water of the flood, now contained in the bed of the Rhone, arrived in seventy minutes, the distance being about 50,000 feet; thus, the velocity of the river was necessarily from eleven to twelve feet per second. The flood being much diffused and divided in the plain of Martigny, the time occupied in crossing that district was of course longer than that occupied in its passage through the higher vallies.

Finally, from St Maurice to the Lake of Geneva, a distance approaching to 50,000 feet, the water and the rubbish took up about 230 minutes, which gives a velocity of about six feet per second. This velocity was, no doubt, much greater immediately below St Maurice, and much less near the Lake of Geneva; but the velocity of six feet per second expresses the medium velocity of the whole of this

passage.

We should deceive ourselves, were we only to estimate the advantage which resulted from the formation of the gallery through the new glacier, by the mass which passed through it in the course of three days; for not only did it draw off from the lake the 370 millions of cubic feet which issued by it, but it prevented the elevation of the level of the water to the height of the point of contact of the glacier with Mount Mauvoisin, a limit which, as we have seen, was sixty feet higher than the gallery; the lake would therefore have increased 15,000 feet in length, and its breadth would have exceeded 1000 feet. Again, sixty feet of additional surface height would have furnished a body of 900 millions of cubic feet of water; which, added to the 800 millions in the lake before the opening of the gallery, would have raised the entire volume of water in the lake to 1700 millions of cubic feet. Now, as the breaking up of the glacier only gave 530 millions of cubic feet of water, its mass was reduced to less than a third of the water which would have been accumulated in the lake, but for the judicious steps taken by the government of the Valais, by the advice and assistance of Mr Venetz.

There can be no doubt, that if these 1700 millions of cubic feet of water had accumulated in the lake, and had the latter begun to exceed the limit of contact between the glacier and Mount

Mauvoisin, the cascade which would have been thus formed, and which would have tumbled at once upon the loose earth which covered the rocky strata of Mount Mauvoisin, would have immediately decomposed and carried off this loose mass of rubbish and vegetable mould, and the lake would thus have forced a passage equally abrupt with that which took place. But a threefold mass of water suddenly escaping from this great reservoir, would certainly not have left the vestige of a habitation either in the valley of Bagne or St Branchier, and most probably all Martigny would have been utterly destroyed. There is still another circumstance to be considered, in order completely to appreciate the extent of the advantage which resulted from that gallery which was so cleverly executed. We have seen that the lake rose daily, during its execution, nearly two feet. After arriving at a height where its surface would have been increased in a greater proportion, this rising would no doubt have diminished in spite of the extraordinary melting of the snow and the ice, occasioned by the greatest heat. But, granting that the lake would have continued to rise at the same rate, the moment of the breaking up would have been delayed at least a month, and would thus have happened at the time the waters of the Rhone are highest. The 530 millions of cubic feet of water which it furnished to the river, were run off without causing damage on the 16th June, a period when the water of the river was still pretty low. But if these 1730 millions of cubic feet had been thrown into the bed of the Rhone when full, assuredly the whole of the bottom of the broad valley of the Rhone, from Martigny to the Lake of Geneva, would have shared, more or less, the disastrous fate of the valley of Bagne.

The new glacier of Mauvoisin, however, still exists in the channel of the Dranse. The mass which has been carried off by the effect of the gallery, and the bursting of the ice, forms but a very small portion of it; the channel by which the lake escaped is even shut up by the blocks of ice which have fallen from the upper glacier, and by masses which are occasionally detached from the edges of the new one. This accumulation of ice-blocks in the

mouth of the lake is even already so compact, that the Dranse can hardly work its way below the glacier; and a new lake, which, on the 24th of July, was a full quarter of a league in length, though as yet not very deep, announces, that the causes of a new flood still exist in this unfortunate district of the valley. If the internal heat of the earth succeed in melting the principal supports upon which rests the enormous cone of ice which has shut up the valley, it will sink a little, and will one day or other close up the narrow outlet which the river still finds beneath it. The heat of the atmosphere has even little influence on the surface of the glacier; threads of water, hardly visible, trickle down its sides; and, at four o'clock in the afternoon, the greatest part of the glacier is already in shadow under the high and precipitous side of the Pierre à Vire, a peak which overtops Mauvoisin. The nights are grow ing longer; one month more, and the new snow will cover the glacier; every return of a fine day will melt the snow on the sides of the neighbouring mountains, or produce avalanches which will augment the glacier, rendered more homogeneous by the cold water which filters through it and freezes. The winter, and even the approach of the spring, will multiply the causes of the increase of the glacier, which bars the valley, and which threatens, in the most alarming manner, the repetition in the course of next year of that scene of horror of which we have now been reading the details. The contents of the enormous mass of ice which forms the barrier has been calculated; it would appear to consist of more than fifty millions of cubic feet. We may contrast with it the powers of all the agents which physics and chemistry furnish to man, and which he so often abuses for the destruction of his species; but all these are as nothing against this gigantic mass, the approach even to which is dangerous, on account of the detached pieces of ice and rock which are continually falling from the upper glacier. If the most extensive mines were driven into it, the force of the powder would either be lost in the crevices which traverse the glacier, or cause new ones; or if, in more favourable circumstances, large blocks were blown up, they would fall upon the

glacier, or, rolling perhaps down its side to its base, they would only serve to increase its circumference; and one avalanche would increase, and probably double the mass which had been removed with so much expense and danger.

For

There is only one means by which this valley may be for ever put beyond the reach of similar, or even those still greater disasters which threaten the valley of the Rhone, as far as the lake of Geneva. This consists in opening a gallery in the calcareous strata of the foot of Mount Mauvoisin, or Pierre à Vire, which is immediately opposite to the fatal glacier. This subterraneous gallery ought to be made so long, that its entrance and outlet should be removed from the base of the glacier to such a distance as to prevent all risk of either the one or the other opening being choked up, and thus rendered useless. It would be necessary to make the gallery of a size sufficient to allow the whole of the Dranse to pass even at the period of the highest floods. this, it appears a gallery, ten feet high by eight feet broad, would be sufficient; for if the water run through it with a velocity of eight feet per second, as will be the case by giving the gallery the greatest possible inclination, a mass of water of 640 cubic feet may pass through in a second, which gives fifty-five millions of cubic feet in a day; and this volume exceeds the estimate which has been made from observations, of the quantity of water which the bottom of the valley could furnish even during the greatest melting of the snow. By means of such a gallery, the length of which might be 2000 feet, we should for ever give the Dranse a free issue by the bottom of the valley; and this outlet would be then altogether independent of the state of the glacier. We could even easily prolong this subterraneous outlet, in the improbable case of the increase of the glacier rendering it necessary to change the entrance or the outlet of the gallery.

All Switzerland is hastening to alleviate, by fraternal aid, the misfortunes of the inhabitants of the valley of the Dranse; a great number of foreigners, among whom the English are distinguished, having contributed to the same end. But what avails it to rebuild houses in ruins, if the same

catastrophe is impending over them? While, if the greater part of the money contributed by benevolence were employed on the execution of this gallery, the whole valley would be for ever safe; an advantage, without which every other will remain precarious.

There is still, in the present state of the valley of Bagne, a very disagree able circumstance, which cannot be amended but by the united labours of the inhabitants, or by the intervention of government. The enormous heaps of rocks and pebbles which the flood has formed in the valley, obstruct almost every where the course of the Dranse, and throw it upon the steep declivities which bound it. Here, as in every spot where a vigorous vegetation, either natural or the effect of agriculture, is produced on the slope of the mountains, these declivities are composed of debris from the upper rocks, which cover the base, originally naked and uncultivated: this again is covered with a layer of vegetable mould, generally pretty thin, which renders it fertile. But already the base of these slopes, more or less productive, and covered with forests, has been attacked in many quarters, and undermined at the base by the destructive effect of the flood; and thus the upper parts of these steep declivities are without support, and begin to slide into the bottom of the valley. Broad and deep crevices, which are sometimes a thousand feet in length from the bottom of the valley upwards, indicate this sliding down, whose consequences are so much to be deprecated. The melting of the snows next spring will fill these rifted slopes with a great quantity of water, which will soften, and cause them to shrink and tumble down, as generally happens in those which so often lay waste the different vallies of the Alps. The evil is not limited to the destruction of the vegetation of these declivities, but the torrent of the valley is filled with an enormous quantity of pebbles, which it rolls along as long as its slope gives it impulse it is in the plains or considerable vallies that these rolled pebbles are deposited, elevating the bed of the torrent, causing the banks to give way, and producing these inundations which so often desolate our low vallies.

If the Dranse be permitted to follow the disorderly course which it has received from the flood, it will undermine more and more the sides of the mountains of the valley of Bagne; its water, increased by the melting of the snows next spring, will unite with that which has insinuated itself into the numerous crevices, and produce more extensive destruction; the Dranse will be filled with these, and its course will thereby be rendered more irregular and destructive even to the Rhone, the bed of which is at present rising in a very sensible degree, and threatens injury to the lower parts of the valley. If every proprietor in the valley of Bagne is allowed to erect his dykes at pleasure on the bank, the evil will only be so much the greater, for these partial operations will unite with the irregularities of the natural course of the river to render it still more destructive. If it is meant to protect the interests of the valley, and to turn to the best account the small means left to the unfortunate inhabitants, they must not be permitted to waste their resources on partial operations on the torrent. Let as regular a course as possible be marked out for it in the middle of the valley; the perfect safety of all the population will then be insured, with the least possible expense; the torrent will be removed from the foot of the mountain sides, by giving it the straightest possible direction; the largest of the great rocks and pebbles, which cover the extensive plains, will be accumulated as much as possible at the foot of the slopes already attacked; and while dangerous and sudden overflowing will be prevented, the bottom of the valley will be cleared of the greatest obstacles to its renewed cultivation. The union of all human energy, wisely directed, is required to diminish the evils which extraordinary accidents very often occasion in the Alps. Individual exertion can do little against such misfortunes, and partial charity but too often diverts the unfortunate object of it from the means which would effectually ameliorate his condition. The population of a whole district is very often insufficient to repair the ravages of the elements in our Alps. A greater union of strength and means is required to remedy great misfortunes, and to guard against their return. A whole valley, nay, a whole canton, ought sometimes to unite to obtain this end. But after

certain disasters, a union of means still greater than any one canton can furnish, is requisite to save the population of an entire district. In such cases, the whole nation ought to unite around the altar of their native country, and of humanity. Let us not overlook, in this dispensation, in this urgent and affecting case, in which man receives assistance from his neighbour, his fellow-citizen, and his country, the plan of Providence for uniting man with man, the village with its neighbour, the valley with a whole country, and every part of the nation with the whole nation. The free man respects those sacred bonds which give unity to every nation, and assures it civilization, duration, and happiness. ESCHER DE LA LINTH. Berne, August, 1818.

ACCOUNT OF THE EXPEDITION TO

THE NORTH pole.

[THE following account of the expedition to the North Pole, to the result of which all Europe is looking with anxiety, has been drawn up from original letters from Captain Ross and Lieut. Robertson of the Isabella,

and from other documents; and we con

sider ourselves particularly fortunate in having had it in our power to present our readers with so full and interesting an abstract of its proceedings.]

THE ships under Captain Ross's command left Shetland on the 3d May, and, after a good passage across the Atlantic, they reached Cape Farewell on the 22d. The variation now increased as they advanced to the west, and the thermometer stood at 421. In latitude 58° 38', and west longitude 50° 54', the first iceberg was seen with much loose ice floating around.

On the 2d of June the main west ice appeared, in latitude 65° and longitude 56°. On the 4th they made the coast of Greenland, in latitude 65° 62. The variation this day was as follows:

Variation.

Ship's head N. to compass, 66° 22′ W. Ship's head S., 58° 23′ W. Ship's head E.S.E., 47° 23′ W. Ship's head W., 77° 34′ W. On the 8th of June the Isabella was hemmed in with ice on all sides; and though a south-west gale was blowing, she was obliged to tack about where she could find room.

On the 9th of June they anchored to an iceberg, which was aground about a mile from the shore, in 38 fathoms of water, in latitude 68° 22′, and longitude 53° 42', and they now obtained an accurate measure of the variation, free from any irregularity in the action of the ship. The variation was found to be 67° 39′ W., and the dip 83° 7'. This iceberg was so firmly moored, that the levels of the dipping-needle were not in the slightest degree affected. In anchoring to an iceberg, the boat goes ahead with the anchors, and fixes them before the ship approaches. The ship then stands in, and makes fast her bow to the ice. An iceberg that is aground is always preferred; and if it is so low that the bowsprit can lie over it, so much the better.

On the 16th, they touched at the Whale Islands, where there is a Danish resident, who told them that the preceding winter had been a very se

vere one.

On the 15th, the Isabella anchored to an iceberg about a mile from the north-west coast of Waygatt, or Hare Island. All the astronomical apparatus was now got ashore, a temporary observatory was erected, and the following accurate observations on the variation and dip were obtained : North lat. of observatory, 70° 26′ 13′′ West long. of ditto, Variation west,

Dip,

54° 51′ 49′′ 71° 30'

82° 48' 47" A pendulum, which vibrated 82 seconds more than twenty-four hours in the latitude of London, when the temperature was 52°, vibrated in Waygatt Island 153 seconds more than twentyfour hours, when the temperature was 43°. Waygatt, or Hare Island, is about nine miles long, and 1400 feet high. Some of the rocks are basaltic, and coal is found near the surface, in the north-east part of it. The latitude of the island is 70° 22′ 15′′ W., and its longitude 54° 51' W., instead of 50° 15', as given in the charts.

On the 20th of June the ice opened a little to the northward, and the Isabella and the Alexander attempted to get to the coast of Greenland, by warping and towing the ships through the straits. The winds were light and variable, with frequent calms. The Isabella was first in the attempt, and was drifted about with the ice, by the tides, till the morning of Monday the

22d. The Alexander, however, was more fortunate, and succeeded in getting over to the land, and into clear water, on the evening of Sunday the 21st, when it anchored to an iceberg to wait for the Isabella.

On the 26th of June, at the distance of only twenty miles from Waygatt Island, the Isabella got into a piece of clear water that carried them to the land-ice, on the north side of Jacob's Bight, where they made the following observations. North latitude, West longitude. Variation on the ice,

71° 21'

54° 17'

75° 29'

The ship was now swung, and azimuths taken on board at every five points, when the following results were obtained.

Variation.

Ship's head, NORTH, 77° 43′ W. Ship's head, NORTH EAST, 70° 30′ W. Ship's head, EAST, 64° 56′ W. Ship's head, SOUTH EAST, 67° 7' W. Ship's head, SOUTH, 76° 27′ W. Ship's head, SOUTH WEST, 84° 38′ W. Ship's head, WEST, 93° 33′ W. Ship's head, NORTH WEST, 90° 20′ W. Captain Ross is decidedly of opinion, though there is some difference of sentiment on the subject, that the following points are established by his observations: 1. That the deviation occasioned by the direction of the ship head, is not on the magnetic meridian, but differs in every ship. In the Isabella, it is to the east of north, and in the Alexander, and the Harmony of Hull, to the westward of north. 2. That there is a point of change in the deviation, which may easily be found by azimuth or bearings of a distant object; and that when this point of deviation is found, it may in like manner be found what proportion is to be added or subtracted from the true variation, but only by actual observation, for the deviation does not increase either in an arithmetical or logarithmic proportion. On board the Isabella, and in latitude 74°, the point of change is N. 17° E. The extreme deviation is, when the ship's head is N. 80° W. viz. 19°, which is additive to the true variation; so that with the ship's head W. and N. there is 100° of variation; or by steering W. and N. the ship actually makes a S. by E. course. On the other hand, the variation decreases when the ship's head is to the east, but not in an equal ratio,

the extreme being 17°, making the variation 64° on that tack.

On the 27th June, when there was the appearance of an opening, the Isabella cast off from the ice, and cruised about in a narrow pool for several days.

On the 2d of July a fine fresh breeze opened a passage for the ships, and on the 3d they were in latitude 71° 30', and on the 4th in latitude 72° 30'. The following measure of the variation was then taken :

North latitude,

72° 44' Variation on the ice, 78° 54' W.

On the 5th of July they were in 73° 15′ north latitude, and 57° 14' west longitude. Some of the Esquimaux families visited both the Isabella and the Alexander. The women are dressed in the same manner as the men, only their hair is tied on the crown of their head, and they have a small sort of peak on the fore and after part of their jackets. These families reported, that the part of the sea where they were had been clear of ice the whole winter; that no whales had been seen during the season; and that, in their opinion, there would be plenty of clear water to the northward. This opinion was considered probable; for though the number of icebergs were, in the present latitude, as at Riskoll, Waygatt Island, and Black Hook, almost beyond belief, yet the field ice appeared by no means so close as to stop their progress. One of these icebergs, which was measur ed, was 123 feet above water, and aground in 125 fathoms, yet this was a very small one compared with some hundreds that had been seen. Whenever the depth of water is under 100 fathoms, there are found immense mountains of ice aground. In fine weather, streams of perfectly fresh water are continually flowing from them. Whenever a fog, with a north wind, touches these icebergs, it becomes ice, and adds to their bulk. The air, during these fogs, is 28°, and the water 314; but in clear weather the temperature has risen so high as 84° on an iceberg in the sun.

"From the 65th deg. to this, says Mr Robertson, the sea is literally covered with bergs, and we see no end to them: Where it is not in 74. or to the southward on this they are generated is yet unknown to us; coast. That they are formed on the land is certain, from the many stones of great size which are seen;-some of them are