AN ACCOUNT 



CURIOUS PHENOMENON OBSERVED ON THE 

 GLACIERS OF CHAMOUNY ; 



TOGETHER WITH 



SOME OCCASIONAL OBSERVATIONS CONCERNING THE PROPA- 

 GATION OF HEAT IN FLUIDS. 



IN an excursion which I made the last summer, in the 

 month of August, to the glaciers of Chamouny, in 

 company with Professor Pictet of Geneva, I had an 

 opportunity of observing, on what is called the Sea of 

 Ice (Mer de Glace\ a phenomenon very common, as I 

 was told, in those high and cold regions, but which was 

 perfectly new to me, and engaged all my attention. At 

 the surface of a solid mass of ice, of vast thickness and 

 extent, we discovered a pit perfectly cylindrical, about 

 seven inches in diameter and more than four feet deep, 

 quite full of water. On examining it on the inside with 

 a pole, I found that its sides were polished, and that its 

 bottom was hemispherical and well defined. 



This pit was not quite perpendicular to the plane of 

 the horizon, but inclined a little towards the south as it 

 descended; and in consequence of this inclination, its 

 mouth, or opening at the surface of the ice, was not 

 circular, but elliptical. 



From our guides I learned that these cylindrical holes 

 are frequently found on the level parts of the ice ; that 

 they are formed during the summer, increasing gradu- 



