CHAPTER VII.

_RAILWAY BRIDGES AND VIADUCTS._

1. Brickwork and Masonry Bridges--Hanwell Viaduct--Maidenhead Bridge--Flying Bridges--_Letter from Mr. Brunel on Bridge Construction_ (December 30, 1854)--2. Timber Bridges--Sonning Bridge--Bath Bridge--Stonehouse Viaduct--Bourne Viaduct--St. Mary’s Viaduct--Viaducts on the South Devon Railway--Ivy-bridge--Viaducts on the South Wales Railway--Newport--Landore--Viaducts on the Cornwall Railway--St. Pinnock--Viaducts on the West Cornwall and Tavistock Railways--Preservation of Timber--3. Cast-iron Bridges--_Letter on Use of Cast Iron_ (April 18, 1849)--Hanwell Bridge--Experiments on Cast-iron Girders--_Extract from Letter to Secretary of Commission on Application of Iron to Railway Structures_ (March 13, 1848)--4. Wrought-iron Bridges--Girder Bridges--Experiments on Wrought-iron Girder--Opening Bridges--Trussed Bridges--Newport Viaduct--Windsor Bridge--Chepstow Bridge--Method of Sinking the Cylinders--Description of the Main Truss--The Floating Operations--The Royal Albert Bridge at Saltash--The Centre Pier--Description of the Superstructure--The Floating and Raising of the Trusses--Opening of the Bridge by H. R. H. the Prince Consort--_Note_: Experiments on Matters connected with Bridge Construction.....171