OF THE RIVER SAINT LAWRENCE. 



281 



value in an engineering point of view ; for the other fluctuations, arising from winds and 

 other more apparent and proximate causes, frequently eclipse and altogether conceal them. 

 But it is a remarkable fact ; and it is believed that such fluctuations, taken in connection 

 with exact observations upon the specific gravity of water, would tend to the solution of 

 the problem of the moon's mass, or of her density. And it is to be hoped that, in the 

 interest of science, similar observations may be undertaken in other lakes, in different 

 parts of the world, where, as for instance, in the Caspian Sea, which is the largest lake 

 in the world, and which has no regular outlet, it is believed that valuable information 

 could be usefully collected. 



THE OTTAW A. 



The Ottawa is a magnificent river, having three points of confluence with the St. Law- 

 rence ; one passing by Vaudreuil, entering at the foot of the Cascade Rapids, another by 

 St. Anne's, at the upper part of Lake St. Louis, about twenty-four miles above Montreal, 

 and the third opposite Varennes, thirty miles below that city. The northern stream 

 (which flows to the north, and thus insulates the district of Montreal), bifurcates near 

 the village of St. Eustachc, and further insulates the district of Laval, known by the 

 name of Isle Jesus. The two reuniting once more close to the lower confluence with the 

 St. Lawrence, both branches of the river pour down their brown, peaty-colored waters, 

 and stain the northwest side of the St. Lawrence nearly into Lake St. Peter, the blending 

 there being favored by the various currents induced by the low alluvial islands occupying 

 the river, which is about six miles wide (between Sorel and Berthier). 



From St. Anne's, passing up the Ottawa, we pursue an almost westerly course to 

 Ottawa, one hundred and ten miles above Montreal, where the Fall known as the "Chau- 

 diere," interrupts the navigation : the Fall itself, with six miles of rapid water above it, 

 having a total descent of sixty-seven feet. 



In that part of the river now described, the Ottawa receives many very important afflu- 

 ents from the northern side, draining the front and the vast plateau in rear of the Lauren- 

 tian Hills. The chief of these are the " Du Lievre," and the " Gatineau ;" the latter 

 joining close to the town of Ottawa, and having its sources as far north as the forty-eighth 

 parallel, its head waters lying closely contiguous to the head waters of the St. Maurice 

 and the Saguenay. A very limited extent of settlement has been carried out in this 

 direction, and the region is comparatively unexplored and unknown, — still less surveyed ; 

 although those who have crossed it in various directions report it as being filled with 

 uncounted lakes, which regulate the annual supply to the rivers of the whole of this vast 

 region. 



The affluents on the south side are the Petite Nation, and the Rideau Rivers ; the head 



VOL XIIT. 



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