, but reads their meaning at a glance. Above the line at which
these indications cease, the edges of the rocks are sharp and angular,
the surface of the mountain rough, unpolished, and absolutely devoid of
all those marks resulting from glacial action. On the Alps these traces
are visible to a height of nine thousand feet, and across the whole
plain of Switzerland, as I have stated, one may trace the glaciers by
their moraines, by the masses of rock they have let fall here and there,
by the drift they have deposited, to the very foot of the opposite
chain, where they have dropped their boulders along the base of the
Jura. Ascending that chain, one finds the grooved, polished, and
scratched surfaces to its summit, on the very crest of which boulders
entirely foreign to the locality are perched. Follow the range down upon
the other side and you find the same indications extending into the
plains of Burgundy and France beyond.

With a chain of evidence so complete, it seems to me impossible to deny
that the whole space between the opposite chains of the Alps and the
Jura was once filled with ice; that this mass of ice completely covered
the Jura, with the exception of a few high crests, perhaps, rising
island-like above it, and mounted to a height of some nine thousand feet
upon the Alps, while it extended on the one side into the northern plain
of Italy, filling all its depressions, and on the other down to the
plains of Central Europe. The only natural inference from these facts
is, that the climatic conditions leading to their existence could not
have been local; they must have been cosmic. When Switzerland was
bridged across from range to range by a mass of ice stretching southward
into Lombardy and Tuscany, northward into France and Burgundy, the rest
of Europe could not have remained unaffected by the causes which induced
this state of things.

It was this conviction which led me to seek for the traces of glaciers
in Great Britain. I had never been in the regions I intended to visit,
but I knew the forms of the valleys in the lake-country of England, in
the Highlands of Scotland, and in the mountains of Wales and Ireland,
and I was as confident that I should find them crossed by terminal
moraines and bordered by lateral ones, as if I had already seen them.

The reader must not suppose, when I describe these walls, formed of the
_debris_ of the glacier, as consisting of boulders, stones, pebbles,
sand, and gravel, a