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the water opened a passage for itself by breaking the glacier, its level had sunk forty-five feet below the greatest height which it had ever reached.

This diminution of the lake having taken place at the top, that is, at the point where it had the greatest breadth, it follows, estimating the breadth at only six hundred feet, that the gallery had effected a diminution of the water of the lake of two hundred and seventy millions of cubic feet at least: so that, at the moment of the breaking up, it did not contain more than five hundred and thirty millions of cubic feet of water, in place of the eight hundred millions which it contained three days before.

At the moment when the gallery began to produce the desired effect, the water which ran through it, rushed out of the outlet in a cascade, into the old bed of the Dranse, below the glacier, quickly melted the ice, and eat away the floor of the gallery at its mouth. The water which had insinuated itself into the rents and crevices, which penetrated the glacier in some places, especially at the edges, caused enormous masses of ice to fall with a crash from the lower sides of it. By these various united causes the gallery lost considerably in length; and the cascade hollowing out a very deep furrow, the mass of the glacier, which at this point formed the retaining wall of the lake, diminished so much in thickness, that the floor of the gallery, which at the outset was six hundred feet in length, was reduced to eight feet at the moment the whole lake forced the passage.

It was not, however, the giving way of this wall of ice, now become so slight, which was the immediate cause of the frightful deluge-that was caused by another accident. After the cascade had formed a channel some hundred feet deep, in the lower mass of the glacier, and, after penetrating more and more, had at last fallen upon the base of Mount Mauvoisin, which passed under the glaeier, and against which the latter rested-the base of the mountain not being at that point composed of rocks, but of a thick mass of debris covered with vegetable mould; the cascade, I say, attacked this loose mass and carried it off by degrees; and thus the water filtering into the earth, which it liquified, and which

was continually growing weaker, found itself at last sufficiently strong to push forward this soft soil from the foot of Mount Mauvoisin, and to wear itself a passage between the glacier and the layers of the rocks which composed the mountain. Immediately the lake rushed out all at once; the ice, which still remained between the gallery and Mount Mauvoisin, gave way with a horrible crash; and the body of the water forced its way out with such impetuosity, by the great opening which it had thus forced between the glacier and Mount Mauvoisin, that in half an hour the lake was completely emptied, and the five hundred and thirty millions of cubic feet of water which it contained, thundering down into the valley with a rapidity and violence of which no idea can be formed, destroyed every thing in their course. It is probable, that the rushing out of the lake would have been still more rapid, had it not been for the existence of a narrow gorgé immediately below the glacier, between Mount Pleuseur and an advanced point of Mount Mauvoisin. The water rushed into this gorge with such force, that it swept away the bridge of Mauvoisin, situated 90 feet above the level of the Dranse, and rose many toises above the projecting mass of Mount Mauvoisin. After leaving this narrow channel, the enormous mass of water spread itself over a broader part of the Val de Bagne, which forms a pretty large bason, contracted at the bottom by another gorge of the valley, through which it again escaped with such violence, that it carried off every thing which covered the rocks, even detached some of these, and hurled them into the abyss. A new bason in the valley then received this tremendous liquid mass, which swept on every side the foot of the mountains, carrying thence forests, detached rocks, houses, barns, cultivated land, and laying waste even the base of those steep, but more or less cultivated, sides of the two chains of mountains bounding this unfortunate valley. Many contractions, farther down the valley, raised the water to a considerable height, and increased the fury with which it inundated the lower plains, where every obstacle was overthrown and swept away. Enormous heaps of pebbles and rocks, which the floods had carried off higher up, were deposited in the plains,

which, but a moment before so beautiful and so populous, were now converted in a moment into a dreary desert. On reaching Chable, one of the principal villages of the valley, the water was confined between the piers of a strong bridge; the body of the flood, which appeared to contain even more debris than water, rose more than fifty feet above the ordinary level of the Dranse, and began to encroach on the inclined plain, upon which the church and the greater part of the village are built. A few feet more, and the water would have reached the village and destroyed it. At that important moment the bridge gave way, the houses at its two extremities were swept away; and the passage being now clear, the frightful mass of water and rubbish spread itself over the wide part of the valley, as far as St Branchier; every thing in its course was undermined, destroyed, and carried off. Houses, highways, fields covered with the finest crops, noble trees loaded with fruit, every thing was swallowed up and devoured. The moving chaos, charged with all thesespoils, now throws itself into the narrow valley of St Branchier à Martigny, through which lies the road of St Bernard ; as yet nothing resists the merciless torrent; all the parapets built along the edge of the Dranse are precipitated into the flood, which, reaching Martigny, and escaping from the narrow valley, diffuses itself over the plain, forming the great valley of the Rhone; covers the fields and orchards; runs through the town of Martigny; carries off from thence houses and barns; covers the whole plain with thick mud; thousands of trees torn up by the roots; wrecks of houses and furniture; dead bodies of men and animals; and, branching out, at last it precipitates itself into the bed of the Rhone. That river being at the time little affected by the water of the mountain snow, which had not yet begun to melt, received, without farther injury, all that remained moveable of that terrible flood, which had just laid waste one of the finest vallies of the Alps, to the extent of ten leagues in length.

According to the unanimous testimony of the inhabitants, the flood took up half an hour in passing every point which it reached; thus, in the short space of thirty minutes, the whole mass

of the water of the lake, drawing with it all the debris, and forming a column of more than 530 millions of cubic feet, passed every part of the valley. The flood then furnished in every second 300,000 cubic feet of water. The Rhine, below Basle, where all its waters, from the Tyrol to the Jura, are united, gives, during the season when its waters are highest, about 60,000 cubic feet of water per second. The flood of the unfortunate valley of Bagne, then, must have contained five times more water than the Rhine bears when at its height. This comparison may aid us to form some idea of the prodigious mass of water which produced such dreadful effects.

Agreeably to the information I collected, the flood took up thiry-five minutes in coming from the glacier to Chable. The distance between these two points, following the bed of the Dranse, is about 70,000 feet. The water, then encumbered with all the rubbish, moved with the velocity of thirty-three feet in a second. The velocity of the most rapid rivers is from six to ten feet per second; very few attain to the velocity of thirteen; thus, in the rectilineal and perfectly regular canal of Mollis, the Linth, after this canal is full, flows with a velocity of twelve feet per second. That of the torrent of the Val de Bagne, multiplied by the half solid mass which was in motion, explains extremely well the force with which forests, houses, and rocks, have been swept off and carried to a distance,

In passing from Chable to Martigny, the flood must have occupied about fifty-five minutes. The distance between those two places, following the windings of the valley, may be about 60,000 feet; the medium velocity of the current then, in this extent, was about eighteen feet per second. The inclination of that part of the valley being less than the upper portion of it, and the water having lost a part of the impulse resulting from its fall by the open gorge in the glacier, we may suppose that the velocity of the current was considerably diminished in this valley, which was lower and of a more uniform breadth; the time which the flood took up in passing through it, therefore, was in all probability longer than that occupied in traversing the upper valley.

From Martigny to St Maurice, the

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 80,000 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

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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 growing 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.

This

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. 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. For 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

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There is still, in the present state of the valley of Bagne, a very disagreeable 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 moun tain 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 ob stacles 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 popula tion 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

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