WEIGHT OF ICEBERGS. 
233 
colour is a fine emerald green ; and, in cavities, 
where the light is transmitted through a portion 
of the ice, it is a brilliant blue. Many of the 
icebergs contained strata of earth and stones, and 
some were loaded with beds of rock of great thick¬ 
ness, and weighing, by calculation, from 50,000 
to 100,000 tons. One, in particular, was observed 
(if it was indeed an iceberg) that was loaded to the 
height of a ship’s mast-head with such piles of rock, 
that only a very few specks of ice were visible. I 
obtained specimens of rocks from several of these, 
which consisted of gneiss, basaltic greenstone, some 
of it strongly magnetic, granular felspar, transition 
clay-slate, hornblendic mica-slate, a kind of gra¬ 
nite, &e. 
The weight of some of the icebergs is enor¬ 
mous. One of those above mentioned, was a mile 
in circumference, or 1500 feet square, and a hun¬ 
dred feet above the level of the sea. As it was 
nearly a parallelopipedon, its weight may easily 
be determined. Had its upper surface been ex¬ 
actly horizontal, the quantity of the mass below, 
to that above the level of the water, would have 
been in the proportion of 8.2 to 1 *; but, as there 
were some irregularities, the quantity of ice below 
in this berg may be considered as seven times 
* Account of the Arctic Regions, vol. i. p. 234. 
