BENDING ICE. 
451 
data, to theorize as to the causes of this progression,, 
or to become the advocate of any one view to the ex- 
clusion of others. But I confess that my observations 
of the bergs, and of the ice-fields of our winter-pack, 
point to the viscous or gelid flow of Professor Forbes. 
The definition of a solid is at best comparative ; 
and I have had abundant proofs that ice, even at very 
low temperatures, undergoes molecular changes which 
modify its external configuration very largely. On 
the 20th of March, while we were imbedded in the 
floe, with a temperature many degrees below zero, one 
of those great convulsions called hummocking had 
thrown up a table eight feet in thickness by twenty 
odd in width, and in such a position that it was only 
sustained by masses of ice at its two extremities. In 
the month of May, the thermometer never having risen 
in the interval to within many degrees of the freezing- 
point, I saw the same ice-tahle completely bent down, 
its centre depressed five feet, until arrested in its de- 
scent by a new support.* 
1 I 
0 9 I Zfttt 
This beautiful illustration of the semi-solid charac- 
ter of the ice during the depths of a Polar winter, when 
* See the drawings of this ice-table on page 389. 
