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OF THE POLAR SEA. 397 
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 communi- 
cation 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 
Thlouee-tessy, 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, 
