138 ROYAL SOCIETY OF CANADA 



south and James Bay on the north, is determined by the Montreal River 

 and its tributaries, while from the head waters of this sti-eam the height 

 of land extends southeasterly in an irregularly curving* line to the eastern 

 end of Lake Nipissing. 



To the south of the Ottawa, the St. Lawrence water-shed, for nearly 

 one hundred miles, keeps very close to the latter river, and in the vicinity 

 of Prescott and Brockville it is scarcely more than three to four miles 

 distant. Thence it curves northwesterly to the head of the Eideau chain 

 of lakes in Bedford township, continuing northward through the centre 

 of the county of Addington, and the northtn-n portions of Hastings and 

 Haliburton, and separating the waters of the Madawaska and Petawawa 

 rivers on the north from those of the Muskoka on the south, continues on 

 to meet that already described as reaching the east shore of Lake Nipissing 

 from the Montreal Eiver basin. 



The area to the north and south of the Ottawa is well watered, 

 abounding in lakes, often of large size, with many tributary streams, so 

 that the country is comparatively easy of access by canoes throughout 

 the greater part of its extent. Much of this area, especially to the south, 

 has long been opened u]) for settlement, the soil where imderlaid by the 

 Palaeozoic formation l)eing of very superior quality. The area to the 

 north, being more rugged, has been settled principally along the valleys of 

 its principal streams. 



North of the Ottawa the principal affluents are the Kippewa, Du 

 Moine, Black, Coulonge and Gatineau, with its many branches, some of 

 which have their source in lake expansions of great extent, in the vicinity 

 of the upper stretch of the river, and the Lièvre, Nation, Eouge and du 

 Nord. To the west and south the Montreal, Mattawa, Petawawa, Mada- 

 waska, Bonnechère, Mississippi, Rideau and South Nation also drain a 

 large expanse of country. Over this southern area the greater part also is 

 occupied by the crystalline rocks of Laurentian and Huronian age, the 

 Palicozoic areas apparently tilling deejil}' eroded basins in these under! j^- 

 ing rocks. 



While much of the country, on l)otli sides of the Ottawa, is greatly 

 broken by mountain mas.ses or sti'ongl}' pronounced hill features, very 

 large tracts, more particularly as we recede from the river itself, become 

 comparatively level, presenting the aspect of great sandy plains, out of 

 which hills of granitic and gneissic rock rise to considerable elevations. 

 So marked is this feature of sand distribution, with its underlying bluish- 

 gi-ay clay, that one naturally infers the presence of water at some time, 

 over the greater portion of the entire area, probably to the height of land 

 itself. This sandy character is probably best seen on the several tribu- 

 taries of the Ottawa from the north as well as along much of the Ottawa 

 itself for nearly a hundred miles below its junction with the Mattawa, 

 where for many miles the country is covered with a great thickness of 



