ers.
But this subject is so intricate, and has already given rise to so many
controversies which could not be overlooked in this connection, that I
prefer to pass it over altogether in silence. Suffice it to say that not
only are most of the lakes of Switzerland hemmed in by transverse
moraines at their lower extremity, but the lakes of Upper Italy, at the
foot of the Alps, are barred in the same way, as are also the lakes of
Norway and Sweden, and some of our own ponds and lakes. Strange as it
may seem to the traveller who sails under an Italian sky over the lovely
waters of Como, Maggiore, and Lugano, it is, nevertheless, true, that
these depressions were once filled by solid masses of ice, and that the
walls built by the old glaciers still block their southern outlets.
Indeed, were it not for these moraines, there would be comparatively few
lakes either in Northern Italy or in Switzerland. The greater part of
them have such a wall built across one end; and but for this masonry of
the glacier, there would have been nothing to prevent their waters from
flowing out into the plain at the breaking up of the ice-period. We
should then have had open valleys in place of all these sheets of water
which give such diversity and beauty to the scenery of Northern Italy
and Switzerland, or, at least, the lakes would be much fewer and occupy
only the deeper depressions in the hard rocks.

Such being the evidences of the former extent of the glaciers in the
plains, what do the mountain-summits tell us of their height and depth?
for here, also, they have left their handwriting on the wall. Every
mountain-side in the Alps is inscribed with these ancient characters,
recording the level of the ice in past times. Here and there a ledge or
terrace on the wall of the valley has afforded support for the lateral
moraines, and wherever such an accumulation is left, it marks the limit
of the ice at some former period. These indications are, however,
uncertain and fragmentary, depending upon projections of the rocky
walls. But thousands of feet above the present level of the glacier, far
up toward their summits, we find the sides of the mountains furrowed,
scratched, and polished in exactly the same manner as the surfaces over
which the glaciers pass at present. These marks are as legible and clear
to one who is familiar with glacial traces as are hieroglyphics to the
Egyptian scholar; indeed, more so,--for he not only recognizes their
presence