128 ROYAL SOCIETY OF CANADA 
again the Main Lake. At half-past eight we encamped on a Rock and 
it blowing hard we found it difficult to fix our Tent and with Risk of its 
being blown down during the Night. 
Tuesday the 31st [July]. Embarked at half-past two passed a 
Freeman with a loaded Canoe for the Red River. At half-past seven we 
arrived at the Portage du Rat which is 300 Paces. Here we breakfasted. 
We found here a Party of Indians, Muscagoes. One of the Women 
would have been beautiful in any Country. It is from this Portage 
that the Line which was to divide the United States from the British 
Possessions was to run, running from Latitude 49° West till it should 
strike the Missisippi.! “This Lake is also rendered remarkable in con- 
“sequence of the Americans having named it as the Spot from which a 
“ Line of Boundary between them and British America was to.run West 
“till it struck the Missisippi; which however can never happen, as the 
“North West Part of Lake du Bois is in Lat. 49.37 North and Long. 
“94.31 West and the Northward Branch of the Source of the Missisippi 
“is Lat. 47.38 North and Long. 95.6 West, ascertained by Mr. Thomp- 
“son? Astronomer to the North West Company who was sent expressly 
“for the Purpose in the Spring of 1798. We in the same Year deter- 
“mined the Northern Bend of the Missisouri to be in Latitude 47.2 
“ North and Longitude 101.25 West and according to the Indian accounts 
“it runs to the South of West so that if the Missisouri was considered 
“the Missisippi no Western Line could strike it.’ 
The Lake du Bois is of great extent perhaps 200 miles in Circum- 
ference and is nearly round. The Canoe Course may be 75 miles and 
is through large Islands which are of such extent as to be taken for the 
Main Land. Our Course was nearly North. The Portage du Rat is 
in Latitude 49.37 North and in Longitude 944 West. . The Lake du 
Bois discharges itself at both Ends of this Island and forms the River 
Winnipeg, which is a large Body of Water interspersed with innumer- 
able Islands causing various Channels and Interruptions of Portages and 
Rapids. At 9 we embarked and passing the Portage du Rat found our- 
selves in the River Winnipeg. After two Hours paddling we came to 
a narrow Channel called the Dalles or Straits and forming a very rapid 
Stream running between flat Rocks scantily covered with Undergrowth 
and Stunted Fir Trees. At one we landed to Dinner on a Rock. At 

1 For a full account of the complicated boundary question, see Henry (Coues), 
vol. I., p. 22, note. 
2 David Thompson (born Apr. 30, 1770, died Feb. 16, 1857), the astronomer and 
explorer of the Hudson Bay Company and :fterwards of the N. W, Company. For 
an account of him and his works, see Henry (Coues), Preface, p. xxi., xxiii. 
3? Quoted from Mackenzie (1801), p. lviii. 
