confer upon Mr. Rennie the honour of knighthood; this offer, however, he declined. London Bridge, which he designed but did not live to execute, was finished by his sons, Mr. George and Sir John Rennie. It is built of the finest blue and white granite from Scotland and Devonshire, and consists of five semi-elliptical arches, two of 130, two of 140, and the centre one of 152½ ft. span, being perhaps the largest elliptical arch ever attempted. The beautiful stone bridge over the Tweed at Kelso, and those at Musselburgh and New Galloway, were also designed by him. When speaking of the first-named of these bridges, Mr. Rennie used often playfully to declare, that he considered himself a benefactor to his country, inasmuch as one of his earliest public works was to build a bridge across the Tweed! The iron bridges which he executed are, the one at Boston, over the Witham, with a span of 100 feet; and the noble bridge at Southwark, over the Thames, begun in 1815 and opened in 1819. The latter consists of three circular arches of equal curvature, the centre one having a span of 240, and the other two of 210 feet. The total weight of iron in the structure was 5780 tons, and the entire cost, including approaches, &c., 800,000_l._ The improvement of harbours and the construction of docks occupied much of Mr. Rennie's attention, and in these operations his diving-bell apparatus was of peculiar value. Smeaton was the first who used the diving-bell effectually for building with stone under water; the machine he employed for that purpose was, however, very defective, and could only be used in certain situations. But Rennie, by improvements in the instrument itself, and in the machinery by which its movements could be regulated,[31] was enabled to carry on masonry, and the foundations of sea-walls, piers, and quays, as well under water as above it. He first employed his apparatus in 1813, in building the East Pierhead at Ramsgate, the foundations of which were 17 feet below low water at spring tides. It was afterwards used in founding the pierheads and outer walls of the harbours at Holyhead, Howth, and Sheerness, and other works under his direction. Amongst the numerous wet docks introduced at Liverpool in 1716, and since constructed at almost all the principal sea-ports in the kingdom, Mr. Rennie executed the London Docks, and those at Leith, Dublin, Hull, and Greenock, and also the East and West India Docks, in conjunction with Jessop and Ralph Walker. He also constructed the harbours of Queensferry, Berwick, Howth, Holyhead, and that at Kingston, the largest attempted in this country. At the low water of spring tide, the depth of this harbour was 26 feet, while the area enclosed amounted to 250 acres. The breakwater at Plymouth for protecting the Sound from the swell of the sea was likewise designed by him and Mr. Whitby, and was the first and largest example of a detached breakwater in this country. One of the most useful works executed by Mr.