92 THE ICE AGE IN CANADA. 



far north as latitude 61 40', on the Felly to latitude 

 62 30', longitude 135 45'. The observed bearings show 

 a convergence of direction toward the low country about 

 the confluence of these two rivers, near the site of old fort 

 Selkirk, and it is not improbable that the glaciers may 

 have here reached to the vicinity of the sixty-third 

 parallel on the one hundred and thirty-seventh meridian. 

 No traces of glaciation were observed by Mr. McConnell, 

 still further north, along the Porcupine river, nor by Mr. 

 Russell further down the main valley of the Yukon,* the 

 appearances there being, on the contrary, those of a 

 country which had long been subjected to subaerial decay, 

 and which had not been passed over either by glaciers 

 or by floating ice capable of bearing erratics. 



" Further illustration of the fact that the extreme 

 north-western part of the continent remained a land- 

 surface upon which no extensive glaciers were developed 

 even during the time of maximum glaciation, is afforded 

 by the note of Messrs. Dease and Simpson as to the 

 entire absence of boulders along the arctic coast westward 

 from the estuary of the Mackenzie river. f 



"Granting that the north-western extremity of the 

 Cordilleran glacier reached the furthest point above 

 assigned to it, we find that its extension, from the central 

 gathering-ground (or from the approximate margin of 

 this gathering-ground already given), was much shorter 

 than that obtained by the south-easterly flowing part, the 

 approximate lengths being 350 and 600 miles respectively. 

 This may be regarded as indicating either a greater 

 relative elevation of this part of the continent to the 



* Bulletin Geol. Soc. Am., p. 140. 



t Narrative of Discoveries on the North Coast of America, 1836-39, 

 p. 149. 



