g the eastern side of a
deep bay of the lake, passing through various channels formed by an
assemblage of rocky islands; and at sunset encamped on a projecting point
of the north main shore eight miles from Fort Providence. To the westward
of this arm, or bay of the lake, there is another deep bay that receives
the waters of a river which communicates with Great Marten Lake where the
North-West Company had once a post established. The eastern shores of the
Great Slave Lake are very imperfectly known: none of the traders have
visited them and the Indians give such loose and unsatisfactory accounts
that no estimation can be formed of its extent in that direction. These
men say there is a communication from its eastern extremity by a chain of
lakes with a shallow river which discharges its waters into the sea. This
stream they call the Thloueetessy, and report it to be navigable for
Indian canoes only. The forms of the south and western shores are better
known from the survey of Sir Alexander Mackenzie and in consequence of
the canoes having to pass and repass along these borders annually between
Moose-Deer Island and Mackenzie's River. Our observations made the
breadth of the lake between Stony Island and the north main shore sixty
miles less than it is laid down in Arrowsmith's map; and there is also a
considerable difference in the longitude of the eastern side of the bay,
which we entered.

This lake, owing to its great depth, is seldom completely frozen over
before the last week in November and the ice, which is generally seven
feet thick, breaks up about the middle of June, three weeks later than
that of the Slave River. The only known outlet to this vast body of water
which receives so many streams on its north and south shores is the
Mackenzie River.

August 3.

We embarked at three A.M. and proceeded to the entrance of the
Yellow-Knife River of the traders, which is called by the natives
Begholodessy or River of the Toothless Fish. We found Akaitcho and the
hunters with their families encamped here. There were also several other
Indians of his tribe who intended to accompany us some distance into the
interior. This party was quickly in motion after our arrival and we were
soon surrounded by a fleet of seventeen Indian canoes. In company with
them we paddled up the river, which is one hundred and fifty yards wide,
and in an hour came to a cascade of five feet where we were compelled to
make a portage of one hund