In building the embankment the crib-work was first put in and followed by a part (in width) of the earth-bank. From that to the shore temporary cross-dams were built at convenient distances apart and the space pumped out by sections, when the necessary excavation was done, and the walls and embankments completed. The earth was put down in layers of not more than a foot deep at a time, so that the bank, when completed, was solid. The water at site of it varied in depth from 15 feet at lower end to 2 feet at upper. The locks are 200 ft. long in the clear between the gates, and 45 ft wide in the chamber at the bottom. The walls of the lower one are 29 ft. high, and of the upper one 31 ft They are from 10 to 12 ft thick at the bottom, The locks are built similar to those on the new Lachine and Welland canals, of the very best cut stone masonry, laid in hydraulic cement. The gates are 24 in. thick, made of solid timber, somewhat similar to those in use on the St. Lawrence canals. They are suspended from anchors at the hollow quoins, and work very easily. The miter sills are made of 26 in. square oak. The bottom of the lower lock iis timbered throughout, but the upper one only at the recesses, the rock there being good. [Illustration: MAP OF THE OTTAWA RIVER AT CARILLON RAPIDS. SECTION OF RIVER AT DAM. NOTE.--THE LOWEST DOTTED LINE IS LOW WATER BEFORETHE DAM WAS BUILT. THEN THE LINE OF HIGH WATER WAS ABOUT A FOOT ABOVE WHAT IS CREST OF DAM NOW.] The rise to be overcome by the two locks is 16 ft., but except in medium water, is not equally distributed. In high water nearly the whole lift is on the upper lock, and in low water the lower one. In the very lowest known stage of the river there will never be less than 9 ft. on the miter sills. As mentioned at the beginning of this article, four locks were required on the old military canal to accomplish what is now done by two. The canal was opened in May, 1882, and has been a great success, the only drawback--although slight--being that in high water the current for about three-quarters of a mile above the upper pier, and at what was formerly the Chute a Biondeau, is rather strong. These difficulties can be easily overcome--the former by building an embankment from the pier to Brophy's Island, the latter by removing some of the natural dam of rock which once formed the "Chute." The following are, in round numbers, the quantities of the principal materials used: Earth and puddle in embankment ...cub. yds. 148,500 Rock excavation, " 38,000 Riprap, " 6,600 Lock masonry " 14,200 Rubble masonry, " 16,600 Timber in cribs, lock bottoms and gates " 368,000 Wrought and cast iron, lb ................. 173,000 Stone filling cu yds ...................... 45,300 Concrete " 830