NATURAL HISTORY, 



507 



wishes for indulgence. The time 

 of my arrival was half an hour 

 after ten ; so that the hours which 

 had elapsed from our departure 

 from Chamouni were only 272> 

 10 of which we had passed in the 

 hut. The summit of the hill is 

 formed of snow, which spreads 

 into a sort of plain which is 

 much wider from E. to W. than 

 from N. to S., and in its great- 

 est width is perhaps 30 yards. 

 The snow is every where hard, 

 and in many places is covered 

 with a sheet of ice. When the 

 spectator begins to look round 

 him from this elcTated height, a 

 confused impression of jmmensity 

 is the first effect produced upon 

 his mind ; but the blue colour, 

 deep almost to blackness, of the 

 canopy above him soon arrests his 

 attention. He next surveys the 

 mountains ; many of which, from 

 the clearness of the air, are to his 

 eye within a stone's throw from 

 him ; and even those of Lombardy 

 (one of which appears of an alti- 

 tude but little inferior to that of 

 Mount Blanc) seem to approach 

 his neighbourhood ; while on the 

 other side the vale of Chamouni 

 glittering with the sunbeams is to 

 the view directly below his feet, 

 and affects his head with giddiness. 

 On the other hand, all Qbjects of 

 which the distance is great, and 

 the level low, are hid from his 

 eye by the blue vapour which in- 

 tervenes, and through which I 

 could not discern the Lake of Cie- 

 neva, though at the height of 

 1.5,700 English feet, which, ac- 

 cording to M. de Saussuie, was 

 the level on which ] stood : even 

 the Mediterranean Sea must have 

 been within the line of vision. The 

 Air was still; and the day so re- 



markably fine, that I could not 

 discover in any part of the heavens 

 the appearance of a single cloud. 

 As the time of the sun passing the 

 meridian now approached, I pre- 

 pared to take my observation. I 

 had with me an admirable Had- 

 ley's sextant, and an artificial 

 horizon, and I corrected the mean 

 refraction of the sun's rays. Thus 

 I was enabled to ascertain with 

 accuracy that the latitude of the 

 summit of Mount Blanc is 45° 49' 

 59" North. 



I now proceeded to such other 

 observations as the few instru- 

 ments which I had brought per- 

 mitted me to make. At twelve 

 o'clock the mercury in the ther- 

 mometer stood at 38° in the shade; 

 at Chamouni, at the same hour, 

 it stood when in the shade at 7S°. 

 I tried the effect of a burning 

 glass on paper, and on a piece of 

 wood, which I had brought with 

 me for the purpose, and found 

 (contrary, I believe, to the gene- 

 lally received opinion) that its 

 power was much greater than in 

 the lower regions of the air. 

 Having continued two hours on 

 the summit of the mountain, I 

 began my descent at half an hour 

 after twelve. I found that, short 

 as my absence had been, many 

 new rents were opened, and that 

 several of those which 1 had pass- 

 ed in my ascent were become con- 

 siderably wider. In less than six 

 hours we arrived at the hut in 

 which we had slept the evening 

 before, and should have proceeded 

 much further down the mountain 

 had we not been afraid of passing 

 the Glaciere de la Cote at the close 

 of the day, when the snow, from 

 the effect of the sun-beams, was 

 extremely rotten. Our evening's 



repast 



