M. de Saussure, determined to follow this successful example, hired eighteen guides, provided a tent, mattresses, philo sophical instruments, and provisions, and left Chamouny to ascend to the summit of Mont Blanc on the 13th of August, 1787. In order to render their expedition as safe and comfortable as the nature of it would permit, he had the precaution to have a but constructed on La Cote, where the party passed the first night; by four o'clock in the afternoon of the following day they had ascended 12,762 feet above the level of the sea, and at that vast eleva tion they excavated a hut in the frozen snow, which they covered with a tent ; in this they regaled themselves as well as they could, but M. de Saussure found the beat of the place so excessive, that he was frequently obliged to leave it, to re cover from the debility and suffocation he experienced; at seven o'clock the next morning the party proceeded on their entetrin, and at eleven they reach ed the object of their hopes, the top of the mountain ; there, lost in wonder and admiration at the variety and extent of the view on every side, this adventurous band remained three hours and a half, during which time they did not experi ence that extremity of cold felt by Dr. Paccard and his companion.
M. de Saussure, pursuing his intentions with that sagacity and method that distin guishes the genuine philosopher, had sta tioned M. Senebier at Geneva, who made similar experiments in that city at the same moment that the former was em ployed on Mont Blanc; by these means he found, that at Geneva, Reaumur's thermometer stood at 22.6 or 82 of Fah renheit's, and on the mountain in the shade at 2. 3 below the freezing point of • IT the former, or 27 of the latter, a differ ence of 45 degrees by Fahrenheit. De Luc's barometer, when on the mountain, fell to ' and at Geneva it stood at Taw 27.21Tws o ss .• and by making experiments with the same instrument, he calculated that the spot on which he made them was 15,662 feet above the level of the sea, agreeing almost exactly with the amount ascertained by Sir George Shuckburgh. The hygrometer evinced, that the air surrounding the summit contained six times less humidity than that of Geneva, to which cause he ascribed an excessive thirst, experienced by himself and the rest of the party, who were all more or less affected by the rarefaction of the air. The balls of the electrometer diverged three lines, and the electricity was posi tive on this enormous mountain, the most elevated rocks of which are granite, where M. de Saussure found at 11,392 feet from the sea, the moss.campion in bloom, and still higher the lichen sulphu rens, and lichen rupestris ; and what was a greater object of astonishment, two but.
terflies hovering near the summit.
Such was the result alt. de Saussure's labours, to which we shall add, in the words of Mr. Coxe, the following inte resting facts, derived from Friar Francis, one of the monks resident at the priory at St. Gothard. " About four years ago the Elector of Bavaria sent to the friar several barometers, thermometers, and other meteorological instruments, which has enabled him to note the variations of the atmosphere, and to form a series of observations, of which he favoured me with the following result. In the most extreme cold he ever experienced in these parts, the mercury in Reaumur's thermometer fell to 19 degrees below the freezing point, or 10 of Fahrenheit. In 1784, greatest heat on the 13th of Sep tember,it stood at 13,or 6I of Fahrenheit; greatest cold at 17°, or Sr of M. de Luc's barometer never rose higher than . . . 22 3 1 Or fell lower than . . . 20 9 9 It appeared from observations made in 1784, that the average state of the ther mometer and barometer was as follows In the same year it snowed during some part of 118 days; rained, 78 ; cloudy, 293; tempest, with hail, 12; thunder and light ning, 22; rainbow, 4; halos round the sun, 2 ; and round the moon, 2; serene days, 87." Some particulars have been collected relating to the formation of the Alps, from which it appears, that granite con stitutes their basis ; large portions of this substance are scattered in the valleys near them, detached by different causes, and conveyed to very considerable distances by their weight ; many dreadful conse quences have followed the sudden sepa ration of vast masses, of which two in stances may be mentioned that are calcu lated to excite the utmost horror. Plurs, a town containing 1500 inhabitants, three churches, and situated on the Moira, was overwhelmed on the 25th of August,1618, by the fall of part of a mountain, which was suspended in dreadful majesty above it, and in one moment for ever obliterat ed from the surface of the earth. A cloud of dust of impenetrable gloom pointed out to the survivors where the town had stood, and the cause of its ruin, as the enormousfragments of stone rushing with inconceivable rapidity through the air were ground into powder, where their sides met in collision with others; and had any of the miserable residents escap ed the crush of their habitation, suffoca tion must have terminated their exist ence. Houses, vineyards, and large trees, now cover the ruins of Plurs, and bones and various utensils are casually discover ed in digging.