The Sault St. Marie Canal. - The Cleveland Plaindealer gives the following description of the Canal, which is to connect Lake Huron with Lake Superior:
The length of the excavation, from water to water, is 4,340 feet, to whichis added the pier below, 308 feet long, and the pier and the bank at the head, 1,000 feet long, making the entire length of the work 5,658 feet - 378 feet more than a mile. The fall of St. Mary is 18 feet, and the canal is to be 12 feet deep. The sides are to be inclined from the canal bottom to the slope, of 1 1/2 feet to 1, and are to be walled with stone where there is not a natural wall, so that they will present a rock surface throughout.
On the canal bottom, the width is 64 feet, and consequently it is 100 feet wide. The walled banks are to rise five feet above the water line, making the breadth of the tow-path bank, 115 feet. There is a basin 400 feet long, 40 feet wider than the canal, placed about 1,000 feet above the locks. Thee are to be two locks, each 350 feet in length, between the gates, made with walls 10 feet thick at the base, and strengthened by stone buttresses on the outside, 12 feet apart. These will contain 15,000 cubic yards of masonry, of which probably 12,000 yards must be brought in vessels from a distance.
Not less than 12,000 tons of it came in schooners from Malden, near Detroit. The locks are of sufficient capacity to admit the largest steamers now floating upon our lakes. At the commencement of the work, there were 205,360 cubic yards of rock and earth to be taken out, above water. The amount now remaining is les than one sixth of this, and if the work of the present month equals that of the past, about six-tenths of the entire excavation work will be done above water, leaving something less than 3,000 yards, yet to take out.
There will also be 24,000 yards of under water excavation, to prepare for the upper pier, the greater part of which is muck and gravel. The piers below are finished above wager, and a temporary pier 300 feet in length is put up on the north side of the canal to accommodate the great freighting vessels of the company.