gently upon its unruffled surface. In other places it
is confined into a narrow channel, breaks into swift eddies and pours
in {77} boiling rapids over the jagged rocks. Over the upper rapids of
the river, Mackenzie and his men were able to run their canoes fully
laden; but lower down were long and arduous portages, rendered
dangerous by the masses of broken ice still clinging to the banks of
the river. As they neared the Great Slave Lake boisterous gales from
the north-east lashed the surface of the river into foam and brought
violent showers of rain. But the voyageurs were trained men,
accustomed to face the dangers of northern navigation.

A week of travel brought them on June 9 to the Great Slave Lake. It
was still early in the season. The rigour of winter was not yet
relaxed. As far as the eye could see the surface of the lake presented
an unbroken sheet of ice. Only along the shore had narrow lanes of
open water appeared. The weather was bitterly cold, and there was no
immediate prospect of the break-up of the ice.

For a fortnight Mackenzie and his party remained at the lake, skirting
its shores as best they could, and searching among the bays and islands
of its western end for the outlet towards the north which they knew
must exist. Heavy rain, alternating with bitter cold, caused them much
hardship. At times it froze so {78} hard that a thin sheet of new ice
covered even the open water of the lake. But as the month advanced the
mass of old ice began slowly to break; strong winds drove it towards
the north, and the canoes were presently able to pass, with great
danger and difficulty, among the broken floes. Mackenzie met a band of
Yellow Knife Indians, who assured him that a great river ran out of the
west end of the lake, and offered a guide to aid him in finding the
channel among the islands and sandbars of the lake. Convinced that his
search would be successful, Mackenzie took all the remaining supplies
into his canoes and sent back Leroux to Chipewyan with the news that he
had gone north down the great river. But even after obtaining his
guide Mackenzie spent four days searching for the outlet It was not
till the end of the month of June that his search was rewarded, and, at
the extreme south-west, the lake, after stretching out among islands
and shallows, was found to contract into the channel of a river.

The first day of July saw Mackenzie's canoes floating down the stream
that bears hi