2l8 
The Great Ice Age and Origin of the “Till” [April, 
exist between the two classes of glaciers is this : — The gla- 
ciers (properly so called) of temperate climates being the 
overflow of the neve , or the ice which is protruded below the 
snow-line, into the region where the summer thaw exceeds 
the winter snow-fall, is necessarily subject to continual 
thinning or wasting from its upper or exposed surface, and 
thus finally becomes liquefied, and is terminated by direCt 
solar aCtion. 
Many of the characteristic phenomena of Alpine glaciers 
depend upon this ; among the more prominent of which are 
the superficial extrusion of boulders or rock fragments that 
have been buried in the neve or have fallen into the crevasses 
of the upper part of the true glacier, and the final deposit of 
these same boulders or fragments at the foot of the glaciers 
forming ordinary moraines. 
But this is not all. The thawing which extrudes, and 
finally deposits the larger fragments of rock, sifts from them 
the smaller particles, the aggregate bulk of which usually 
exceeds very largely that of the larger fragments. This fine 
silt or sand thus washed away is carried by the turbid 
glacier torrent to considerable distances, and deposited 
as an alluvium wherever the agitated waters find a resting- 
place. 
Thus the debris of the ordinary modern glacier is effectively 
separated into two or more very distinct deposits, the mo- 
raine at the glacier foot consisting of rock fragments of 
considerable size, with very little sand or clay or other fine 
deposit between them, and a distant deposit of totally dif- 
ferent character, consisting of gravel, sand, clay, or mud, 
according to the length and conditions of its journey. The 
“ chips,” as they have been well called, are thus separated 
from what I may designate the filings or sawdust of the 
glacier. 
The filings from the existing glaciers of the Bernese Alps 
are gradually filling up the lake basins of Geneva and Con- 
stance, repairing the breaches made by the erosive aCtion of 
their gigantic predecessors ; those of the southern slope 
of the Alps are doing a large share in filling up the Adriatic ; 
while the chips of all merely rest upon the glacier beds 
forming the comparatively insignificant terminal moraine 
deposits. 
The same in Scandinavia. The Storelv of the Jostedal 
is fed by the melting of the Krondal, Nygaard, Bjornestegs, 
and Soldal glaciers. It has filled up a branch of the deep 
Sogne fjord, forming an extensive fertile plain at the mouth 
of its wild valley, and is depositing another subaqueous 
