LEADING DIMENSIONS OF LAKE WINNIPEG. 23 



replaced by a grove of aspens.* Near the first and 

 second Eocky Points f , the various stages of this process 

 may be inspected, from the rich alluvial flat covered with 

 trees and bounded by cliffs that once overhung the water, 

 to the pond recently cut off by a naked barrier of lime- 

 stone, pebbles, and slabs, discharging its spring floods 

 into the lake by a narrow though rapid stream. In 

 some exposed places the pressure of the ice, or power of 

 the waves in heavy gales, has forced the limestone frag- 

 ments into the woods, and heaped them round the stems 

 of trees, some of which are dying a lingering death ; 

 while others, that have been dead for many years, testify 

 to their former vitality, and the mode in which they have 

 perished, by their upright stems, crowned by the decorti- 

 cated and lichen-covered branches which protrude from 

 the stony bank. The analogy between the entombment 

 of living trees, in their erect position, to the stems of 

 Sigillarice, which rise through different layers in the coal- 

 measures, is obvious." J 



The following are the approximate leading dimensions 

 of Lake Winnipeg : 



Area of Lake 8500 square miles. 



Length, not including Play Green Lake 280 statute miles. 

 Greatest breadth ..... 57 „ „ 

 Length of coast line .... 930 „ „ 

 Approximate height above the sea . . 628 feet. 



* The fact of the formation of these detached ponds, marshes, and alluvial 

 flats, points either to a gradual elevation of the district, or to an enlarge- 

 ment of the outlet of the lake, producing a subsidence of its waters. 



f The strata at these points contain many gigantic Orthoceratites, some of 

 which have been described by Mr. Stokes in the Geological Transactions. 



X If one of the spruce firs included in the limestone debris, had its top 

 broken off, and a layer of mud were deposited over all, we should have the 

 counterpart of a sketch of Sir Henry de la Beche's Manual (p. 407). The 

 thick and fleshy rhizomata of the Calla palustris, marked with the cicatrices 

 of fallen leaves, and which are abundant in these waters, bear no very 

 distant resemblance to stigmarice. 



c 4 



