PROFILE OF THE PENNSYLVANIA CANAL.
The Chesapeake and Ohio Canal, illustrated in profile, is one of the most important works of its kind in the United States, connecting the Potomac and Ohio rivers, piercing the Allegheny mountains by a tunnel 3118 feet in length, and having cost, on its completion in 1851, no less than 11,071,000 dols., or 60,000 dols. (12,001l.) per mile. The canal has a depth of 6 feet throughout. For about 60 miles it is 60 feet wide at the top, and 42 feet at the bottom; for 47 miles its surface width is 850 feet, and its bottom width, 32 feet; and for 77½ miles more the surface width is 54 feet, and the bottom width 38 feet. The locks are 100 feet long and 15 feet wide in the clear; they are capable of passing boats carrying 120 tons. There are 74 lift-locks and a tide-lock. The water-supply is drawn entirely from the Potomac, seven dams having been constructed across the river for this purpose.
PROFILE OF THE ERIE CANAL, N.Y.
PROFILE OF THE OHIO CANAL.
PROFILE OF THE CHESAPEAKE & OHIO CANAL.