At Pontypool, the Brecknock and Abergavenny canal, 33d and 44th George III. passes from the main Mon mouthshire line, crossing the Avon river by an aqueduct, passing through a tunnel of S.'20 yards, and proceeding along the high ground to the west of the Uske 144 miles, and level; thence to Brecon 181 miles, with a rise of 68 feet ; thus making the whole extent of the main line from Newport about 45 miles. From this canal a rail way passes by a bridge over the Uske to Abergavenny. There is a railway branch to Uske, one to Hay, as al ready mentioned, and various others to the coal and iron works. At the iron works near Pontypool there are some lofty inclined planes.
The next navigation connected with the north shore of the Severn, is the river Wye, which falls in at Chep stow. It ascends by a very crooked course through the counties of Monmouth and Hereford, and is navigable to Hay on the eastern side of Brecknockshire, a distance nr 85 miles. At Chepstow, the tide often rises 45 feet. This renders the lower parts dangerous to navigate ; and the upper parts are incommoded by shallows. There is a horse towing-path along the river. The chief ob jects are the impottation of coals, fir timber, deals, and groceries; and the exportation of oak timber and agri cultural produce. From the Wye, near Mitchell Dean, a railway has been laid through the forest of Dean to Lydeny, on the Severn, oppcsite Berkeley, and another branch from this by Collor(' to Monmouth; and nearly opposite to the Snout' canal a third railway has been made, five miles, to the collieries in the Forest.
Having arrived again at the channel of the Severn, we find, on its southern bank, the Berkely and Glou cester canal. By this it is intended to cut off the wind ings of the river in that place, the distance by the river being. now 28 miles, whereas by the canal it will be only 181 miles. It is connected with the river at each cnd by a ship lock. The breadth of the canal is about 60 feet at the surface of the water, and the depth of water 18 feet. It crosses the Stroud canal upon the same level. The works are far advanced, and they promise to effect a very beneficial revolution in the lower part of the Severn, by transferring to the city of Glou cester a great portion of the trade of that great river, and its extensive connections. The acts for this canal are 33d, 37th, and 43d George III. Robert Alylne was originally engineer, and Thomas Telford has lately been employed.
Opposite Gloucester, branches off the IIereford canal, from the Severn to Ledbury, 18 miles. The ascent is 196 feet. At Monkside, 8-} miles distant, is the sum mit level. At Witherington Mal sh, three miles farther, there is a fall of 30 feet ; and thence to Hereford, six miles, is level. At Oxenhall there is a tunnel 2192 yards in length ; at Canon Frorne another 1320 ; and a third near Hereford 440. The acts are 31st and 33d George III. Engineer, Joseph Clowes. Trade, coal, cyder, and agricultural produce.
From the eastern bank of the Severn, at Tewksbury, branches cff the river Avon navigation, which proceeds along a crooked course through Worcestershire to Strat ford, in Warwickshire, a distance of 40 miles. The whole navigation is the property of George Perrot, Esq.
At Worcester, the Worcester and Birmingham canal passes off, but its description belongs to the central district.
A little above Worcester is the Droitwich canal. It connects with the Severn at Hawford, and terminates at Chapel Bridge, Droitwich, a distance of 51. miles, rising 591 feet by eight locks. It is supplied by salt water. Its trade consists in coals to boil the salt brine, and it is used for the export of salt. Act 8th Geo. III.
Engineer, James Bradley.
At Stourport falls in the Staffordshire and Worces tershire canal, but it also belongs to the central district.
From the western side of the river, opposite Stour port, passes off the line of the Leominster canal. Its direction is generally west ; but it is very crooked, and mostly through a very rugged country, 45-1 miles to the town of Kingston, in Herefordshire. About 20 miles in the middle part only are executed ; but this includes a very considerable aqueduct over the river Teme, with several locks, side cuttings, and embankments. The acts are 31st and 36th George III. Engineer, Thomas Dad ford.
From Stourport upwards 25 miles to Coalport, the course of the Severn is generally bounded by high steep banks, and the country on each side is hilly, so that no collateral navigation occurs in that distance. At Coal port is the lower termination of the Shropshire Canal. 'This work forms a singular epoch in the history of English canals; for the country over which it passes being extremely rugged, and its elevation high and ab rupt, and there being likewise a scarcity of water, the modes formerly practised were quite inapplicable. These difficulties suggested the adoption of a plan then lately introduced into that country by Mr. William Reynolds, at Ketley ironworks, which consisted in forming canals upon different levels, terminating at steep banks, and conveying the boats between them by means of inclined planes, constructed upon the slope of the above-men tioned banks. In pursuance of this new mode, the com mencement of the Shropshire Canal was formed by a canal about three quarters of a mile in length, along the east bank of the Severn, just above the reach of the floods, and leaving room to stack the coals between it and the river. From this level, up the face of a steep bank, was constructed an inclined plane 350 yards in length, and 207 feet in perpendicular height, with a strong double rail-road upon it, to admit boats loaded with five tons, and their carriages. From the top of the inclined plane, a level canal was made 11 miles to the bottom of the second, or windmill inclined plane. This is 600 yards in length, and 126 feet in height. From the top of this, to the top of the Rockwardine Wood inclined plane, a distance of five miles, is the summit level. 'This last mentioned plane is 320 yards in length, and 120 feet fall. Beyond this the canal extends 100 yards, which is level. At Southall Bank, three quarters of a mile from the top of the Windmill inclined plane, a branch 21 miles passes westward to Briarley Hill, where formerly there was a communication with the Coalbrook dale works, on a much lower level, by means of crates or boxes descending through pits; but in preference to that mode, inclined planes are now employed. About 1* mile from the top of the Rockwardine \Vood inclined plane, a small canal branches off to the Ketley iron works, and it was here that Mr. Reynolds, in the year 1788, constructed the first inclined plane with a fall of 73 feet, for eight ton boats. The chief purposes of the Shropshire canal are the exportation of iron and coal from the adjacent works, and the importation of lime stone for the blast furnaces. The canal was filled, and has since been supplied with water by steam engines, which drain the coal mines. The act was 28 Geo. III. The whole was designed by Mr. William Reynolds. Mr. Henry Williams was the resident engineer. It was completed in 1792.