these, as well as the flat isles, must have broken off from substances
like themselves, that is, from some large tract of ice.

When I consider the vast quantity of ice we saw, and the vicinity of the
places to the Pole where it is formed, and where the degrees of
longitude are very small, I am led to believe that these ice-cliffs
extend a good way into the sea, in some parts, especially in such as are
sheltered from the violence of the winds. It may even be doubted if ever
the wind is violent in the very high latitudes. And that the sea will
freeze over, or the snow that falls upon it, which amounts to the same
thing, we have instances in the northern hemisphere. The Baltic, the
Gulph of St Laurence, the Straits of Belle-Isle, and many other equally
large seas, are frequently frozen over in winter.[12] Nor is this at all
extraordinary, for we have found the degree of cold at the surface of
the sea, even in summer, to be two degrees below the freezing point;
consequently nothing kept it from freezing but the salt it contains, and
the agitation of its surface. Whenever this last ceaseth in winter, when
the frost is set in, and there comes a fall of snow, it will freeze on
the surface as it falls, and in a few days, or perhaps in one night,
form such a sheet of ice as will not be easily broken up. Thus a
foundation will be laid for it to accumulate to any thickness by falls
of snow, without its being at all necessary for the sea-water to
freeze. It may be by this means these vast floats of low ice we find in
the spring of the year are formed, and which, after they break up, are
carried by the currents to the north. For, from all the observations I
have been able to make, the currents every where, in the high latitudes,
set to the north, or to the N.E. or N.W.; but we have very seldom found
them considerable.

[Footnote 12: Forster the elder, in his observations, has related many