By ANDREW BELL Resident Engineer


The natural navigation of the Ottawa River from the head of the Island
of Montreal to Ottawa City--a distance of nearly a hundred miles--is
interrupted between the villages of Carillon and Grenville which are
thirteen miles apart by three rapids, known as the Carillon, Chute a
Blondeau, and Longue Sault Rapids, which are in that order from east to
west. The Carillon Rapid is two miles long and has, or had, a fall of 10
feet the Chute a Blondeau a quarter of a mile with a fall of 4 feet and
the Longue Sault six miles and a fall of 46 feet. Between the Carillon
and Chute a Blondeau there is or was a slack water reach of three and a
half miles, and between the latter and the foot of the Longue Sault a
similar reach of one and a quarter miles.

Small canals limited in capacity to the smaller locks on them which were
only 109 feet long 19 feet wide, and 5 to 6 feet of water on the sills,
were built by the Imperial Government as a military work around each of
the rapids. They were begun in 1819 and completed about 1832. They were
transferred to the Canadian Government in 1856. They are built on the
north shore of the river, and each canal is about the length of the
rapid it surmounts.

[Illustration: THE GREAT DAM ACROSS THE OTTAWA RIVER, AT CARILLON.]

The Grenville Canal (around the Longue Sault) with seven locks, and the
Chute a Blondeau with one lock, are fed directly from Ottawa. But with
the Carillon that method was not followed as the nature of the banks
there would have in doing so, entailed an immense amount of rock