452 
GLACIERS. 
its tenacity more resembled glass or granite than the 
familiar ice at home, was not a solitary one. The pre- 
ceding sketch will exhibit an equally marked curva- 
ture in a larger mass, where the gravitating pressure 
v/as applied at the two extremities. 
Contorted ices, natural bridges, and, as the season 
advanced, nodding, pen- 
dulous, stalactitic hum- 
mocks, were not unfre- 
quent. These had a dou- 
ble interest, as bearing 
not only on the plastici- 
ty of ice, but on the in- 
lluence which temperature exerts upon its condition at 
points below that of congelation, 32°. 
1 have already described the only glacier which I 
had an opportunity of surveying. It reminded me of 
La Brenva; and although I overlooked the ribboned 
structure, not having seen then the detailed work of 
Professor Forbes, I recollect that it had the peculiar 
scalloped shell summit, which he has regarded as il- 
lustrative of mechanical advance. 
It was from the icebergs, however, that formed so 
characteristic a feature of the scene before us, that we 
derived our best idea of the glaciers from which they 
had come. To the eye they presented almost infinite 
diversity ; but it required very little generalization to 
reduce them all to a few simple primary forms. 
Thus the vertical fracture of the glacier, which 
would indicate the formation of a berg by debacle, 
would divide the mass into parallelopipedons or other 
rudely symmetrical solids ; and where the surfiice of 
the original plateau was parallel to its base, the de- 
tached mass would float evenly upon the waters, a 
