The following table, extracted from the second Re port respecting the Port of London, shows the state of the tides near that city.
Above London Bridge the tide flows 18 miles to Richmond ; but the authority of the Corporation of Lon don, as conservators, by acts t4 and t7 Geo. III. extends to tne City Stone, half a mile above Staines, and 37 miles from London Bridge by water, though only 16 by land. In this distance there have been considerable im provements attempted by ballasting, and contracting the channel over shoals, and establishing regular flashes of water from the ponds and mill-dams in the upper part of the river. A horse towing-path has also been formed from Putney Bridge upwards. Still it was found neces sar), in the 50 Geo. Ill. to obtain an act for making four pond locks, viz. at Teddington, Sunbury, Stowers Gut, and Laleham, with opening weirs to pen up the water to 3 feet tO inches. A toll of 4d. per ton for a voyage, was granted for these purposes.
On the north shore at Brentford is the southern termi nation of the Grand Junction Canal, one branch of which reaches the metropolis at Paddington, and, by the Re gent's Canal, communicates by the northcrn skirts of London %shit the Thames at Limehouse. TI);s Grand Junction Canal connects London with all the great navi gations of the central and northern parts of England. On the south sln re of the Thames at Vauxnall, the Grand Suriey Canal is intended to join the Thames ; and at Wandsworth entrance is the commencement ef the iron railway to Croydon. Near Weyhridge, the river 1Vey navigation passes off to the south, and joins it to the Basingstoke canal, in a south-west direction.
From Staines upwards, past Windsor, NIaiden Head, Marlow, Henley, Reading, Abingdon, and Oxford, to Lechlade in Gloucestershire, a distance of 109 miles, the managements are designated by the name of the Thames and Isis navigation, by the 24 Geo. II. and 11, 25, 28, and 35 Geo. III. This has been vested in coun try gentlemen, by whom it has been improved by means ol 27 pond locks, and nearly as many side cuts, by making a horse towing path throughout the whole line of navigation, and lastly, hy ballasting various shallows, so that, as Mr. Alnutt, the superintendant, states, 3 feet
10 inches of water is now at all times secured. The size of the locks is, in general, 120 feet long and 18 feet wide. The distance from Staines to Oxford, by this navigation, is 81 miles, by the turnpike road only 42. At Lechlade, the surface of the water is 212 feet above the tideway of the SeVern, at the termination of the Stroud water canal. Between Lechlude ancl Staines, the follow ing navigations connect with the Thames: 1st, Near Reading, the river Kennet, from which the Kennet and Avon canal proceeds to Bath and the Severn. At Abing don, the Wilts and Berks canal proceeds westward, unites with the Kennet and Avon, and likewise sends a branch (the North Wilts canal) to rejoin the Thames near Lech lade. At Oxford, the Oxford canal passes northward, and unites with the canals of the central district. While, at Lechlade, the Thames and Severn canal passes west ward, crosses the central ridge of the island by the Sap perton tunnel of 4300 yards in length, and descends into the Stroud canal, which falls into the tiver Severn.
The tolls are 3d. per ton per voyage for each pond lock, or 6s. 9d. for the whole between Staines and Lech lade, besides a small toll of 2s. per ton for the whole length, for weir owners. The following'table from Mr. ^ilnutt's pamphlet deserves notice.
Reserving the three great junction canals, we shall pro ceed to those navigable branches of canals or rivers which are connected with the Thames.
The side cuts and pond locks up the river Wey, in Surrey, between Guildford and the Thames, are said to have been amongst the first in England, and constructed by Sir Richard Weston, in 1651. In this distance, there is a rise of 861 feet in 171 miles, and front thence to Go dalming, 2i miles, a canal rises 321 feet. The vessels employed are 70 feet long and 12 feet wide, and 3 deep, and carry 45 tons. The imports are, coals, fir timber, bale goods, tallow, and groceries. The exports are, chalk, oak timber bark, hoops, paper, malt, flour.