Page:Rivers, Canals, Railways of Great Britain.djvu/380

 point that river is navigable to Bristol, as already described under the River Avon. Its whole length is fifty-seven miles; its total rise 210 feet, effected by thirty-one locks; and its whole fall 404½ feet, effected by forty-eight locks. Its breadth at bottom is 24 feet; at the surface, 44 feet; and the least depth of water is 5 feet, but through a considerable length, 6 feet. The locks are 80 feet long, and 14 feet wide; and the barges which navigate it carry from fifty to seventy tons.

Few canals afford more specimens of deep cutting, aqueducts and tunnels, than the Kennet and Avon, and we shall proceed to enumerate them, according to the order in which they arise from Newbury to Bath. Much labour has been expended upon this part of the canal, to prevent its interference with the channels, which have been made for the purpose of conveying water to the meadows, (usually called Water Meadows,) between Newbury and Hungerford; and the River Kennet has within the same distance been three times crossed by means of weirs; once to avoid Hampstead Park, and twice to prevent its passing through the village of Kentbury. At a little distance above Hungerford the level of the canal has acquired a sufficient elevation to be carried over the Kennet by means of an aqueduct, consisting of three arches. Ascending from this aqueduct to the eastern extremity of the summit level, it is carried in its passage from thence to the western extremity through the hill at Burbage, by a great deal of deep cutting, and a tunnel of five hundred yards long and 16½ feet wide. From the extremity of this tunnel to the town of Devizes, no work of consequence occurs. From Devizes to Bath the country assusnes a more hilly and rugged character. At the former place there has been an extensive piece of deep cutting. Between the locks near Foxhanger, it has been found necessary to make very large side ponds, in which the water is permitted to expand itself after it is let out of the locks, and is thus prevented from running to waste. From Foxhanger, the line of the canal is continued through the long vale of Somerham Brook, by an expensive embankment. On leaving this vale, it proceeds along the valley of the Semington River, and at Semington is conveyed across the river by a stone aqueduct, having an arch of 30 feet span, with a long embankment at each end of it. From hence there is