We shall now proceed to &set ihe the inlets in the vi cinity el the Thames, and along the coasts of the Chan nel, until we reach the estuary of the Severn.
About 10 miles north of the Thames, the river Crouch is navigable abnut 12 miles to Hull Bridge, in Essex. The estuary of Blackwater is of more importance. From near Malden the Blackwater river turns to Coggeshall; the river Chelmer, from the same place, passes west ward to Chelmsford, where it divides. The Chelmer and Blackwater navigation (6 and 33 George III.) com mences at Collier's Reach. From low water in the basin to Heybridge Mill, on the Blackwater, 15/ miles, there is a rise of 12 feet 8 inches; from this place to the Chel mer river, at Bailey 'Mill, i»iles, the rise is 7 feet 3 inches ; thence to Chelmsford, 10; miles, the rise is 59 feet 5 inches. A short branch to lalalden has a rise of 6 feet 5i inches. The basin at Collier's Reach was opened for ships in Feb. 1796. Flom the northern side of the estuary the river Colne is navigable to Wivenhoe, where there is a dock-yard for building large ships. Smaller vessels may ascend to Colchester.
At Harwich is the Stour and the Orwell. In the for mer the tide flows 10 miles, and it is navigable 19 miles farther to Sudbury. In the latter the tide flows 13 miles to Ipswich; from whence the Stowmarket and Ipswich navigation proceeds (Acts 33 and 45 Geo. III.) 13 miles to Stowmarket. At little north of Harwich the Doben river is navigable 10 miles to Woodbridge.
On the south side of the. Thames, in the isle of Shep pey, is the mouth of the river Medway, up which the tide flowed to Maidstone in Kent, 17 miles, until about 26 years ago, when locks and weirs were constructed below that town. Near Rochester bridge, 80 gun ships lie afloat at low water, This is considerably above Chat ham dock-yard, to which this river affords a most safe and extensive harbour. Barges navigate to Maidstone, and even to Tunbridge; and a canal has been projected by the Wealds of Kent to Portsmouth. (Acts 32 and 4`2 Geo. ID.) To the south of the projecting point, named the North Foreland, the river Stour is navigable past Sandwich to the city of Canterbury, about 18 iniles ; but its mouth is so much perplexed by shifting sands as to render it unfit for large vessels, and it is otherwise of little use to Canterbury. This has led to thc projection of an arti dela! canal from that city, but it has not yet been reduced to practice, From hence, past Dover and Folkstone, the shore consists of bold chalk cliffs; afterwards, an extensive al luvial tract intervenes, until we arrive at the extremity of the South Downs range of chalk hills. This alluvial
tract seems to have been formed by the tendency of the gravel beach to drift towards Dungeness; and the river Rothe'. behind, flowing through a sandy country, between the range of chalk hills, has formed extensive deposits at its mouth. This tract was one of our eatliest subjects of embankment and chainage. The space on the east ern side of the Rothcr, named Romney Marsh, is sup posed to have been gained by the Romans. The same alluvial tract, under the name of Winchelsea and Pitt levels, extends considerably' to the west of the Rother. But it is to be regretted, that the process of embankment within this estuary, by cutting off the hack water, seems to have been the chief cause of the destruction of the several ports in it, famous in ancient times.
The river Rother is navigable through the haven of Rye, about 19 miles, to Robert's Bridge, with a branch 2-1 miles to Winchelsea Bridge. In former times, this river is said to have reached the shore at Old Romney harbour ; but in the reign of Ed. I. a ncw channel was niade to Old Rye harbour, through which the tide flowed 23 miles, and, while suffered to do so, scoured the chan nel in such a manner, as to render it useful. But, with a view of improving the navig,ation, sea sluices were constructed, and these having obstructed thc tide opera tions, the channel became clioakecl up and useless. In 1721, the sluices were removed, but the channel, it would secm, was not restored ; for, in 1726, captain Perry cut a new channel, above a mile in length, to the sea, and about two miles from the town. This was 150 feet wide at the top, and 70 at the bottom. In 1763, Mr. Smeaton recommended that the old course should be entirely shut up, and all the water turned down through one, other wise it would be choaked with silt. This recommenda tion, however, was neglected, and his prediction fulfilled ; and in consequence of this occurrence, the tonnage. which was formerly paid toward maintaining this harbour of Rye, was, by an act of parliament, in 1797, transferred to Ramsgate harbour. A new cut was afterwards made, a quarter of a mile to the westward of the old blocked-up harbour, in order to force the water through the new cut, and a pier head and jetties were constructed, capa ble of protecting vessels of 300 tons. The spring tides rise 24 feet. On the Rothe!) coals, deal, timber, and merchandise, are imported ; and oak tiniber ancl agii cultural produce exported.