[ELLS & BARLOW] PROPOSED OTTAWA CANAL 175 
erally, along this part of the section between Ottawa and Montreal, are 
low and composed of marine clays. The long range of the Laurentian 
hills, intersected by the deep valleys of the Rouge, the Nation, the Lièvre 
and the Gatineau rivers, which are tributary from the north, rise in 
graceful contours in places, to elevations of 800 to 1,000 feet above the 
waters of the river; while to the south, the country is so generally level, 
that the South Nation River which joins the Ottawa, forty miles below 
Ottawa City, takes its rise within little more than a mile of the St. Law- 
rence, in the vicinity of Brockville. The soil in this area is for the most 
part excellent, though several extensive deposits of peat occur, destined 
probably at no very distant day to be of considerable economic value- 
Above the city of Ottawa to the Chats the nearly horizontal beds of the 
Calciferous and Chazy formations are well exposed, especially along the 
south shore, and in places contain extensive beds of limestone, excellently 
suited for building purposes. The rapids and falls of the Chaudière, at 
Ottawa itself, are caused by the heavy ledges of Trenton limestone which 
here cross the river and on which the city of Hull on the north, and, to 
a certain extent, Ottawa, on the south bank, are built. 
Above the Chats Falls and rapids, which are produced by a rocky 
barrier of crystalline limestone intersected by several heavy dykes of 
syenite rock, the principal of which is seen to cause the Fall itself, the 
areas of these sedimentary rocks are quite limited till we reach the head 
of the Calumet Island channel. Beyond this however to the head of the 
Allumette Island and on the south side of the river adjacent, the beds of 
Chazy and lower Trenton have a very considerable development. Hills 
of granitic and syenitic gneiss rise on the north, almost from the shore of 
the river, while broad stretches of sand occur which overlie the marine 
clays of the district. From Pembroke west to the Mattawa these sands 
are widespread and occupy extensive areas, through which isolated masses 
of the syenitic and granitic rock protrude. Upon these latter also at 
widely separated intervals, outliers of fossiliferous Silurian strata are 
found, which have escaped the great denudation which affected the whole 
of this area. 
It would appear from the presence of these sedimentary formations 
along the present channel of the Ottawa, that the valley itself must have 
been formed at a very early date, and in fact that it constituted a chief 
outlet for the drainage of these portions of the continent from early 
Archean times. 
Along the projected route of the canal system the summit level is 
found near the western end of the section at Trout Lake, 348 miles west 
of Montreal. or 82 miles east of the eastern terminus at the outlet of 
French River, in Georgian Bay, and the elevation here is 667 feet above 
sea level, that of the surface of Lake Huron being 5813 feet; while the 
low water level of the River Ottawa, at the junction with the Mattawa, 
308 miles west of Montreal, is 498°9 feet. The elevations for the various 
