s from the cliffs above. As I looked over this ice-belt, losing
itself in the far distance, and covered with its millions of tons of
rubbish, greenstones, limestones, chlorite, slates, rounded and angular,
massive and ground to powder, its importance as a geological agent, in
the transportation of drift, struck me with great force.
"Its whole substance was studded with these varied contributions from
the shore; and further to the south, upon the now frozen waters of
Marshall Bay, I could recognise raft after raft from the last year's
ice-belt which had been caught by the winter, each one laden with its
heavy freight of foreign material.
"The water torrents and thaws of summer unite with the tides in
disengaging the ice-belt from the coast; but it is not uncommon for
large bergs to drive against it and carry away the growths of many
years. I have found masses that had been detached in this way, floating
many miles out at sea--long, symmetrical tables, two hundred feet long
by eighty broad, covered with large angular rocks and boulders, and
seemingly impregnated throughout with detrited matter. These rafts in
Marshall Bay were so numerous, that could they have melted as I saw
them, the bottom of the sea would have presented a more curious study
for the geologist than the boulder-covered lines of our middle
latitudes. One boulder in particular had had its origin in a valley
where rounded fragments of water-washed greenstone had been poured out
by the torrents and frozen into the coast-ice of the belt. The
attrition of subsequent matter had truncated the great egg-shaped rock,
and worn its sides into a striated face, whose scratches still indicated
the line of water-flow."
So, then, when we next meet with a huge isolated boulder on any of our
flat beaches, we may gaze at it with additional interest, when we
reflect that, perchance, it was carried thither by the ocean, countless
ages ago, from the arctic regions, on a gigantic raft of ice; after
having been, at a still more remote period, torn from its cliffs by some
mighty glacier and slowly rolled and rounded, for hundreds of years
perhaps down the scarred slopes of its native valley.
The primary cause of the intense and prolonged cold of the arctic
regions is the shortness of the time during which they are under the
influence of the sun's rays. For a few months in summer the sun shines
brightly, but, owing to the position of the globe, obliquely on the
poles
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