As to the supposition that the motion proceeded from
the sea towards the land, all the facts are against it, since the whole
trend of these phenomena is from inland centres toward the shore,
instead of being from the coast upward.
Certainly, no one familiar with the facts could suppose that floating
ice or icebergs had abraded, polished, and furrowed the bottom of narrow
valleys as we find them worn, polished, and grooved by glaciers. And it
must be remembered that this is a theory founded not upon hypothesis,
but upon the closest comparison. I have not become acquainted with these
marks in regions where glaciers no longer exist, and made a theory to
explain their presence. I have, on the contrary, studied them where they
are in process of formation. I have seen the glacier engrave its lines,
plough its grooves and furrows in the solid rock, and polish the
surfaces over which it moved, and was familiar with all this when I
found afterwards appearances corresponding exactly to those which I had
investigated in the home of the present glaciers. I could therefore say,
and I think with some reason, that "this also is the work of the glacier
acting in ancient times as it now acts in Switzerland."
There is another character of glacial action distinguishing it from any
abrasions caused by water, even if freighted with a large amount of
loose materials.
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