descent the views of the Rhone valley are characterised by peculiar grandeur. Martigny lies stretched out below; and the silvery Rhone appears winding amidst an amphitheatre of mountains, with an empurpled back-ground of higher Alps, crested with the purest snows. Among these is the Gemmi, hovering proudly above the road, now looking like a whitish line drawn along the valley; while the whole scene possesses a vast and solitary magnificence. A strange effect is produced on the frame, when, after the excessive heat of the sun-exposed ascent of about three hours, a cold blast from the glaciers of Savoy sends through it a wintry chill.

At a wretched hovel of a Douane the passports are demanded, and a fee of half a frane charged for the visé, which one might fain hope would be employed to diminish its miseries. Sardinia is now left behind; and very soon the flat, marshy end of the valley of the Rhone appears shut in on one side by the Bernese Alps, and on the other by the Mont Blanc range. The village and bourg of Martigny, appearing at the end of the valley, seem to be within a distance of two miles, and the hope arises that another half hour will complete the journey thither.

But disappointment ensues; the road downwards is exceedingly steep; and the ladies who accompanied us were obliged to dismount from their mules, and to avail themselves of the arms and alpenstocks of the rougher sex. As we were resting when half way down, and enjoying the refreshment of some sweet mountain cherries, we saw an eagle souring near the summit of one of the neighbouring clevations. The royal bird could not be distinctly perceived, but, remote as it was, its appearance and movements were truly majestic. Two hours after our disappointed hope, we espied the old tower of Martigny, just beyond the village, and a pedestrian trip of twenty-five miles rendered what we found in the salle-a-manger of the Hotel du Cygne singularly welcome.

Martigny, though in its appearance as a village not at all prepossessing, is pleasantly situated at the base of the mountains which form part of the great Mont Blanc range, in the widest part of the valley of the Rhone. Almost every traveller in this part of Switzerland visits it, yet scarcely any one leaves it with a feeling of regret. The scenery is fine, the hotels are not bad; but, then, the summer heat is scarcely tolerable, while the swarms of flies and troops of mosquitoes, in the latter part of the season, are excessively annoying. Happily, the latter had not arrived at the time of our visit; but the flies were the tormentors of our meals, and of the time designed for slumber. Sleep-even a doze-was out of the question; and, rising from our comfortless beds, we were off as early as possible, panting for some elevated spot, and athirst for some pure and cool mountain air.

We could not fail, however, to recall, while here, the occurrence of what is called in Alpine districts a debacle; it is, in fact, a flood of water arising from circumstances to which they are peculiarly expose:l. For if there be a narrow gorge between two mountains, and descending to a valley, a glacier frequently occupies it, and gradually descends till it entirely crosses the valley. If, then, there be a river flowing through the valley, this glacier may form a dam, when the river will rise behind it, and form a lake. So it was, on a memorable occasion, about forty years ago.

The Val de Bagnes, near Martigny, is a steep, narrow, rugged valley, running for about thirty or forty miles, in an east and west direction, among the mountains which separate Switzerland from Piedmont. The mountains have numerous glaciers in their gorges, or upper valleys, and, at one spot, a glacier protruded into the valley beneath. This valley has flowing along its bottom the river Dranse, a tributary to the Rhone, the banks of which are, in most places, precipitous, but presenting, here and there, some little spot capable of culture. Here, then, some hardy and industrious Swiss determine to dwell: each one builds a picturesque cottage; and, to connect these several rustic patches. together, the mountaineers throw rude and slender bridges across the glen, beneath

which the river flows; and thus, while culture adorns by fertility the otherwise rugged scene, there is an approach to the enjoyments of the social state.

Not far from the upper end of this valley is the spot where the glacier intruded on the channel where the river flows: blocks of ice and masses of snow derived from it having been precipitated, from time to time, so that the stream has been for ages more or less impeded. So long back, indeed, as the year 1595, the valley was completely shut up by the descent of enormous masses of ice; behind this barrier the water rose to an immense height; and at length, the barrier, weakened by the pressure of the water and the heat of the sun, gave way. At once, therefore, the accumulated waters rushed along the valley, carrying with them masses of rock of enormous magnitude, and, with irresistible fury, tore up everything that obstructed their progress, desolated the plains and valleys, and destroyed the whole town of Martigny. Sad was the wreck of property at this crisis, and lamentable the loss of human life!

Subsequently to this catastrophe, the ice and snow continued to fall into the valley at this spot from the glacier above; and as the mass was, at length, able to resist the heat of the summer's sun, a further accumulation was the consequence. The glacier, too, pursued its course downwards, so that, by the year 1818, the bed of the stream was blocked up by a conical mass of ice and snow, more than 100 feet in height. The river continued, for some time, to find its way either under or through the crevices in this barrier; but at last, fresh portions of mingled ice-rocks and snow were cast down from the sides of the glacier, and the various channels which the river had excavated became choked up. Immediately, therefore, as the waters had no outlet, they began to form a lake, which gradually increased till it became half a league in length, about 700 feet broad at the top, 100 feet at the bottom, having an average depth of 200 feet, and estimated to contain no less than 800,000,000 cubic feet of water.

In April, 1818, the Swiss saw the danger that impended from a barrier, not of rock, which might have resisted the pressure of the water and allowed it merely to form a cascade, but one constituted only of ice and snow. They felt, too, that unless prompt and energetic measures were taken, the barrier would give way, and the waters would at once dash down the ravine, destroy the villages, bridges, and mills, which, though built on spots sufficiently elevated to be secure from ordinary floods, would inevitably be swept away by such an inundation.

M. Venetz, an able engineer of Martigny, now devised a plan for lessening, if it could not avert, the evil. He concluded that the water might be prevented from rising above a certain level in the lake, could a tunnel be cut through the barrier of ice at such a height above the level of the lake at that time, as to allow of the work being finished before the water should rise to that point;-a task obviously requiring a very nice calculation, and no ordinary energy, for its completion. M. Venetz proposed, also, that the tunnel to be bored through the barrier should slope downwards, so that, when the water rose to its upper end, it should flow so rapidly through, that it might act like a saw, and, by cutting down the ice, permit the water from the lake gradually to descend, till it was nearly emptied, and the mass of water be prevented from becoming an overmatch for the retaining wall of ice and snow.

On the 10th of May, the task was begun by gangs of fifty men, who relieved cach other, and worked without intermission day and night, with inconceivable courage and perseverance, neither deterred by the daily occurring danger from the falling of fresh masses of the glacier, nor by the rapid increase of the water in the lake, which rose sixty-two feet in thirty-four days-on an average, nearly two feet each day; but it once rose five feet in one day, and threatened each moment to burst the dyke by its increasing pressure, or, rising in a more rapid proportion than the men could proceed with their work, render their efforts abortive, by rising above them. Sometimes dreadful noises

were heard, as the pressure of the water detached masses of ice from the bottom, which, floating, presented so much of their bulk above the water as led to the belief that some of them were seventy feet thick. The men persevered with their fearful duty without any serious accident, and though suffering severely from cold and wet, and surrounded by dangers which cannot be justly described, by the 4th of June they had accomplished an opening 600 feet long; but having begun their work at both sides of the dyke at the same time, the place where they ought to have met was twenty feet lower on one side of the lake than on the other;-it was fortunate that latterly the increase of the perpendicular height of the water was less, owing to the extension of its surface. They proceeded to level the highest side of the tunnel, and completed it just before the water reached them. On the evening of the 13th, the water began to flow. At first, the opening was not large enough to carry off the supplies of water which the lake received, and it rose two feet above the tunnel; but this soon enlarged from the action of the water, as it melted the floor of the gallery, and the torrent rushed through. In thirty-two hours the lake sank ten feet, and during the following twenty-four hours twenty feet more; in a few days it would have been emptied, for the floor melting, and being driven off as the water escaped, kept itself below the level of the water within; but the cataract which issued from the gallery melted and broke up also a large portion of the base of the dyke which had served as its buttress; its resistance decreased faster than the pressure of the lake lessened, and at four o'clock in the afternoon of the 6th of June, the dyke burst, and in half an hour the water escaped through the breach, and left the lake empty.

The greatest accumulation of water had been 800,000,000 of cubic feet; the tunnel, before the disruption, had carried off nearly 330,000,000. In half an hour, 530,000,000 cubic feet of water passed through the breach, or 300,000 feet per second; which is five times greater in quantity than the Rhine at Basle, where it is 1,300 feet wide. In one hour and a half, the water reached Martigny, a distance of eight leagues. Through the first 70,000 feet, it passed with the velocity of thirty-three feet per second-four or five times faster than the most rapid river known; yet it was charged with ice, rocks, earth, trees, horses, cattle, and men: thirty-four persons were lost, 400 cottages swept away, and the damage done in the two hours of its devastating power exceeded 1,000,000 of Swiss livres. All the people in the valley had been cautioned against the danger of a sudden irruption, yet it was fatal to so many. Every bridge in its course was swept away, and among them the bridge of Mauvoison, which was elevated ninety feet above the ordinary height of the Dranse.

If the dike had remained untouched, and it could have endured the pressure until the lake had reached the level of its top, a volume of 1,700,000,000 cubic feet of water would have been accumulated there, and a devastation much more extensive must have been the consequence. From this greater danger the people of the valley of the Dranse were preserved by the heroism and devotion of the brave men who effected the formation of the gallery, under the direction of M. Venetz. "I know no instance of courage," says Mr. Brockedon, "equal to this: their, risk of life was not for fame or riches; they had not the usual excitements to personal risk, in a world's applause or gazetted promotion; their devoted courage was to save the lives and property of their fellow-men, not to destroy them. They steadily and heroically persevered in their labours, amidst dangers such as a field of battle never presented, and from which some of the bravest brutes that ever lived would have shrunk in dismay. These truly brave Valaisans deserve all

honour!"

A remarkable incident may be connected with the circumstances now narrated. An English gentleman, and a young artist, from Lausanne, accompanied by a guide, after visiting the rocks at the dyke, which had excited a great interest even among those who were beyond the reach of the apprehended calamity, were returning towards Bagnes,

when, accidently turning round, they beheld this terrific mountain of waters bearing down on them with overwhelming and frightful rapidity. The noise which ought to have warned them of its approach was not heard in the roar of the torrent of the Dranse, on whose banks they were journeying. The English traveller dashed his spurs into his horse, at the same time warning his guide, who was in advance with some travellers they had accidentally encountered. The whole party instantly dismounted, scrambled up the mountain, and escaped in safety, while in another instant the rushing tide swept past them at their feet in the valley below.

The artist, however, was missing, and great fears were entertained for his safety. For many hours it was believed he was lost, but it was not till some time afterwards they discovered that he had been greatly troubled by his restive mule, who, suddenly shying at a falling rock, had discovered the frightful object which was approaching, and impelled by the instinct of preservation, dashed up the mountain, without the aid of either whip or spur, thus bearing the rider out of imminent danger.

It may seem strange, that in such circumstances of exposure to a debacle, people should live on from generation to generation. But, as Captain Basil Hall remarks, "until the fatal moment of destruction arrives, or, at all events, till the hour of danger approaches, mankind, all the world over, are pretty nearly equally indifferent; and go on, dancing and singing, marrying and giving in marriage, under the very ribs of death, with as much unconcern as if they were living in perfect safety! The inhabitants of Portici and Resina, for instance, living at the base of Vesuvius,-or those of Catania, at the foot of Mount Etna, where torrent upon torrent of lava has flowed in endless succession,never dream of an eruption till the purched volcano drinks up their wells, and, in the language of Scripture, fire runs along the ground.' In like manner, I have observed the gay voluptuaries of Lima scarcely disturbed in their reckless enjoyment of life by the shock of an earthquake, which interrupted, only for a transient moment of fear and impatient prayer, their darling Tertullas;' while the ceilings and walls of their houses cracked in their ears, and church steeples toppled round them! So with ourselves: the coasts of our own country, strewed every winter with wrecks, suggest no idea of danger to the British seaman, or make him one whit less anxious to leave the wearisome land for the merry sea. Precisely in the same spirit of confident and happy security, an inhabitant of the Val de Bagnes prefers living amongst his cold, and almost barren, but much-loved, mountains, in a situation of constant danger, with which he has become familiar from his infancy, rather than dwell in perfect security in the rich adjacent plains of Lombardy."

CHAPTER VIII.
TER

THE VAL D'AOSTA—MAGNIFICENT VIEW OF MONT BLANC-ASCENT OF THE COL

DE LA SEIGNE.

CONSIDERABLE light has now been thrown on the character of mountains. Isolated they are rare, and where they do exist, they are generally, though not always, volcanic. The general disposition of mountains is in groups, or chains. For when such eminences are so arranged as to form a line or band, whose length greatly exceeds its breadth, such a disposition is called a chain, whether the line be straight or curved. Not, be it observed, that a chain of mountains is a single, unbroken, longitudinal eminence, like that formed by the connected roofs of a row of houses; on the contrary, it is very irregular, and composed of many subordinate parts. In a complete chain there are three parallel, or nearly parallel, ridges; the centre one being usually the highest. These three ridges are seldom equidistant from each other, and they are frequently united.

From the points of junction, and from different parts of the outer ridges, other chains strike off at various angles, and these, in turn, send off other ramifications, which go on dividing and diminishing in height till the last undulations are lost in the general surface of the plain. These different branches of a chain have received various and very arbitrary names. Sometimes the whole system of a chain is divided into the primary, principal, primordial, or great chain, and secondary and tertiary chains; but as in this instance the reference is chiefly geological, we say such a chain or ridge is a branch of some other chain or ridge. Thus the Apennines are a branch of the Alps.

Minor ramifications, when short, are called spurs. Whenever the main chain sends off other chains, the former is at that particular spot higher than elsewhere, so that between two consecutive elevations there is an apparent depression. Hence the summit or ridge-line of the main chain is divided into heights, which are called by such names as peaks, domes, and needles, according to their shape; while the depressions receive the general name of passes, because they are places where the passage over the chain from opposite valleys is most easily effected. These passages or passes are termel cols in the Alps, ports in the Pyrenees, and pertins in the Jura. They are also called gorges or defiles, but incorrectly; for the gorge is properly the contracted part of a valley, and the defile a very narrow passage at the foot of the mountains, or winding amongst them. The valleys which are situated between the parallel ridges of the main chain are termed longitudinal valleys; their axes, and consequently the principal water-courses, being parallel to the direction of the chain. Of this the valley of the Rhone may be taken as an example. Sometimes there is so perfect a conformity between the re-entering angles on the one side, and the salient angles on the other, that, if it were possible to bring the two sides into contact, they would perfectly correspond, so as to leave no trace of having been separated.

The other valleys, whose axes form various angles with the direction of the great chain, are the principal valleys of the country, and are usually designated by the chief rivers

.