granite, now ground into rocks and sand and gravel by their
slow-moving, irresistible force.

Most of the glaciers I found were upon the eastern slope of the Divide.
This is because the prevailing winter winds are from west to east.
Glaciers are formed by thawing of the exposed snow on top of the huge
deposits, the water trickling down through the moss, and freezing
solidly. Gradually, through continued thawing and freezing, the whole
drift is changed into a field of ice. The first sign of movement comes
when the mass of ice breaks away from the cliffs at its upper edges.
There is an infinitesimal downward sagging, as with incredible
deliberation it moves on with its cargo of rock and sand. But, slowly
as it moves, its power is overawing. A glacier is the embodiment of
irresistible force. Its billion-ton roller cuts a trench through the
very earth, with canyon-like walls; these latter turn upon their master
and imprison him. It tears immense granite slabs from the cliffs and
carries them along. It grinds granite into powder. I have seen water
emerging from glaciers, milk-white with its load of ground-up rocks.

By setting a straight line of stakes across the ice, I measured the
movements of some glaciers. Some progressed several feet in a year,
others traveled scarcely more than a few inches. All moved farthest
nearest the center; for, as is true of streams, there the friction of
the side walls does not retard them. They varied in width from a
hundred feet to half a mile, in depth from forty to a hundred feet.

During my first years in the Rockies, the winters were severe, with
heavy snows, and the summers unusually rainy. The low temperature and
great precipitation prevented the usual amount of thawing on the
glaciers. But there came a season as arid as any in the Sahara desert.

"It's miserable droughty," grieved the Parson one day when I met him on
top of Long's Peak. "Springs are going dry and the streams are
terrible low. See that drift down there?" Standing on Long's
overtowering summit he pointed down the Divide. "The one with black
rock at its edge. Well, sir, I've never seen that drift so small
before--not in all the thirty years I've watched it. The glaciers will
be opening up with all this hot weather! the crevasses'll widen and
split clear down to the bowels of the earth. Wal; it's an ill wind
that blows no good. This drought will make it easy for the tenderfoot
to get a good look int