em, and soon got upon a
glacier which lay in their way. There was fresh snow upon the surface,
covering the ice and concealing the _crevasses_, as they are
termed--that is, the great cracks and fissures which extend in the
glaciers down through the body of the ice. The army moved on,
trampling down the new snow, and making at first a good roadway by
their footsteps; but very soon the old ice and snow began to be
trampled _up_ by the hoofs of the horses and the heavy tread of such
vast multitudes of armed men. It softened to a great depth, and made
the work of toiling through it an enormous labor. Besides, the surface
of the ice and snow sloped steeply, and the men and beasts were
continually falling or sliding down, and getting swallowed up in
avalanches which their own weight set in motion, or in concealed
crevasses where they sank to rise no more.

They, however, made some progress, though slowly, and with great
danger. They at last got below the region of the snow, but here they
encountered new difficulties in the abruptness and ruggedness of the
rocks, and in the zigzag and tortuous direction of the way. At last
they came to a spot where their further progress appeared to be
entirely cut off by a large mass of rock, which it seemed necessary to
remove in order to widen the passage sufficiently to allow them to go
on. The Roman historian says that Hannibal removed these rocks by
building great fires upon them, and then pouring on vinegar, which
opened seams and fissures in them, by means of which the rocks could
be split and pried to pieces with wedges and crowbars. On reading this
account, the mind naturally pauses to consider the probability of its
being true. As they had no gunpowder in those days, they were
compelled to resort to some such method as the one above described for
removing rocks. There are some species of rock which are easily
cracked and broken by the action of fire. Others resist it. There
seems, however, to be no reason obvious why vinegar should materially
assist in the operation. Besides, we can not suppose that Hannibal
could have had, at such a time and place, any very large supply of
vinegar on hand. On the whole, it is probable that, if any such
operation was performed at all, it was on a very small scale, and the
results must have been very insignificant at the time, though the fact
has since been greatly celebrated in history.

In coming over the snow, and in descending the rocks immedia