TELFORD, THOMAS, was one of those invaluable men whose engineering labours form the best memento of their personal history. He was the son of a shepherd in Eskdale, Dumfriesshire, where he was born in 1707. At the age of fourteen he was apprenticed to a stone-mason in the town of Langholm. In 1780, being then about twenty three, he went to Edinburgh, where he seems to have devoted much attention both to architecture and drawing. After remaining there about two years, he removed to London, and obtained employment at Somerset House, then erecting by Sir William Chambers. He was employed upon various buildings at Ports-. mouth dockyard for three years subsequent to 178I; and in 1787 he was employed by Sir William Pulteney to make some alterations • at Shrewsbury Castle. He thereupon re moved to Shrewsbury, where he was also employed to erect a new gaol, and was sub sequently appointed county surveyor, in which office he had to furnish plans for and oversee the construction of bridges and similar works. He erected the iron bridge over the Severn at Buildwas, besides about forty smaller bridges in the same county.
The Ellesmere Canal was the first great work upon which Telford was engaged ; and from 1793, in which year the act of parliament for its construction was obtained, his attention was directed almost solely to civil engineering. The aqueduct-bridge over the valley of the Dee, called the Pont-y-Cysylte, is a remark able work. It consists of a trough of cast iron plates, securely flanged together, and supported by eighteen piers or pillars of masonry, the elevation of which is 121 feet above the water. These gigantic works were executed between 1795 and 1805. The Cale, - .. • donian Canal, which was opened throughout in 1823, is another of Telford's principal works. The locks were the largest ever constructed at that tine, being 40 feet wide, and from 170 to 180 feet long. Of other canals constructed or partially under Telford's super. intendence it is sufficient to mention the Glasgow, Paisley, and Ardrossrai ; the Mac clesfield ; the Birmingham and Liverpool Junction; the Gloucester and Berkeley (com pleted tinder his direction); the Birmingham, which was completely remodelled, and adapted to the conduct of a very extensive traffic, by him; and the Weaver navigation, in Cheshire.
He also constructed a new tunnel, 2,020 yards long, 10 feet high, and 14 feet wide, at Harecastlo, on the Trent and Mersey Canal. He also executed many important works connected with the drainage of the fen country, especially of Bedford Level. On the Continent he superintended the construction of the Gotha Canal, in Sweden, a navigation of about 120 miles, of which 55 are artificial canals. For this work a Swedish order of knighthood and other honours were conferred upon him.
The works executed by Telford under the Commissioners of Highland Roads and Bridges were of great importance; and in the improvements of the great road from London to Holyhead, under another parliamentary commission, appointed in 1815, Telford had a further opportunity of carrying into effect his system of road-making. The Menai suspen sion bridge especially is a noble example of his boldness in designing and practical skill. [MENA/ BRIDGES.] Among other works of Telford are many bridges of considerable size, in which he adopted the important principle of making the spandrils hollow, and supporting the roadway upon slabs laid upon longitudinal walls, instead of filling up the haunches with a mass of loose rubbish, which often proves of serious inconvenience when the masonry of the bridge needs repair.
Telford executed some important harbour works at Aberdeen and Dundee ; but hi§ most striking performance of this class is the St. Katherine Docks, London.
In addition to the works which he executed himself, Telford was frequently applied to for his judgment upon important schemes, and in this way he made many reports to parlia ment. The Russian government frequently applied to him for advice respecting the construction of roads and canals ; and the Emperor Alexander acknowledged his sense of his services, in 1808, by sending him a diamond ring with a suitable inscription. He closed his useful life in 1834, and was buried in Westminster Abbey.