led the Pierre-a-l'Echelle,
eight thousand one hundred feet high. The guides and travellers
were then bound together by a strong rope, with three or four yards
between each. We were about to advance upon the Bossons glacier.
This glacier, difficult at first, presents yawning and apparently
bottomless crevasses on every hand. The vertical sides of these
crevasses are of a glaucous and uncertain colour, but too seducing
to the eye; when, approaching closely, you succeed in looking into
their mysterious depths, you feel yourself irresistibly drawn
towards them, and nothing seems more natural than to go down into
them.

[Illustration: Passage Of The Bossons Glacier.]

You advance slowly, passing round the crevasses, or on the snow
bridges of dubious strength. Then the rope plays its part. It is
stretched out over these dangerous transits; if the snow bridge
yields, the guide or traveller remains hanging over the abyss. He
is drawn beyond it, and gets off with a few bruises. Sometimes,
if the crevasse is very wide but not deep, he descends to the
bottom and goes up on the other side. In this case it is
necessary to cut steps in the ice, and the two leading guides,
armed with a sort of hatchet, perform this difficult and perilous
task. A special circumstance makes the entrance on the Bossons
dangerous. You go upon the glacier at the base of the
Aiguille-du-Midi, opposite a passage whence stone avalanches often
descend. This passage is nearly six hundred feet wide. It must be
crossed quickly, and as you pass, a guide stands on guard to
avert the danger from you if it presents itself. In 1869 a guide
was killed on this spot, and his body, hurled into space by a
stone, was dashed to pieces on the rocks nine hundred feet below.

[Illustration: Crevasse and Bridge.]

We were warned, and hastened our steps as fast as our
inexperience would permit; but on leaving this dangerous zone,
another, not less dangerous, awaited us. This was the region of
the "seracs,"--immense blocks of ice, the formation of which is
not as yet explained.

[Illustration: View of the "Seracs".]

These are usually situated on the edge of a plateau, and menace
the whole valley beneath them. A slight movement of the glacier,
or even a light vibration of the temperature, impels their fall,
and occasions the most serious accidents.

[Illustration: View of the "Seracs".]

"Messieurs, keep quiet, and let us pass over quickly." These
words, roughly spok