ht times greater than that above. Wherever they are dissolved,
it is evident that the "moraine" will fall to the bottom of the sea. In
this manner may submarine valleys, mountains, and platforms become
strewed over with gravel, sand, mud, and scattered blocks of foreign
rock, of a nature perfectly dissimilar from all in the vicinity, and
which may have been transported across unfathomable abysses. If the
bergs happen to melt in still water, so that the earthy and stony
materials may fall tranquilly to the bottom, the deposit will probably
be unstratified, like the terminal moraine of a glacier; but whenever
the materials are under the influence of a current of water as they
fall, they will be sorted and arranged according to their relative
weight and size, and therefore more or less perfectly stratified.

In a former chapter it was stated that some ice islands have been known
to drift from Baffin's Bay to the Azores, and from the South Pole to the
immediate neighborhood of the Cape of Good Hope, so that the area over
which the effects of moving ice may be experienced, comprehends a large
portion of the globe.

We learn from Von Buch that the most southern point on the continent of
Europe at which a glacier comes down to the sea is in Norway, in lat.
67 degrees N.[296] But Mr. Darwin has shown, that they extend to the
sea, in South America, in latitudes more than 20 degrees nearer the
equator than in Europe; as, for example, in Chili, where, in the Gulf of
Penas, lat. 46 degrees 40 minutes S., or the latitude of central France;
and in Sir George Eyre's Sound, in the latitude of Paris, they give
origin to icebergs, which were seen in 1834 carrying angular pieces of
granite, and stranding them in fiords, where the shores were composed of
clay-slate.[297] A large proportion, however, of the ice-islands seen
floating both in the northern and southern hemispheres, are probably not
generated by glaciers, but rather by the accumulation of coast ice. When
the sea freezes at the base of a lofty precipice, the sheet of ice is
prevented from adhering to the land by the rise and fall of the tide.
Nevertheless, it often continues on the shore at the foot of the cliff,
and receives accessions of drift snow blown from the land. Under the
weight of this snow the ice sinks slowly if the water be deep, and the
snow is gradually converted into ice by partial liquefaction and
re-congelation. In this manner, islands of ice of great thickness