GLACIERS AND ICE. 
51 
in fig. 6, being rigidly united by regelation. From tbis novel 
ice-cup, quite liquid tight, several draughts of cooled wine can 
Fig. 5. 
easily be taken. By placing the rims of two cups together, a 
hollow sphere of ice is produced. In the same way Professor 
Tyndall has recently formed a ring of ice by merely hammering 
a plug into a suitable mould crammed with broken ice. 
Fig. 6. Fig. /. 
The application of the foregoing experiments to glaciers is 
obvious. Professor De la Rive in his inaugural address, as 
president for this year of the Swiss Society of Natural Sciences, 
has aptly done this in the following words : 
Such is the discovery of Tyndall, which may well he thus named, parti- 
cularly in view of its consequences. For all these moulds magnified become 
the borders of the valley in which a glacier flows. Here the action of the 
hydraulic press which has served for the experiments of the laboratory is 
replaced by the weight of the masses of snow and ice collected on the summits, 
and exerting their pressure on the ice which descends into the valley. Sup- 
posing, for example, a graduated series of moulds to exist, each of which 
differs very little from the one which precedes and from that which follows 
it, and that a mass of ice could be made to pass through all these moulds in 
succession, the phenomenon would then become continuous. Instead of 
rudely breaking, the ice would be compelled to change by insensible degrees 
from the spherical to the lenticular form. It would thus exhibit a plasticity 
E 2 
