lly his grand obelisk was totally hidden. We went along the
mountain side for a time, and then descended to the glacier.

The surface was hard frozen, and the ice crunched loudly under our
feet. There was a hollowness and volume in the sound which require
explanation; and this, I think, is furnished by the remarks of Sir John
Herschel on those hollow sounds at the Solfaterra, near Naples, from
which travelers have inferred the existence of cavities within the
mountain. At the place where these sounds are heard the earth is
friable, and, when struck, the concussion is reinforced and lengthened
by the partial echoes from the surfaces of the fragments. The
conditions for a similar effect exist upon the glacier, for the ice is
disintegrated to a certain depth, and from the innumerable places
of rupture little reverberations are sent, which give a length and
hollowness to the sound produced by the crushing of the fragments on the
surface.

We looked to the sky at intervals, and once a meteor slid across it,
leaving a train of sparks behind. The blue firmament, from which the
stars shone down so brightly when we rose, was more and more invaded by
clouds, which advanced upon us from our rear, while before us the solemn
heights of Monte Rosa were bathed in rich yellow sunlight. As the day
advanced the radiance crept down toward the valleys; but still those
stealthy clouds advanced like a besieging army, taking deliberate
possession of the summits, one after another, while gray skirmishers
moved through the air above us. The play of light and shadow upon Monte
Rosa was at times beautiful, bars of gloom and zones of glory shifting
and alternating from top to bottom of the mountain.

At five o'clock a gray cloud alighted on the shoulder of the Lyskamm,
which had hitherto been warmed by the lovely yellow light. Soon
afterward we reached the foot of Monte Rosa, and passed from the glacier
to a slope of rocks, whose rounded forms and furrowed surfaces showed
that the ice of former ages had moved over them; the granite was now
coated with lichens, and between the bosses where mold could rest were
patches of tender moss. As we ascended a peal to the right announced the
descent of an avalanche from the Twins; it came heralded by clouds of
ice-dust, which resembled the sphered masses of condensed vapor which
issue from a locomotive.

A gentle snow-slope brought us to the base of a precipice of brown
rocks, round which we wound; the s