ns this
enormous area of nearly half North America. These means consisted (1)
of the distribution of salt and fresh water in such a way that by
means of ocean-sailing ships explorers coming from the east could
enter through straits and bays of the sea into the heart of Canada;
and (2) the facility, on quitting the seashore, of passing up
navigable rivers in boats or canoes into big lakes, and from these
lakes into other rivers leading to other lakes. Moreover, the
different river systems approached so closely to one another that even
the Amerindians and the Eskimo, long before the white man, had
realized that they had only to pick up their light canoes and carry
them a few miles, to launch them on fresh waters which might provide
hundreds or even thousands of miles of continuous travel. These are
the celebrated "portages" of Canadian history, from the French word
_porter_, to carry, transport. Sometimes the portages were made still
easier for loaded canoes by a road being cleared through the scrub and
over the rocks, and wooden rollers placed across it. Strong men could
then easily haul a loaded canoe over these wooden rollers until it
could be launched again in the water. Often these portages were made
to circumvent dangerous rapids or waterfalls. The Indians and the
French Canadians soon learnt how to steer canoes down rushes of
water--rapids--which we should think very dangerous on an English
river; but of course many of the rivers were obstructed at intervals
by descents of water which no canoe could traverse up or down, and in
these cases a path was cut from one smooth part of the river to
another, and the canoe carried or hauled overland.

In this way the great French and British explorers found it possible
to travel by water from the Atlantic to the Pacific Ocean across a
width of land of something like 2500 miles. The only serious walking
that had to be done was the crossing somewhere or other of the Rocky
Mountains, where the streams, of course, were far too precipitate in
descent to be navigable. In the hot, dusty plains of Assiniboia and
the upper Missouri region the Amerindians had introduced horses,
obtained indirectly from Spanish Mexico, and these were of great
service to the white pioneers, especially in their pursuit of the
bison.

So much for the summer season, when the rivers were full and
overflowing, and the ground consisted of bare rock, sand, or soil
covered with vegetation; the abundance of na