270 
INTERNAL STRUCTURE AND 
ice is not complete, a rise of its temperature to 
82° Fahrenheit, accompanied with thawing, re- 
duces it at once again to the condition of loose 
grains of nSvi ; but when more compact, it al- 
ways presents the aspect of a mass composed 
of angular fragments, wedged and dovetailed to- 
gether, and separated by capillary fissures, the 
flattened air-bubbles trending in the same direc- 
tion in each fragment, but varying in their trend 
from one fragment to another. There is, more- 
over, this important point to notice, — that, the 
older the neve , the larger are its composing gran- 
ules ; and where nSve passes into porous ice, 
small angular fragments are mixed with rounded 
wev<?-granules, the angular fragments appearing 
larger and more numerous, and the nSve- gran- 
ules fewer, in proportion as the neve - ice has un- 
dergone most completely its transformation into 
compact glacier-ice. These facts show conclu- 
sively that the dimensions and form of the neve- 
granules, the size and shape of the angular frag- 
ments, the porosity of the ice, the arrangement 
of its capillary fissures, and the distribution and 
compression of the air-bubbles it contains, are all 
connected features, mutually dependent. Wheth- 
er the transformation of snow into ice be the re- 
sult of pressure on'y, or, as I believe, quite as 
much the result of successive thawings and freez- 
ings, these structural features can equally be pro- 
