246 Topographical Notices, 



The interruption in the navigation of the Ottawa, imme- 

 diately above the entrance of the Rideau Canal, extends 

 about five miles, in which, besides the Chaudiere falls, 

 there are three short rapids — the Petite Chaudiere, the 

 Remmok, and the Des Chenes, all running over a bed of 

 dark blue limestone, and making together, a descent of 

 from sixty to seventy feet. Between these rapids are short 

 spaces of navigable water, which it seems practicable to 

 connect without meeting with any unusual obstacle. 



It has, however, been suggested that the best plan to 

 improve this part of the rivei*, would be by connecting the 

 Chaudiere lake (which commences above the rapids) with 

 the Rideau Canal, thereby attaining the necessary elevation 

 by means of the first eight locks on that work. In the view 

 of affording a communication between the Rideau line of 

 navigation and the upper parts of the Ottawa, it is evidently 

 the preferable method to form the junction before descend- 

 ing to the foot of the Chaudiere rapids ; and there is also 

 every reason to believe that this would be much the cheapest 

 mode of improvement. I have attentively examined the 

 ground between the head of the raj)ids and the reservoir at 

 Dow's swamp, about two miles up the canal, from which 

 the cut would naturally be led off. Throughout the whole 

 distance, of about six miles, the ground declines gradually, 

 or in small sudden descents towards the Ottawa, without 

 any hollows or cross ridges whatever ; so that a branch 

 might be formed from the swamp to the Chaudiere lake, 

 rc(iuiring little more excavation than the necessary depth, 

 and without much winding. The Rideau Canal, at the 

 swamp, is about fifteen feet above the lake, which would 

 allow of the cut being kept entirely apart from the rock 

 near the rapid> ; and this level may be continued along 



