Page:The American Cyclopædia (1879) Volume III.djvu/697

 CANAL 687 the Chesapeake and Delaware. All the locks on both these canals have drop gates at the upper end. They revolve around a horizontal hollow quoin in the bottom of the upper level, instead of vertical hollow quoins on the sides of the lock. The chambers of the locks are faced with plank, which is much less injurious to the boats than cut stone faces, and is said to be less expensive to keep in repair. A comprehensive system of improvement of river navigation in connection with canals is in progress in the state of Illinois. The Illinois and Michigan canal, connecting Chicago on Lake Michigan with La Salle on the Illinois river, a distance of about 100 in., will be enlarged to a width of 160 It. at the surface and a depth of 7 ft. The Illinois river, from La Salle to its junction with the Mississippi, a distance of 220 m., with a total fall of 28 ft., will be deepened and locks constructed for the passage of boats. One lock, at Henry on this river, was completed in January, and opened in March, 1872. It is 350 ft. long and 75 ft. wide, and will admit the passage of 12 canal boats at one time. In com- mencing the work for this lock 7j- acres were enclosed by a coffer dam made of timbers and sheet piling, protected by a gravel slope on the outside, and the water drawn with a rotary pump. The dimensions of the pit excavated for the foundation of the lock were 485 by 115 ft., and averaged 6 ft. in depth. After the excava- tion 3,200 bearing piles of hard wood, from 12 to 25 ft. long and 12 in. in diameter, were driven over the bottom, and on these 11 rows of timbers 12 by 12 in. square were placed longitudinally, extending 477 ft., and bolted to the piles. On these timbers transverse ones of the same cross dimensions were placed 6 in. apart and bolted, and all the spaces were filled with hydraulic concrete. The whole founda- tion was then covered with 2 inch plank secured to the timbers. The walls of the lock are built of magnesian limestone laid in hy- draulic cement. The water is received and discharged through culverts in the walls. The total amount of masonry used was 10,328 cubic yards. The gates are each 43 ft. wide and 24 ft. high, containing over 20,000 ft. of white oak timber and 27,000 Ibs. of wrought and cast iron. Improvements are also being made in the navi- gation of the Little Wabash river by deepening and the construction of locks. Ship Canals. The state of Michigan completed the construc- tion of a ship canal at the Sault Ste. Mario, the strait which conveys the waters of Lake Superior into Lake Huron, in 1855. This canal was 100 ft. wide at the surface and 12 ft. deep, having a lock 370 ft. long and 70 ft. wide, with a lift of 12 ft., and was one mile in length. This work is now in course of en- largement by the general government, and when completed the width at the coping of reveting walls will be 102 ft. G in. and at the surface of the water 100 ft. At a depth of 18 ft. it will be 93 ft. 6 in. wide, and on the bot- tom, at a depth of 20 ft., it will be 73 ft. 6 in. 147 VOL. in. 44 wide. The slope of the side after the wall is built, and of the rock excavation, will be 1 to 4, and the slope from 18 ft. depth to the bot- tom will be 5 to 1. There will be a system of two locks of 400 by 80 ft., and a single lock of the same dimensions, to overcome the dif- ference of level at one lift. TJie improve- ment of the navigation of the St. Lawrence river, which in some parts of its course is too rapid, was considered soon after the conquest of Canada, and the Lachine canal was pro- posed, to overcome the rapids of that name just above the city of Montreal, sometimes called the rapids of St. Louis. No practical steps were however taken till 1815, when the legislature made an appropriation for the work, which was commenced in 1821 and completed in 1826, at a total cost of $488,404. Its di- mensions at that time were 28 ft. wide at bot- tom, 48 ft. at water line, and 4 ft. deep, with 7 locks, each 100 ft. long by 20 wide; and it was 8 m. long. As early as February, 1816, a joint commission of both houses of parlia- ment of Upper Canada reported on the project of connecting Lake Erie with Lake Ontario, and upon other works connected with inland navigation; and Col. Nicol subsequently in- troduced a bill appropriating money for a com- plete survey of the best route of water com- munication between Lakes Erie and Ontario, as well as between Lake Ontario and Montreal. In 1821 a commission was appointed to con- sider the subject, and it reported in 1823 in favor of constructing the Welland canal, of such dimensions as would accommodate the class of vessels then navigating the lakes. The result of this report was the incorporation of the Welland canal company, who proposed to establish the necessary communication by a canal and railway. They intended to run up the natural waters of the Welland river and to pass across the township of Thorold, tunnelling through a high ridge of land about a mile and a half. In 1823, this plan being considered objectionable, a new one was adopted. It was determined to have the entrance at the mouth of Twelve-Mile creek, or Port Dal- housie, and the upper terminus at the Welland river, from whence the supply of water for the canal was to be drawn. A new company was formed, and in 1829, five years after the com- mencement of the work, two schooners, one of 85 tons burden, ascended the canal from Lake Ontario to the Welland river. Subse- quently the company proposed to extend the main line of the canal over the Welland river to Port Colborne, by enlarging about 5 m. of the feeder and excavating a new canal for the remaining distance of the bay. In 1851 the government approved this project and granted a loan of $200,000, and the work was com- pleted in 1853. It is now (1873) being again en- larged so that the locks shall be 270 ft. long, 45 ft. wide, and 12 ft. deep. The present dimen- sions of the Canadian canals connected with the navigation of the St. Lawrence are as follows :