264 Ice and its Natural History 



amount of snow falls at a height of from 2000 to 2500 metres 

 above the sea. The crystalline snow of the mountains takes 

 the granular form much more easily than does the flaky snow 

 of the lowlands. The snow that falls on glaciers in the winter 

 melts and disappears during summer like that on the neigh- 

 bouring lands. Snow in the higher regions which has persisted 

 through a summer passes into firn or neve. This is always 

 in clearly granular form. 



It is to Hugi that we owe most of our exact knowledge 

 and detailed description of the neve or firn, of its genesis and 

 of its metamorphoses. He built a hut on the Finsteraarfirn 

 at an elevation of 3300 metres, and inhabited it for a con- 

 siderable time for the sole purpose of studying the firn or 

 neVe" and its natural history. He traces the development of 

 the neve from the fine crystalline snow of the highest levels, 

 and observes it as it passes into glacier. At a height of 

 3000 metres the transformation has taken place at a depth 

 of 7 metres below the surface of the neve ; at an elevation of 

 2700 metres it is met with at a depth of a few feet, and at a 

 height of 2400 metres the ne"ve has passed into glacier at the 

 surface. In experimenting on the neve, he found that when 

 a hard compact mass of it was exposed to the influence of 

 rising temperature, the binding material of the grains soon 

 dissolved to water without the grains themselves being ap- 

 parently attacked at all. A lower temperature then reunites 

 the grains so that the whole appears as a uniform compact 

 mass. This shows the lower melting-point of the less pure 

 cementing mass of ice. He sums up the whole history of the 

 development of the glacier in a remarkable passage (p. 73) of 

 his work, Ueber das Wesen der Gletschcr. All the changes 

 which we witness taking place on the incline between the 

 most elevated neve" and the lowest extremity of the glacier 

 in the valley, are repeated on the vertical, between the upper 

 and the under surfaces of the neve and the glacier. In both 

 directions we observe greater age and more definite develop- 

 ment of the mass. Further, what we observe in both these 

 directions we observe also in the individual grain. The older 

 kernel of the neve is compact and blue like the lower glacier, 



