THE 



PHILOSOPHICAL MAGAZINE 



AND 



ANNALS OF PHILOSOPHY. 



. [NEW SERIES.] 



FEBRU AR Y 1829. 



XI. A Sketch of the Topography and Geology of Lake Ontario. 

 By J. J. BiGSBY, M.D. F.L. and G.S., For. Mem. Amer. 

 Phil. Soc. Sfc. 



[With a Map.] 

 [Continued from p. 15.] 



Topography of the Outlet of Lake Ontario, including the Lake 



of the Thousand Islands. 

 T^HE outlet of Lake Ontario, known as the River St. Law- 

 -*- rence, Iroquois or Cataraqui, is placed at the north-east 

 end of the lake, and runs N.E. as far as Montreal (202 miles) ; 

 with the exception of the small portion by the township of Corn- 

 wall, at the head of Lake St. Francis, and of the forty miles 

 above Montreal ; in both cases the change being to the E.N.E. 

 At present we are only concerned with the gorge of the lake, 

 the upper fifty-eight miles of the St. Lawrence, included be- 

 tween the towns of Kingston and Brockville, a space distin- 

 guished from that below by very marked features; as its breadth, 

 the form of its shores, the number of its islands, and its being 

 chiefly occupied by primitive rocks. 



Of the country surrounding the outlet I am only personally 

 acquainted with that on the Canadian shore. I am informed, 

 and I partly know, that there is little difference on either side. 

 The districts on the north are rendered rugged, unsightly, and 

 comparatively unproductive by the great prevalence of naked 

 or ill-clad ridges of rock ; they are usually only from twenty to 

 forty feet high, and very seldom rise into hills, unless it be in the 

 interior ; as about the Loughborough chain of lakes, and at 

 the sources of the Gananoque river. These ridges vary from 

 the state of complete ruin, in large angular blocks, to that of 

 round-backed and glazed mounds; — in most cases elongated 

 in a north-cast direction. They are commonly placed near 



New Series. Vo], 5. No. 20. Feb. 1829. * M each 



