide; and it is high tide at that part wherever the the moon comes over it, or to its meridian.

But when the moon travels onward, and ceases to point over the place where the waters were just risen, the cause here of their rising ceasing to operate, they will flow back by their natural gravity into the lower parts from whence they had travelled; and this retiring of the waters will form the ebbing of the sea.

Thus the first part of the demonstration is obvious; since, in general, it requires no great sagacity to conceive that the waters nearest the moon are most attracted, or raised highest by the moon. But the other part of the demonstration, namely, how there come to be high tides at the same time, on the opposite side of the globe, and where the waters are farthest from the moon, is not so easy to conceive. To comprehend this, it must be observed, that the part of the earth and its waters that are farthest from the moon are the parts of all others that are least attracted by the moon: it must be observed, that all the waters, when the moon is on the opposite side of the earth, must be attracted by it in the same direction that the earth itself attracts them; that is, if I may so say, quite through the body of the earth, towards the moon itself. This, therefore, being conceived, it is plain that those waters which are furthest from the moon will have less weight than those of any. other part on the same side of the globe; because the moon's attraction, which conspires with the earth's attraction, is there least. Now, therefore, the waters farthest from the moon, having less weight, and being lightest, will be pressed on all sides by those that, having more attraction, are heavier: they will be pressed, I say, on all sides; and the heavier waters flowing in will make them swell and rise in an eminence directly opposite to that on the other side of the globe, caused by the more immediate influence of the moon.

In this manner, the moon, in one diurnal revolution, produces two tides; one raised immediately under the sphere of its influence, and the other directly opposite to it. As the moon travels, this vast body of waters rears upward, as if to watch its motions; and pursues the same constant rotation. However, in this great work of raising the tides the sun has no small share; it produces its own tides constantly every day, just as the moon does, but in a much less degree, because the sun is at an immensely greater distance. Thus there are solar tides. When the forces of these two great luminaries concur, which they always do when they are either in the same or in opposite parts of the heavens, they jointly produce a much greater tide than when they are so situated in the heavens as each to make peculiar tides of their own. To express the very same thing technically; in the conjunctions and oppositions of the sun and moon, the attraction of the sun conspires with the attraction of the moon-by which means the high spring-tides are formed. But in the quadratures of the sun and moon, the water raised by the one is depressed by the other; and hence the lower neap-tides have their production. In a word, the tides are greatest in the syzigies, and least in the quadratures.

This theory well understood, and the astronomical terms previously known, it may readily be brought to explain the various appearances of the tides, if the earth were covered with a deep sea, and the waters uninfluenced by shoals, currents, straits, or tempests. But in every part of the sea, near the shores, the geographer must come in to correct the calculations of the astronomer. For, by reason of the shallowness of some places and the narrowness of the straits in others, there arises a great diversity in the effect, not to be accounted for without an exact knowledge of all the circumstances of the place. In the great depths of the ocean, for instance, a very slow and imperceptible motion of the whole body of water will suffice to raise its surface several feet high; but if the same increase of water is to

be conveyed through a narrow channel, it must rush through it with the most impetuous rapidity. Thus, in the English Channel, and the German Ocean, the tide is found to flow strongest in those places that are narrowest; the same quantity of water being, in this case, driven through a smaller passage. It is often seen, therefore, pouring through a strait with great force; and by its rapidity considerably raised above the surface of that part of the ocean into which it runs.

This shallowness and narrowness in many parts of the sea also give rise to a peculiarity in the tides of some parts of the world. For in many places, and in our own seas in particular, the greatest swell of the tide is not while the moon is in its meridian height, and directly over the place, but some time after it has declined from thence. The sea, in this case, being obstructed, pursues the moon with what despatch it can, but does not arrive with all its waters till long after the moon has ceased to operate. Lastly, from this shallowness of the sea, and from its being obstructed by shoals and straits, we may account for the Mediterranean, the Baltic, and the Black Sea having no sensible tides. These, though to us they seem very extensive, are not, however, large enough to be affected by the influence of the moon; and as to their communication with the ocean through such narrow inlets, it is impossibe in a few hours time that they should receive and return water enough to raise or depress them in any considerable degree.

In general, therefore, we may observe, that all tides are much higher and more considerable in the torrid zone than in the rest of the ocean; the sea in those parts being generally deeper and less affected by change able winds or winding shores. The greatest tide we know of is that at the mouth of the river Indus, where the water rises thirty feet in height. How great, therefore, must have been the amazement of Alexander's soldiers at so strange an appearance! They who always before had been accustomed only to the scarcely perceptible risings of the Mediterranean, or the minute intumescence of the Black Sea, when made at once spectatators of a river rising and falling thirty feet in a few hours, must no doubt have felt the most extreme awe, with a mixture of curiosity and apprehension. The tides are also remarkably high on the coasts of Malay, in the straits of Sunday, in the Red Sea, at the mouth of the river St. Lawrence, along the coasts of China and Japan, at Panama, and in the gulf of Bengal. The tides at Tonquin, however, are the most remarkable in the world. In this part there is but one tide and one ebb in twenty-four hours; whereas, as we have said before, in other places there are two. Besides, twice in each month, when the moon is near the equinoctial, there is no tide at all-the water being for some time quite stagnant. These, with some other odd appearances attending the same phenomena, were considered by many as inscrutable; but Sir Isaac Newton, with peculiar sagacity, adjudged them to arise from the concurrence of two tides one from the South Sea, and the other from the Indian Ocean. Of each of these tides there come successively two every day-two at one time greater, and two at another that are less. The time between the arrival of the two greater is considered by him as high tide the time between the two lesser as ebb. In short, with this clue that great mathematician solved every appearance, and so established his theory as to silence

causes. This tendency of the sea towards the west is plainly perceivable in all the great straits of the oceanas, for instance, in those of Magellan, where the tide, running in from the east, rises twenty feet high, and continues flowing six hours; whereas the ebb continues but two hours, and the current is directed to the west. This proves that the flux is not equal to the reflux; and that from both results a motion of the sea westward, which is more powerful during the time of the flux than the reflux.

But this motion westward has been sensibly observed by navigators in their passage back from India to Madagascar, and so on to Africa. In the great Pacific Ocean, also, it is very perceivable; but the places where it is most obvious are, as was said, in those straits which join one ocean to another-in the straits between the Maldiva Islands, in the gulf of Mexico, between Cuba and Yucatan. In the straits of the gulf of Paria, the motion is so violent that it has received the appellation of the Dragon's Mouth. Northward, in the sea of Canda, in Waigat's Straits, in the straits of Java, and, in short, in every strait where the ocean on one part pours into the ocean on the other. In this manner, therefore, is the sea carried with an unceasing circulation round the globe; and, at the same time that its waters are pushed backward and forward with the tide, they have thus a progressive current to the west, which, though less observable, is not the less real.

Besides these two general motions of the sea, there are others which are particular to many parts of it, and are called "currents." These are found to run in all directions-east, west, north, and south-being formed, as was said above, by various causes; the prominence of the shores, the narrowness of the straits, the varia tions of the wind, and the inequalities at the bottom. These-though no great object to the philosopher, as their causes are generally local and obvious-are of the most material consequence to the mariner, and without a knowledge of which he could never succeed. It often has happened, that when a ship has unknowingly got into one of these everything seems to go forward with success; the mariners suppose themselves every hour approaching their wished-for port-the wind fills their sails and the ship's prow seems to divide the water; but at last, by miserable experience, they find that instead of going 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 the log-line, with a buoy made for that purpose, and by the direction and motion of this they judge of the setting and rapidity of the current.

These currents are generally found to be most violent under the equator, where indeed all the motions of the ocean are most perceivable. Along the coast of Guinea, if a ship happens to overshoot the mouth of any river it is bound to, the current prevents its return; so that it is obliged to steer out to sea, and take a very large com. pass, in order to correct the former mistake. These set in a contrary direction to the general motion of the sea westward-and that so strongly, that a passage which, with the current, is made in two days, is with difficulty performed in six weeks against it. However, they do not extend above twenty leagues from the coast; and ships going to the East Indies take care not to come within the sphere of their action. At Sumatra, the currents, which are extremely rapid, run from south to north: there are also strong currents between Madagascar and the Cape of Good Hope. On the western coasts of America the current always runs from the south to the north, where a south wind continually blowing most probably occasions this phenomenon. But the currents that are most remarkable are those

continually flowing in the Mediterranean Sea, both from the ocean by the straits of Gibraltar and its other extremity from the Euxine Sea by the Archipelago. This is one of the most extraordinary appearances in Nature, this large sea receiving not only the numerous rivers that fall into it-such as the Nile, the Rhone, and the Po-but also a very great influx from the Euxine Sea on one part and the ocean on the other. At the same time, it is seen to return none of the waters it is thus known to receive. Outlets running from it there are none; no rivers but such as bring it fresh supplies; no straits but what are constantly pouring their waters into it. It has therefore been the wonder of mankind in every age how and by what means this vast concourse of waters are disposed of; or how this sea, which is always receiving and never returning, is no way fuller than before. In order to account for this, some have said that the water was re-conveyed by subterraneous passages into the Red Sea. There is a story told of an Arabian califf 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 time after a dolphin was caught in the Red Sea, 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 endeavoured 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, and find that the quantity exhausted by evaporation greatly exceeds the quantity supplied by rivers and seas. This solution no doubt would be satisfactory did not the ocean and the Euxine evaporate as well as the Mediterranean; and as these are subject to the same drain, it must follow that all the seas will in this respect be upon a par; and therefore there must be some cause for this unperceived drain and continual supply. This seems to be satisfactorily accounted for by Dr. Smith, who supposes an under current running through the straits of Gibraltar to carry out as much water into the ocean as the upper current continually carries in from it. To confirm this, he observes that nearer home, between the north and the south foreland, the tide is known to run one way and the ebb another way at bottom. This double current he also confirms by an experiment communicated to him by an able seaman, who, being with one of the king's frigates in the Baltic, found he went with his boat into the mid-stream, and was carried violently by the current; upon which a basket was sunk, with a large cannon-ball, to a certain depth of water, which gave a check to the boat's motion; as the basket sunk still lower, the boat was driven, by the force of the water below, against the upper current; and the lower the basket was let down the stronger the under current was found, and the quicker was the boat's motion against the upper stream, which seemed not to be above four fathoms deep. From hence we may readily infer that the same cause may operate at the straits of Gibraltar; and that while the Mediterranean seems replenishing at top it may be empty at bottom.

The number of the currents at sea are impossible to be recounted, nor indeed are they always known; new ones are daily produced by a variety of causes, and as quickly disappear. When a regular current is opposed by another in a narrow 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-placing at the cen

tre of the whirlpool a dreadful den, fraught with monsters whose howlings served to add new horrors to the dashings of the deep. Mankind at present, however, view the 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 concus sion 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 Sylla 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 scarce 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 coast 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 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 come within the sphere of its violence-trees, 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 goes in a current opposite to his intentions; his vessel's motion, though slow in the beginning, becomes every moment more rapid; it grows 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.

F

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 scarce 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. Besides these agitations, the currents act their part in a smaller sphere, being generally greatest where the other motions of the sea are least-namely, nearest the shore; the winds also contribute their share in this universal fluctuation; so that scarce any part of the sea is wholly seen to stagnate. 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.

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, 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 Bordeaux, are composed of rocks; as are also those of Spain and England, which defend the land, and are only interrupted here and there to give an egress to rivers, and to grant the convenience of bays and harbours to our shipping. It may be in general 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 intunes cence, 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 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 less impediments having long before been surmounted and 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 admeasurement was found to be 600 fathoms perpendicular above the surface of the sea. Here 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 shores 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 corkjacket, will save him; the weight of the superincumbent waves break upon him at once, and crushes him with certain ruin. Some few of the natives, however, have the art of swimming and 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 generally seen to descend with a more gradual declivity. 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 the shelv ing shore wear the colour of the sky, and seem rising to meet it. The deafening noise of the sea is here converted into gentle murmurs; instead of the water 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, besides 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 distruction. 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 surperiority by slow and certain ap proaches, 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 continually bringing its sediment to one place, and by the accumula tion of its sands in another, is easily conceived. We have had many instances of the 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 hottom 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 burden. The like also may be seen at that bank called the " Dogger sands," where two tides meet, and which thus receive 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 scarce 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 Yucatan, 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 leagues 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 time 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 well assured, that in the memory of man the sea has gained fifty yards in some places, and lost as much in others.

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 of 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 now forms that bank called the Goodwin Sands. In the year 1546 a similar eruption of the sea destroyed a hundred thousand persons in the territory of Dordt, 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 main land, and still daily advances upon the continent. The German Sea has advanced upon the shores of Holland, near Catt; so that the ruins of an ancient citadel of the Romans, which was 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 it has lost or something 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. 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 time of Bede (about 1100 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 open 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 earth in like manner. It has continued for some ages to relinguish its former conquests; and although the inhabitants can neither boast the longevity nor the luxuries of their former pre-occupants, 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 doubt. I mean those numerous trees that are found buried at considerable depths in places where either rivers or the sea has 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 with 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 verdure, 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