The drainage of South Holland and Lindsey Level, towards the Witham, instead of Welland or Glen, had been an early project. In 34th Henry VIII. Charles Duke of Suffolk, and others, Commissioners of Sewers, ordered a great sewer to be made along the bounds of Kistovan and Holland, to Langrake on the Witham, with four new sluices or freestone, each eight feet wide, at Langrake, by which we may peiceive that the use of locks was not then known in England. The same scheme was renewed 17th Elizabeth, and a tax proposed for the purpose; but nothing useful was effected until 2d Charles I. when Robert, Earl of Lindsey, and others, proposed to undertake the drainage, on condition of having 20,000 acres of the land recovered. The drainage front Keyme Eau to Glen was effected by 14th Charles I.; but during the civil wars the country people took violent possession, and it was only accomplished by an act 5th George III. which authorized opening the South forty foot drain, from the Black Sluice at Boston to Hale ; and thence a new and main drain of 40 feet %vide and 6 feet deep, south wards to Guthrem, below Bourne on the Glen ; also the repairing the old and new Hammond Becks. And in 1770 an act was passed for making these cuts navigable by locks.
In 1720, Earl Fitzwilliam cut the North forty foot drain, to drain his lands on the north of the Kyme Eau. The outfall of the Witham is supposed to be thereby much injured.
The Fens on the north of the Witham appear to have been originally drained towards Waintleet, and the north Gouts above Boston. By 6th Charles I. the general drainage of that tract was undertaken by Sir Anthony Thomas, and others, for an allotment of land, and ex cepting various deep pools, it was effected in 1634.
From 1731 to 1751, the channel of the Witham had been so greatly injured, that the town of Boston was hardly accessible to vessels of 30 tons, and the naviga tion above that was entirely lost. After obtaining the opinion of various engineers, it was resolved to erect a grand sluice at the town of Boston, and to excavate a new river channel above that as Li- as Lincoln. Acts of parliament were obtained in 1761, and the work pro ceeded with. In 1766 the sea sluice %vas opened. Lang ley Edwards was engineer. The channel was in a short time greatly improved. Vessels drawing six to eight feet of water pass freely up to the town at neaps, and springs flow at the town from 12 to 15 feet. It is, how ( ver, very doubtful whether or not this improvement be attributable to the sluice.
The improvement of the channel below Boston next suggested the means of obtaining a better drainage for the adjacent Fens ; and in 1812, the plan of Mr. Rennie was carried into effect, for conveying the outfall of the Fens to a lower part of the Witham, and taking off the upper waters by a general catehwater drain round the Fen, upon a higher level.
In regard to the ultimate benefit to the navigation of the Wash, by the alteration of the course of the Wel land, we must refer to the judicious observations of Ali% Chapman, an intelligent merchant of Boston, who has puhlished some pamphlets expressly upon this important subject.
In this quarter tve must not omit noticing the Car Dyke, which skirts the uplands from the river Nene at Peterborough, to the Welland near NIarket Deeping, and front thence by Bourne and Billingham to the river Witham near Lincoln. It is a very ancient work, pro bably Roman. Its position leads us to think it has been a catch-water drain, but it might also be used for the purpose of navigating through this great extent of coun try. The portion between the rivers Nene and Wel land %vas found, by Mr. Telford's survey of that country, to be very nearly level; and, to preserve this, the line is very crooked, and is, in one instance, cut deep through a rib of land. To the north of the Welland the line is more direct, and it has a gentle declivity to the river Glen, and other natural streams which intersect the corn. try.
The great drains which have been made of late years are all navigable. The South Forty Foot is an excellent canal, being about 40 feet wide at the surface of the wa ter: the length of it is about 21 miles.
The Foss Dyke canal, supposed to have been originally made by the Romans, ancl restored under Henry I. is con nected with the Witham at Lincoln. At Braybrook Mere it proceeds on one level 11 miles, to the bank ot the river Trent at Forksay, about eight miles abole Gainsborough. It is preserved at the same level by a lock, having gates pointing- in both directions. This is the bldest artificial canal in England ; but We are un certain in what manner it was anciently connected with the Trent, or even that it ever did form such a connection. In 1762,John Smeaton and John Grandy examined, and reported both with regard to the navigation and drainage. In 1782 Mr. Smeaton was again employed ; and to his Reports, vol. i. we must rcfer for particulars, obsening only, that he found merely 2 feet 8 inches of water in this canal ; that Ile recommended raising the banks, cutting. off any immediate communication with Braybrook Mere; constructing a lock at the Lincoln Summit; ernoviing the natural ford called Braybrook-head; and gaining It? inches more water in thc canal. In 1782, Mr. Smeaton found reason to change some parts of his plan; but the general objects and effects were the sante. The naviga tion has since been perfected, and the trade of the town of Lincoln is chiefly carried on by means of it.