This canal communicates with the Thames by its main line at Brentford, and by a branch starting five miles above at Bullbridge, stretching to Paddington, from whence the Regent's Canal proceeds round the north side of London to the Thames at Limehouse, thus completing the connection between the main line and the lower part of the river. The execution of this canal necessitated the construction of many heavy works, consisting of tunnels, deep cuttings, embankments, aqueducts, reservoirs, and weirs. Of these works one of the most famous is the Blisworth Tunnel, 3080 yards in length, cut through the inferior oolite and the shales of the lias. Its internal width is 16½ feet, the depth below the water-line to the inverted arch being 7 feet, while the soffit or crown of the arch is 11 feet above the same line. The cost of this great undertaking, with all its branches and attendant works, amounted to about two millions sterling.
During the execution of this work, Mr. Jessop was also called into Ireland, and was taking an active part in carrying on the public works which had been undertaken by the authority of Parliament in that country.
The year 1793 originated several great projects, in furtherance of which Mr. Jessop's aid was secured. Amongst these were the Grantham Canal, supplied by vast artificial reservoirs, and extending from the river Trent, through a rich pasture district of the new red sandstone, winding for many miles through the broad and fertile vale of Belvoir, up to Grantham at the base of the Lincolnshire hills, the furthest point to which it is possible to penetrate in this direction.
The Barnsley Canal, which opens up an immense amount of mineral wealth in the Yorkshire coalfield, and brings it into communication with the river Calder, and the Dearn and Dove Canal; and finally, the Great Ellesmere Canal, which completes a communication between the Severn and the Mersey, and ramifies in numerous directions amongst the rugged hills and valleys of North Wales.
In the carrying on of this last named undertaking, Mr. Telford was likewise engaged under Mr. Jessop. Two of its most important works are the great aqueducts of Chirk and Pont-y-cysylte, the former of which carries the canal over the river Ceriog, at an elevation of 70 feet, while the latter carries it across the Dee at an elevation of 127 feet. The grand peculiarity in these aqueducts consisted in constructing a water-tight trough of cast iron for carrying the canal across the arches, instead of an immense puddled clay trough, as was the practice until that time in use. The execution and management of the numerous works here mentioned occupied the greater part of Mr. Jessop's time during the next few years. But the commencement of the present century was the signal for another torrent of speculation, which, in addition to canals, began now to be directed towards docks and railroads. The promoters of the first great public dock establishment employed Mr. Jessop to conduct their works, and he had the honour of completing the great project of the West India Docks, with their numerous accompanying details, in a manner which alone entitles him to rank among our most eminent engineers.
On the completion of these docks his professional services were engaged by the citizens of Bristol, to effect a great and comprehensive measure of harbour improvement, designed to place the port of Bristol at once in the foremost position with respect to commercial advantages. This was the conversion of part of the river Avon into an immense floating dock, capable of accommodating 1400 vessels. Mr. Jessop was also at this time occupied in constructing the Surrey iron railways, which consisted of a double tramroad, from the Thames at Wandsworth to the town of Croydon, with an extension from Croydon to Godstone and Merstham; they are principally remarkable as being the first public railroads constructed in the south of England. The whole of these tramroads were afterwards bought and taken up by the Brighton Railway Company. Mr. Jessop was likewise connected with the Caledonian Canal, which he was specially called upon to survey before its commencement, and of which he continued to be the consulting engineer for many years.
In concluding this brief notice of Mr. Jessop's life, it remains only to be said that with him exclusively originated the idea of taking advantage of the immense floods to which certain districts are subject, by storing these waters up for the gradual and regular supply of his canals. In addition to this he shares with Mr. Telford the honour of first using iron in the construction of the troughs of aqueducts, and for the heads, heel-posts and ribs of lock-gates, as adopted on the Caledonian and Ellesmere canals.—Memoir of William Jessop, by Samuel Hughes, C.E.
CAPTAIN HENRY KATER, F.R.S., &c.
Born April 16, 1777. Died April 26, 1835.