umbia, from a point called Glacier Station, in the Selkirk Mountains,
on the Canadian Pacific Railroad. It was during the month of August,
when all of the region was pervaded by a dense smoke occasioned by
burning forests. This glacier is a very showy one, owing to the
steepness of the side of the mountain and its great breadth. All the
glaciers that exist to-day are gradually receding, and are destined
eventually to entirely disappear, unless there is a change in
meteorological conditions, which some scientists claim will be the case
if we only wait long enough, when again all this northern country will
be covered with a great ice sheet. There is no doubt in regard to the
facts concerning a glacial period that must have existed in the ages
past. To anyone who has made a study of the subject there is not wanting
abundant evidence to prove that this northern country was at one time
enveloped with a great ice sheet of enormous thickness. The conditions
that existed to bring about such a state of things have been the subject
of much speculation by philosophers, but no one, as yet, has arrived at
any very satisfactory conclusion. Many theories have been advanced, some
of them not worth considering, while others have many things that give
them a show of plausibility. But all of them have what is said of the
Darwinian theory, "a missing link." It will be interesting, however, and
also instructive, to know what can be said in favor of a set of
conditions that would produce such momentous results.

CHAPTER XXVI.

EVIDENCES AND THEORIES OF AN ICE AGE.

There is abundant and unassailable evidence that at one time, ages ago,
a vast ice sheet covered the whole of the northern part of North
America, extending south in Illinois to a point between latitudes 37 and
38. This is the most southerly point to which the ice sheet reached.
From this point the line of extreme flow runs off in a northeasterly and
northwesterly direction. The northeasterly line is through southeastern
Ohio and Pennsylvania, striking the Atlantic Ocean about at New York,
thence through Long Island and up the coast of Massachusetts.
Northwesterly it follows the Mississippi River to its junction with the
Missouri, which it crosses at a point some miles west of this junction,
following the general course of this river a little south of it through
the States of Missouri, Nebraska, Dakota, and Montana. The lines,
especially the northeasterly one, are very ir