along with their currents; and at last depositing them in some particular place. At the mouths of most great rivers, there are to be seen banks thus formed by the sand and mud carried down with the stream, which have rested at that place, where the force of the current is diminished by its junction with the sea. These banks by slow degrees increase at the bottom of the deep; the water in those places is at first found by mariners to grow more shallow; the bank soon heaves up above the surface; it is considered, for a while, as a tract of useless and barren sand; but the seeds of some of the more hardy vegetables are driven thither by the wind, take root, and, thus binding the sandy surface, the whole spot is clothed in time with a beautiful verdure. In this manner there are delightful and inhabited islands at the mouths of many rivers, particularly the Nile, the Po, the Mississippi, the Ganges, and the Senegal. There has been, in the memory of man, a beautiful and large island formed in this manner at the mouth of the river Nanquin, in China, made from depositions of mud at its opening it is not less than sixty miles long, and about twenty broad. La Loubere informs us, in his voyage to Siam, that these sand-banks increase every day at the mouths of all the great rivers in Asia; and hence, he asserts, that the navigation up these rivers becomes every day more difficult, and will, at one time or other, be totally obstructed. The same may be remarked with regard to the Wolga, which has at present 70 openings into the Caspain Sea; and of the Danube, which has seven into the Euxine. We have had an instance of the formation of a new island not very long since at the mouth of the Humber, in England. It began its appearance at low water, for the space of a few hours; and was buried again till the next tide's retreat. Thus, successively, it lived and died until the year 1666, when it began to maintain its ground against the insult of the waves, and first invited the aid of human industry. A bank was thrown about its rising grounds; and, being thus defended from the incursions of the sea, it became firm and solid, and, in a short time, afforded good pasturage for cattle. It is about nine miles in circumference, and is worth to the proprietor about eight hundred pounds a-year." It would be endless to mention all the islands that have been thus formed, and the advantages that have been derived from them. However, it is frequently found, that new islands may be often considered as only turning the rivers from their former beds; so that, in proportion as land is gained at one part, it is lost by the overflowing of some other.

66

Little, therefore, is gained by such accessions; nor is there much more by the new islands which are sometimes formed from the spoils of the continent. Mariners assure us that there are sometimes whole plains unrooted from the main lands by floods and tempests. These being carried out to sea, with all the trees and animals upon them, are frequently seen floating in the ocean, and exibiting a surprising appearance of rural tranquillity in the midst of danger. The greatest part, however, having the earth at their roots at length washed away, are dispersed, and their animals drowned; but now and then some are found to brave the fury of the ocean, till, being stuck either among rocks or sands, they again take firm footing, and become permanent islands.

As different causes have thus concurred to produce new islands, so we have accounts of others that the same causes have contributed to destroy. We have already seen the power of earthquakes exerted in sinking whole cities, and leaving lakes in their room. There have been islands, and regions also, that have shared the same fate, and have sunk with their inhabitants ever more to be heard of. Thus Pausanias tells us of an island, called Chryses, that was sunk near Lemnos. Pliny mentions several; among others, the island Cea, for thirty miles, having been washed away, with several

thousands of its inhabitants. But of all the noted devastations of this kind, the total submersion of the island of Atalantis, as mentioned by Plato, has been most the subject of speculation. Mankind in general now consider the whole of his description as an ingenious fable; but when fables are grown famous by time and authority, they become an agreeable, if not a necessary, part of literary information.

"About nine thousand years are passed," says Plato, "since the island of Atalantis was in being. The priests of Egypt were well acquainted with it; and the first heroes of Athens gained much glory in their wars with the inhabitants. This island was as large as Asia Minor and Syria united, and was situated beyond the Pillars of Hercules, in the Atlantic Ocean. The beauty of the buildings and the fertility of the soil were far beyond anything a modern imagination can conceive; gold and ivory were every where common; and fruits of the earth offered themselves without cultivation. The arts and courage of the inhabitants were not inferior to the happiness of their situation; and they were frequently known to make conquests, and overrun the continents of Europe and Asia." The imagination of the poetical philosopher riots in the description of the natural and acquired advantages which they long enjoyed in this charming region. If," says he, we compare that country to our own, ours will appear a mere wasted skeleton when opposed to it. The mountains to the very tops were clothed with fertility, and poured down rivers to enrich the plains below."

66

However, all these beauties and benefits were destroyed in one day by an earthquake sinking the earth, and the sea overwhelming it. At present, not the smallest vestige of such an island is to be found: Plato remains as the only authority for its existence; and philosophers dispute about its situation. It is not for me to enter into the controversy, when there appears but little probability to support the fact; and, indeed, it would be useless to run back nine thousand years in search of difficulties, as we are surrounded with objects that more closely affect us, and which demand admiration at our very doors. When I consider, as Lactantius suggests, the various vicissitudes of Nature-lands swallowed by yawning earthquakes, or overwhelmed in the deep; rivers and lakes disappearing, or dried away; mountains levelled into plains, and plains swelling up into mountainsI cannot help regarding this earth as a place of very little stability-as a transient abode of still more transitory beings.

Having at last, in some measure, emerged from the deeps of the earth, we come to a scene of greater splendour-the contemplation of its external appearance. In this survey, its mountains are the first objects that strike the imagination and excite our curiosity. There is not, perhaps, anything in all Nature that impresses an unaccustomed spectator with such ideas of awful solemnity as these immense piles of Nature's erecting, that seem to mock the minuteness of human magnificence.

In countries where there are nothing but plains, the smallest elevations are apt to excite wonder. In Holland, which is all a flat, they show a little ridge of hills near the sea-side, which Boerhaave generally marked out to his pupils as being mountains of no small consideration. What would be the sensations of such an auditory, could they at once be presented with a view of the heights and precipices of the Alps or the Andes! Even among us in England, we have no adequate idea

We in this part of the world are not, for that reason, so immediately in the question which has so long been agitated among philosophers, concerning what gave rise to these inequalities on the surface of the globe. In our own happy region we generally see no inequalities but such as contribute to use and beauty; and we therefore are amazed at a question inquiring how such necessary inequalities came to be formed, and seeming to express a wonder how the globe comes to be so beautiful as we find it. But though with us there may be no great cause for such a demand, yet in those places where mountains deform the face of Nature-where they pour down cataracts, or give fury to tempests-there seems to be good reason for inquiry either into their causes or their uses. It has therefore been asked by many in what manner mountains have come to be formed, or for what uses they are designed.

To satisfy curiosity in these respects much reasoning has been employed, and very little knowledge propagated. With regard to the first part of the demandthe manner in which mountains were formed-we have already seen the conjectures of different philosophers on that head-one supposing that they were formed from the earth's broken shell at the time of the deluge; another, that they existed from the creation, and acquired their deformities in process of time; a third, that they owed their origin to earthquakes; and still a fourth, with much more plausibility than the rest, ascribing them entirely to the fluctuations of the deep, which he supposes in the beginning to have covered the whole earth. Such as are pleased with disquisitions of this kind may consult Burnet, Whiston, Woodward, or Buffon. Nor would I be thought to decry any mental amusements, that at worst keep us innocently employed; but, for my own part, I cannot help wondering how the opposite demand has never come to be made, and why philosophers have never asked how we come to have plains. Plains are sometimes more prejudicial to man than mountains. Upon plains an inundation has a greater power; the beams of the sun are often collected there with suffocating fierceness; they are sometimes found desert for several hundred miles together, as in the country east of the Caspian Sea, although otherwise fruitful, merely because there are no risings nor depressions to form reservoirs, or collect the smallest rivulet of water. The most rational answer, therefore, why either mountains or plains were formed, seems to be that they were thus fashioned by the hand of Wisdom, in order that pain and pleasure should be so contiguous as that mortality might be exercised either in bearing the one or communicating the other.

Indeed, the more I consider this dispute respecting the formation of mountains, the more I am struck with the futility of the question. There is neither a straight line nor an exact superficies in all Nature. If we consider a circle, even with mathematical precision, we shall find it formed of a number of small right lines joining at angles together. These angles, therefore, may be considered in a circle as mountains are upon our globe; and to demand the reason for the one being mountainous or the other angular, is only to ask why a circle is a circle, or a globe is a globe. In short, if there be no surface without inequality in Nature, why should we be surprised that the earth has such? It has often been said that the inequalities of its surface are scarcely distinguishable, if compared with its magnitude; and I think we have every reason to be content with the

answer.

Some, however, have avoided the difficulty by urging the final cause. They allege that mountains have been formed merely because they are useful to man. This carries the inquirer but a part of the way; for no one can affirm that in all places they are useful. The contrary is known, by horrid experience, in those valleys that are subject to their influence. However, as the utility of any part of our earthly habitation is a very pleasing and flattering speculation to every philosopher, it is not to be wondered that much has been said to prove the usefulness of these. For this purpose, many conjectures have been made that have received a degree of assent even beyond their evidence; for men were un willing to become more miserably wise.

It has been alleged, as one principal advantage that we derive from them, that they serve, like hoops or ribs, to strengthen our earth, and to bind it together. In consequence of this theory, Kircher has given us a map of the earth, in this manner hooped with its mountains; which might have a more solid foundation, did it entirely correspond with truth.

Others have found a different use for them, especially when they run surrounding our globe; which is, that they stop the vapours which are continually travelling from the equator to the poles; for these being urged by the heat of the sun from the warm regions of the line, must all be accumulated at the poles if they were not stopped in their way by those high ridges of mountains which cross their direction. But an answer to this may be, that all the great mountains in America lie lengthwise, and therefore do not cross their direction.

But to leave these remote advantages, others assert that not only the animal but vegetable part of the creation would perish for want of convenient humidity, were it not for their friendly assistance. Their summits are, by these, supposed to arrest, as it were, the vapours which float in the regions of the air. Their large inflexions and channels are considered as so many basins prepared for the reception of those thick vapours and impetuous rains which descend into them. The huge caverns beneath are so many magazines or conservatories of water for the peculiar service of man; and those orifices by which the water is discharged upon the plain are so situated as to enrich and render them fruitful, instead of returning through subterraneous channels to the sea, after the performance of a tedious and fruitless circulation.

However this be, certain it is that almost all our great rivers find their source among mountains; and, in general, the more extensive the mountain the greater the river: thus the river Amazon, the greatest in the world, has its source among the Andes, which are the highest mountains on the globe; the river Niger travels a long course of several hundred miles from the Mountains of the Moon, the highest in all Africa; and the Danube and the Rhine proceed from the Alps, which are probably the highest mountains of Europe.

It need scarcely be said that, with respect to height, there are many sizes of mountains, from the gently rising upland to the tall, craggy precipice. The appearance is different in different magnitudes. The first are clothed with verdure to the very tops, and only seem to ascend to improve our prospects, or supply us with a purer air: but the lofty mountains of the other class have a very different aspect. At a distance their tops are seen, in wavy ridges, of the very colour of the clouds, and only to be distingushed from them by their figure, which, as I have said, resemble the billows of the sea. As we approach, the mountain assumes a deeper colour; it gathers upon the sky, and seems to hide half the horizon behind it. Its summits also are become more distinct, and appear with a broken and perpendicular line. What at first seemed a single hill is now found to be a chain of continued mountains, whose tops, running along in ridges, are embosomed in each other; so

that the curvatures of one are fitted to the prominences of the opposite side, and form a winding valley between, often of several miles in extent; and all the way continning nearly of the same breadth.

Nothing can be finer or more exact than Mr. Pope's description of a traveller straining up the Alps. Every mountain he comes to he thinks will be the last; he finds, however, an unexpected hill rise before him; and that being scaled, he finds the highest summit almost at as great a distance as before. Upon quitting the plain, he might have left a green and a fertile soil, and a climate warm and pleasing. As he ascends, the ground assumes a more russet colour; the grass becomes more mossy, and the weather more moderate. Still, as he ascends, the weather becomes more cold and the earth more barren. In this dreary passage he is often entertained with a little valley of surprising verdure, caused by the reflected heat of the sun collected into a narrow spot on the surrounding heights. But it much more frequently happens that he sees only frightful precipices beneath, and lakes of amazing depths from whence ivers are formed, and fountains derive their origin. On those places next the highest summits vegetation is scarcely carried on; here and there a few plants of the most hardy kind appear. The air is tolerably cold either continually refrigerated with frosts or disturbed with tempests. All the ground here wears an eternal covering of ice, and snows that seem constantly accumulating. Upon emerging from this war of the elements, he ascends into a purer and serener region, where vegetation is entirely ceased; where the precipices, composed entirely of rocks, rise perpendicular above him; while he views beneath him all the combat of the elements clouds at his feet, and thunders darting upward from their bosoms below. A thousand meteors, which are never seen on the plain, present themselves. Circular rainbows, mock suns, the shadow of the mountain projected upon the body of the air, and the traveller's own image, reflected as in a looking-glass, upon the opposite cloud.

Such are, in general, the wonders that present themselves to a traveller in his journey either over the Alps or the Andes. But we must not suppose that this picture exhibits either a constant or an invariable likeness of those stupendous heights. Indeed, nothing can be more capricious or irregular than the forms of many of them. The tops of some run in ridges for a consider able length without interruption; in others, the line seems indented by great valleys to an amazing depth. Sometimes a solitary and a single mountain rises from the bosom of the plain; and sometimes extensive plains, and even provinces, as those of Savoy and Quito, are found embosomed near the tops of mountains. In general, however, those countries that are most mountainous are the most barren and uninhabitable.

If we compare the heights of mountains with each other, we shall find that the greatest and highest are found under the line. It is thought by some that the rapidity of the earth's motion in these parts, together with the greatness of the tides there, may have thrown up those stupendous masses of earth. But, be the cause as it may, it is a remarkable fact, that the inequalities of the earth's surface are greatest there. Near the poles, the earth, indeed, is craggy and uneven enough; but the height of the mountains there is very inconsiderable. On the contrary, at the equator, where Nature seems to sport in the amazing size of all her productions, the plains are extensive, and the mountains remarkably lofty Some of them are known to rise three miles per pendicular above the bed of the ocean.

To enumerate the most remarkable of these, according to their size, we shall begin with the Andes, of which we have an excellent description by Ulloa, who went thither by command of the King of Spain, in company with the French Academicians, to measure a degree of

the meridian. His journey up these mountains is too curious not to give an extract from it.

After many incommodious days' sailing up the river Guayquil, he arrived at Caracol, a town situated at the foot of the Andes. Nothing could exceed the inconveniences which he experienced in this voyage, from the flies and mosquitoes (an animal resembling our gnat). "We were the whole day," says he, "in continual motion to keep them off; but at night our torments were excessive. Our gloves, indeed, were some defence to our hands, but our faces were entirely exposed; nor were our clothes a sufficient defence for the rest of our bodiesfor their stings, penetrating through the cloth, caused a very painful and fiery itching. One night, in coming to an anchor near a large handsome house that was uninhabited, we had no sooner seated ourselves in it than we were attacked on all sides by swarms of mosquitoes, so that it was impossible to have one moment's quiet. Those who had covered themselves with clothes, made for this purpose, found not the smallest defence; wherefore, hoping to find some relief in the open fields, they ventured out, though in danger of suffering in a more terrible manner from the serpents. But both places were equally obnoxious. On quitting this inhospitable retreat, we the next night took up our quarters in a house that was inhabited; the host of which, being informed of the terrible manner we had past the night before, he gravely told us that the house we so greatly complained of had been forsaken on account of its being the purgatory of a soul. But we had more reason to believe that it was quitted on account of its being the purgatory of the body. After having journied for upwards of three days through boggy roads, in which the mules at every step sunk up to their bellies,we began at length to perceive an alteration in the climate; and having been long accustomed to heat, we now began to feel it grow sensibly colder.

'If is remarkable, that at Tariguagua we often see instances of the effects of two opposite temperatures in two persons happening to meet-one of them leaving the plains below, and the other descending from the mountain. The former thinks the cold so severe, that he wraps himself up in all the garments he can secure; while the latter finds the heat so great, that he is scarce able to bear any clothes whatsoever. The one thinks the water so cold that he avoids being sprinkled by it; the other is so delighted with its warmth that he uses it as a bath. Nor is the case very different in the same person, who experiences the same diversity of sensation upon his journey up and upon his return. This difference only proceeds from the change naturally felt on leaving a climate to which one has been accustomed, and coming into another of an opposite temperature.

"The ruggedness of the road from Tariguagua leading up the mountain is not easily described. In some parts the declivity is so great, that the mules can scarce keep their footing; and in others, the acclivity is equally difficult. The trouble of having people going before to mend the road, the pains arising from the many falls and bruises, and the being constantly wet to the skin, might be supported, were not these inconveniences augmented by the sight of such frightful precipices and deep abysses as must fill the mind with ceaseless terror. There are some places where the road is so steep, and yet so narrow, that the mules are obliged to slide down, without making any use of their feet whatsoever. On one side of the rider, in this situation, rises an eminence of several hundred yards; and on the other, an abyss of equal depth; so that if he in the least checks his mule, so as to destroy the equilibrium, they both must unavoidably perish.

"After having travelled about nine days in this manner, slowly winding along the side of the mountain, we began to find the whole country covered with a hoar frost; and a hut in which we lay had ice on it. Hav