4 On the Geo^aphy and Geology 



water*. Near high land, as in the neighbourhood of the island 

 called " The Pate," soundings have not been obtained with a line 

 of 100 fathoms. 



Few observations have been made on the height of the basin of 

 Lake Superior ; and these are without much pretension to accu- 

 racy. The lowest point in the barrier is between Point Iroquois 

 and Gros Cap ; for it has given way there, with the consequent 

 formation of the river St. Mary, its outlet. For several miles' 

 90rth and south of these promontories, the land at the present 

 day is much lower than elsewhere, and does not exceed 400 or 

 500 feet in elevation, while the dividing ridge, (the side of the 

 basin), on the north shore, is always from 1000 to 1400 feet high ; 

 as also are certain parts of the south shore, if not all. 



The summit level of water, at the source of the West Savannah 

 River, between the waters of the St. Louis and those of the Mis- 

 sissippi, has been estimated at 550 feet in Mr. Schoolcraft's Nar- 

 rative ; that source being 123 miles, by canoe route, from Lake 

 Superior, and about 70 direct. 



The highest water level on the old route to the Lake of the 

 Woods, from the Grand Portage, is in Ion. 90° M' lat. 48° 7' ; about 

 24 miles direct from the nearest point in Lake Superior, and may 

 be assumed at 614 1 feet. 



* Numerous observations on the temperature of the water of Lake Supe- 

 rior, made by Major Delafield, in June and the early part of July, furnished 



an averaee of 44° Fahrenheit. 



^ Feet. 



t Namely ; from careful estimate, the west end of the Grand Portage 



is above Lake Superior .....---- 195 



Perdris Portage of Pigeon River ...... 70 



Pigeon River, Rapids - - -..---10 



Portage into outward lake -- - - -- - - 30 



— Moose Lake - - - - - - - -15 



Great Cherry Portage - --...--150 



Muddy Portage - .-......-25 



Little Cherry Portage ......-- 80 



Culbut in Lake Rose -- 4 



Portage into East Lake of the height of land .... 35 



614 



• I could not perceive either rise or fall at the Little New Portage, nor ai the 

 Great Neiv Portage. 



