appear to form a circus round it. The high points seen in profile subdivide themselves in a forest of pyramids which closes the bounds of this circus, and seem destined to defend the entrance of this charming retreat, and preserve its peace and innocence. From that side, the view extends to the Gemmi, which is known by its double summit which has given it that name. But I shall not undertake to give a detail of the immense heap of mountains which is discovered from this summit, let it suffice to say that it presents the most ravishing prospect to those who delight in such beauties.

I chose this summit for my observatory, I suspended my hygrometer and my thermometer in the air to a stick which kept them in the shade, whilst I standing on the most projecting point of the rock measured with my electrometer the degree of ærial electricity. It is true that the cold north wind which then blew did not permit me to remain long in that situation, it was necessary to find out a milder temperature under cover of the rocks which surrounded our hut; but as soon as I had warmed myself, I returned again to enjoy the prospect and continue my observations. I will give an account of them in a chapter apart.

I had the chagrin of not being able to make an experiment from which I had promised myself much pleasure: that of the necessary heat to boil water at different heights. The physicians know the profound researches of M. De Luc on this subject, their precision and their exactitude leave no doubt of the results; nevertheless M. le Chevalier Shuckburgh thinks he has found out another rule.

It was interesting to repeat these experiments, particularly at such heights as no naturalist had ever attempted. For eighteen months I had been asking of M. Paul, a thermometer armed with a micrometer and adapted to a portative kettle: but the want of proper tubes, and the multiplied occupations of this excellent artist, had so retarded the execution of this instrument that it was not ready till the day before our departure. However it appeared to be in very good order, I tried it the same night and again with success at Bionassay; and I hope it will succeed equally well every where else, but at the height of the hut the lamp destined to make the water boil would not burn; it was a lamp constructed on the principles of those that M. Argand had invented, but made in a hurry, and from a bad model: the tinder which served it as a wick burned at first very well: but presently this tinder turned into coal and afterwards went out, an accident which did not happen in a thicker air. Unhappily our apparatus was disposed in such a manner that it was impossible to make our water boil on a wood fire, the only one here in our power. After then having uselessly tried this apparatus a thousand different ways, I was obliged to give up the experiment, or put it off till another opportunity.

But the beauty of the evening, and the magnificence of the spectacle, which the setting sun presented from my observatory, consoled me for this disappointment. The evening vapour which, like a light gas, tempered the sun's brightness, and half concealed the immense extent we had under our feet, formed the finest purple belt, which incircled all the western part of the horizon, whilst to the east the snows at the base of Mont Blanc coloured by this light presented the finest and most magnificent spectacle. In proportion as the vapour descended and became more dense, this belt became narrower, and of a deeper colour; and appeared at last of a blood red, at the same instant small clouds which rove above this chain, darted a light of such brightness, that they resembled flaming stars or meteors. When the night was quite set in I returned there; the sky was then perfectly clear, and without clouds, the vapours were only observable at the bottom of the vailies: the stars shining but without any tinkling, spread over the tops of the mountains an extreme feeble and pale light, but sufficient however to distinguish the masses and the distances. The repose and profound silence which reigned in this vast extent, still heightened by the imagination, inspired me with a sort of terror; it appeared to me as if I had outlived the universe, and that I saw its corpse stretched at my feet. Sorrowful as ideas of this nature are, they have a sort of charm which can hardly be resisted. I turned my looks oftener towards this obscure solitude than towards Mont Blanc, whose shining and phosphorical snows still gave the idea of movement and life; but the keenness of the air on this isolated point presently forced me to retire to the hut.

The coldest part of the evening was three quarters of an hour after sun-set, the thermometer could keep no higher than two and a half degrees above the freezing point. An hour after it got a degree higher, and another in the night, still the fire afforded us great satisfaction; indeed we scarcely should have been able to have done without it.

But this hut, this asylum of such consequence to us, deserves to be described. It was about seven feet by eight, and four in height: it was inclosed by three walls, and the rock which it was attached to served for a fourth; flat stones placed without mortar formed these walls; and the same sort of stones, supported by three or four branches of fir, composed the roof: an opening of three feet square, left in the wall, served for an entrance. Two paillasses placed on the ground served us for beds; and an open parasol placed against the entrance served us at the same time instead of a door and curtains. M. Bourrit, and still more so his son, were incommoded by the purity of the air; they did not digest their dinner, and could not eat any supper. For my part, whom the pure air does not incommode, if I use no violent exercise, I passed an excellent night in a light and quiet sleep.

When the parasol was not before the door, I could see from my bed the snows, the ices, and the rocks situated below our hut; and the rising of the moon gave to this view the most singular appearance. Our guides passed the night, some squatted in the holes of rocks, others wrapped up in cloaks and blankets, and others sat up and watched by a little fire, which they kept up with a part of the wood we brought with us.

As M. Bourrit the year before, at the same season, and in the same place, suffered severely from insupportable cold at sun-rise, it was settled that we should not set out till after six o'clock. But as soon as day began to appear, I mounted to my observatory and there waited the sun's rising. I found the view still very fine, less singular however than at the sun's setting; the vapours, less condensed, did not form in the horizon a cordon so distinct and highly coloured, but in return I observed a singular phenomenon. It was formed of rays of a fine purple, which parted from the horizon to the west, precisely opposite the sun; they were not clouds, but a sort of thin vapour homogenous substance: these rays, to the number of six, had their centre a little below the horizon, and extended to ten or twelve degrees from this centre.

We had the precaution to take a warm mess of soup as a preventative against the cold; we then made an equal division amongst our guides of provisions, precautionary clothing, and of my instruments, and in this manner set out at a quarter past six with the greatest hope of success.

Elevated as we were to one thousand four hundred and twenty-two toises above the sea, we had still one thousand toises to get up before we could attain the summit of Mont Blanc; in effect, the most exact measures allow this summit to be two thousand four hundred and twenty-six toises above the Mediterranean. Of these one thousand toises, we had to go about six hundred on the rocks of the Aiguille du Goute, and the re mainder on the snow.

1

This Aiguille, or high mountain, seen from the environs of Geneva, presents itself under a round form, straight before, and under the highest summit of Mont Blanc. The ridge of rocks which descend from it appear like blackish furrows. From our hut we could distinguish this Aiguille under the same aspect as from Geneva; but as we were very near it, it concealed from us the height of Mont Blanc; we only saw the sky above these rocks.

The rapidity of the couloirs, or hollows, is so great, that it is impossible either to get úp or down, and even if one should happen to fall, it would be found very difficult to retain one's self; one must either roll or slide to the bottom of the mountain.

This slope, by which we were to get up, as seen from Geneva, and also from our hut, appeared sharp and inaccessible; yet our guides assured us that on a near approach all these seeming difficulties would vanish: they even went so far as to say that the ascent from Bionassay to the hut was more difficult and more dangerous than what remained for us to attain the summit of Mont Blanc. It may then be easily conceived with what courage and hopes we set out.

We began by traversing not a very sloping glacier, which separated us from the base of the Aiguille, and in twenty minutes came to the first rocks of the ridge by which we were to get on this base. This ridge is rapid enough, and the broken or disunited rocks of which it is composed do not offer a very commodious path. However, we mounted them very gaily in an hour and some minutes: the temperature was such as we could desire: the air, between three and four degrees above the freezing point, was no colder than necessary not to heat us in ascending; we enjoyed the lively and encouraging pleasure to perceive our progress by the gradual decline of summits which not long before had appeared above us. I felt a most lively joy, and which perhaps may appear puerile, when after having ascended twenty-five minutes I came to discover the lake of Geneva: it was the first time I had found myself high enough on the bases of Mont Blanc to be able to perceive it. I had also the pleasure to find here two handsome plants, aretia Alpina, and aretia Helvetica. This last is extremely rare in the Alps of Savoy. When we had attained the highest part of the ridge, it was necessary to climb a steep slope of snow to get on the glacier which forms the plateau of the base of the Aiguille, and there, for the first time, we were assisted by the hands of our guides, who were always anxious to offer us their help. It was near three quarters after seven o'clock when we got on this plateau: we had flattered ourselves with the hopes of getting there sooner; and as we knew that this was but a small part of the whole of our undertaking, I thought I ought not to stop to observe the barometer.

We then passed right to the foot of the Aiguille, and were upon the point of getting to it, when we saw with much surprise a man, who did not belong to our caravan, ascending before us at the glacier of Bionassay. But this surprise changed into a cry of joy of all the cavalcade, when we discovered him to be Guidet, the brave fellow who the year before had accompanied M. Bourrit, and had gone with Marie Goutet almost to the summit of Mont Blanc: he was not at home when we sent for him; he had not begun his journey till late in the preceding evening, had got up the mountain in the night, and came by the shortest cut into the track that he knew we should take. The guides the most loaded hastened to let him have his share of the baggage, and he gaily took his place in our rank.

The glacier that we were traversing touches on one of the ridges of the Aiguille of Goute, which is by its rapidity impracticable. This ridge is separated from that which we were to follow by one of those rapid couloirs of which I have already spoken: it was necessary to traverse this couloir: the snow which covered it was still frozen, and excessively hard; happily Goutet and Gervais, who had passed there the day before in the afternoon, had found this snow softened by the sun, and had marked places in which we could put our feet. These traversings are what I most fear: if your feet fail, you have little hope of being able to keep up; but when you directly ascend or descend, if you fall it is easier to stop yourself. Guidet wanted to pass below us, in case our footing should fail, to which we would not consent, as the slope by which he had to pass in so doing was still more rapid and dangerous than where we were; and we followed the method I had used in descending the glacier of the Aiguille du Midi. Each of us placed himself between two guides, who firmly held the two extremities of one of their long sticks; this stick formed at the side of the precipice a sort of barrier on which we supported ourselves; this barrier moved with us, made our walking secure, and preserved us from all danger.

After having traversed this couloir, we attained the ridge of the rock we had to climb, and here it was that our task become difficult. We found this ridge incomparably more steep than that which had conducted us on the base of the Aiguille, the rocks of which it is formed being more incoherent, quite disunited by the injuries of the air; sometimes they rolled from under our feet; sometimes pieces came away in our hands when we laid hold of them; often not knowing where to lay hold, I was obliged to catch at the leg of the guide next before me. The ascent in some places was so steep, that sometimes this leg was level with my head: in addition to our troubles, the snow which had fallen two days before filled up the intervals of the rocks, and concealed the hard snow or ice which we found here and there under our feet. Often the middle of the ridge became absolutely impassable, in which case we were obliged to go by the sides of dangerous couloirs by which it was bounded; at other times we met interruptions in the rocks, and it was necessary to cross snow which covered slopes extremely rapid. All these obstacles augmented gradually in our approach to the summit of the Aiguille. At length, after five hours ascent, three of which passed on this fatiguing ridge, Pierre Balmat, who preceded me, seeing that not only the slope continually became more steep, but that we still found, as we advanced, a greater quantity of fresh snow, proposed that I should rest myself while he went before a little to examine what we should do. I consented with so much the more willingness, as I had not sat down since our departure in the morning: I had sometimes stopped to take breath, but always standing, supporting myself on the stick. As he advanced he kept calling to us to wait for him, and not to proceed farther till his return. After an hour's absence he returned, and informed us that the quantity of fresh snow higher up was so great, that we could not attain the summit of these rocks without extreme danger and fatigue, and that there we should be obliged to stop, because the top of the mountain, beyond the rocks, was covered with soft snow to the depth of a foot and a half, through which it was impossible to advance. His guetres, covered as high as his knees, attested the truth of this report, and the quantity of snow all round us was also a sufficient proof of it. In consequence we agreed, though with regret, to proceed no farther.

The barometer, which I had tried during this halt, only supported itself at eighteen inches, one ligne, fourteen sixteenths, and the thermometer in the shade at two and a half. At this time the barometer, observed at Geneva by M. Pictet at one hundred and fourteen feet above the lake, supported itself at twenty-six inches, eleven lignes, thirtyone thirty seconds; and the thermometer in the open air at fourteen degrees de Reau

This observation, calculated by the logarithms without regard to the temperature of the air, would give one thousand nine hundred and thirty-five toises above the sea. If we regard this temperature, in following the formula of M. De Luc, we should take off seventy-two toises; but if we adopt the principles of naturalists, who have laboured to perfect M. De Luc's, we should make a much less considerable deduction. For, according to the Chevalier Shuckburgh, we should retrench but thirty toises; and according to M. Trembley, but twenty-eight; and so the height of the place where we stopt would be one thousand nine hundred and seven toises above the sea. Although I could not make these calculations on the place itself, as I did not know the height of the barometer in the plain, I well saw that we ought to be about one thousand nine hundred toises, and I told my fellow-traveller so; and in the chagrin we felt for not having been able to complete our enterprise, it was some consolation to us to know that we had been higher than any other known observer in Europe had ever been before.

I observed the hygrometer, the electrometer, the structure of the rocks which surrounded us; I collected several samples of these rocks; we admired the immense extent of the prospect which presented itself to our view: to the south-west we could see the river Isere much beyond Chambery, and our view to the north-east extended to Gemmi, and in this demi-circle, whose diameter is about fifty leagues, we darted above the highest mountains; we could see our lake at the left of the mole, and on the right the mountains of Abondance. The Jura alone terminated our horizon to the northwest, for we saw it even above the summit of the Buet, which was more than two hundred and seventy toises below us.

Meantime our guides pressed us to return. Although the thermometer in the shade supported itself only at two, five, and that the immediate action of the sun's rays made it only amount to four, seven, yet this same sun appeared to us extremely ardent, and when we stood still we could scarcely bear it without the help of a parasol. This made our guides fearful that the late snow, half melted by its rays, would augment the difficulty of the descent. It is known that dangerous ways are more difficult in descending than mounting, and we had passed some very bad in getting up. However, by walking with care, and the help of our guides, whose strength and courage were equally admirable we returned without any accident to the plateau of the base of the Aiguille of Goute.

As I was no longer pressed for time, I observed the barometer at the border of the slope towards the lake, and its height compared, according to M. De Luc's method, with that which he then had, gives to this plateau one thousand four hundred and ten toises above our lake, or one thousand five hundred and ninety-seven above the sea, which makes about nineteen toises more than the summit of Buet. It was also a satisfaction to me to have found there a more convenient situation for divers experiments, more elevated than the Buet, and of an easier access also. This same elevation, calculated according to Mr. Trembley's formula, would be one thousand four hundred and forty-four toises above the lake, and one thousand six hundred and thirty-seven above the sea.

From thence I re-descended to the hut very slowly, and in observing at leisure the rocks over which I passed. On my arrival there I found M. M. Bourrit, who had gone before us, and who felt so little fatigued from the journey, that they were getting ready to descend to the village of Bionassay. This was the more surprising, as M. Bourrit the younger had been ill the day before, and indisposed all the night: M. Bourrit the father, always pre-occupied by the dread of the cold, from which he suffered so much the preceding year, had mounted and descended the mountain with furred shoes, in which his foot had no stability, and which rendered this excursion so much the more tiresome for him.