Prof. Pictet on the Ice-caves of the Jura and the Alps. 11 
culminating point of the pass. In order to reach the grotto, 
we ascended along the foot of the rocks, in a direction perpendi- 
cular to that of the chain, and as if we proposed to cross it, by 
the pass up which we clambered, having on our right the rocks 
which form part of the central mass of the mountain. We 
found, in scrambling along the foot of the rock, a tolerably 
spacious cavern, in which tradition says, a band of coiners were 
formerly discovered. This grotto is cold, but without ice. A 
few toises higher we arrived at the ice-cave, situated in the same 
mass of rocks, but which is announced majestically by a low 
vault, 43 feet in width at the base. We were immediately sen- 
sible of an extreme degree of cold which issued from it, and 
against which it is the more necessary to take precautions, that 
it is almost impossible to reach it without being overheated. 
From the entrance the cavity becomes much wider. We de- 
scended by a gently inclined plane, at the bottom of which is a 
horizontal platform of ice, of 60 feet in length, by 30 in width ; 
it is not thick where it commences, but becomes more*so as it 
advances towards the extremity. The ice rises in a slope 
against the rock, which terminates the grotto. On the left side 
of the ice a stalagmite of the same material rises to about the 
height of two feet, formed by the water which drops from a cre- 
vice in the vault, which is not very high. 
If, after arriving at the extremity of this fine cavern, we turn 
round to look at the interior, it will present a coup-d’ceil which 
» we recommend to draughtsmen as extremely picturesque. 
The temperature at a foot above the ice was 34 °f. In 
the open air, and beyond the refrigerating influence, it was 
58°. The barometer, constructed in London, and intended 
for the English mountains, which are not so high as ours, was 
of no use in determining the height of the cavern above the 
lake; the mercury could not descend lower, the reservoir being 
full. 
Our guide informed us, that when he visited the cavern in 
April last, he found no ice, but a considerable depth of water 
towards its extremity. He praised its beauty at present, which 
he declared to be greater than he had ever witnessed. It may 
be well to remark, that the present year is very extraordinary, 
