ard with the finer ones, that is,
with the sand, gravel, and mud accumulated at the bottom of the glacier,
the component parts of this underlying bed of _debris_ will be mixed
together without any reference to their size or weight. The softest mud
and finest sand may be in immediate contact with the bottom of the
valley, while larger rocks and pebbles may be held in the ice above; or
their position may be reversed, and the coarser materials may rest
below, while the finer ones are pressed between them or overlying them.
In short, the whole accumulation of loose _debris_ under the glacier,
resulting from the trituration of all kinds of angular fragments
reaching the lower surface of the ice, presents a sort of paste in which
coarser and lighter materials are impacted without reference to bulk or
weight. Those fragments which are most polished, rounded, grooved, or
scratched, have travelled longest under the glacier, and are derived
from the hardest rocks, which have resisted the general crushing and
pounding for a longer time. The masses of rock on the upper surface of
the glacier, on the contrary, are carried along on its back without
undergoing any such friction. Lying side by side, or one above another,
without being subject to pressure from the ice, they retain, both in the
lateral and medial moraines, and even in the terminal moraines, their
original size, their rough surfaces, and their angular form. Whenever,
therefore, a glacier melts, it is evident that the lower materials will
be found covered by the angular surface-materials now brought into
immediate contact with the former in consequence of the disappearance of
the intervening ice. The most careful observations and surveys have
shown this everywhere to be the case; wherever a large tract of glacier
has disappeared, the moraines, with their large angular boulders, are
found resting upon this bottom layer of rounded materials scattered
through a paste of mud and sand.

We shall see hereafter how far we can follow these traces, and what they
tell us of the past history of glaciers, and of the changes the climates
of our globe have undergone.

* * * * *

STEPHEN YARROW.

A CHRISTMAS STORY.

Sometime in the year 1856, a family named Yarrow moved into the
neighborhood where I then lived, and rented a small house with a bit of
ground attached to it, on one of the rich bottom-farms lying along the
eastern shore of the Ohio. The