_The Ohio Canal._—This canal has a length of 309 miles, extending from Cleveland on Lake Erie to Portsmouth on the Ohio river. From the former city it ascends the valleys of the Cuyahoga and Little Cuyahoga rivers, and reaches the north end of the summit-level at Akron, 38 miles from Cleveland. This portion is fed mainly from the Cuyahoga and Little Cuyahoga rivers, and has an ascent of 395½ feet, overcome by means of 44 locks. Of these, twenty-one are within 3 miles and sixteen within 1½ mile of the north end of the summit-level at Akron. Power is utilised by a number of mills, principally at the last mentioned place. The canal now enters the basin of the Tuscarawas river, and from the south end of what is known as the Portage summit-level has an uninterrupted descent to Welsport, following the Tuscarawas valley and then that of the main Muskingum river. In this distance of 112 miles there is a fall of 238·6 feet, effected by 29 locks. The low-level at Welsport is also at the foot of a continuous descent from the Licking summit, which lies to the westward, the surplus waters entering it from either direction being discharged through a side cut into the Muskingum river at Dresden. On the division extending from the Portage summit to Welsport and Dresden, there are nearly a dozen flouring-mills, using various powers, ranging usually between 15 and 50 horse-power, but in two or three cases reaching 100 and 150. From the low-level at Welsport the canal rises to the westward to the Licking summit, making an ascent of 160 feet in the 42 miles by means of nineteen locks. The water supply is derived from the Licking river at the Narrows, from one or two forks of the main river, and from the Licking reservoir. There are no returns indicating any present use of power on this section of the canal. At Newark there is a fall of 18 feet from the feeder and from the main canal to the water-surface in the north fork of the Licking river, but it is not utilised. In years past the feeder had been employed at Newark for a small woollen mill, a flouring-mill, and a sawmill, which did rather an extensive business; but they have, one after another, abandoned the use of the water power. The feeder at that point draws from the north fork, and should take its entire low-flow, but the feeder-dam is reported as leaky, and the canal has been allowed to silt up, thereby diminishing its capacity, so that the available flow of the stream is not utilised. _The Sault St. Marie Canal._—One of the most remarkable canals in the world is that known as the Sault St. Marie, or St. Mary’s Falls Canal, in the State of Michigan, which connects the waters of Lake Superior and Lake Huron, and thereby affords a means of communication between some of the most important territories and centres of population in the United States. The position of the canal is illustrated in the chapter on “Canadian Waterways.”