Preliminary Observations--The South Devon Railway--Description of the Atmospheric System--History of its Introduction prior to 1844--_Report by Mr. Brunel, recommending its Adoption on the South Devon Railway_ (August 19, 1844)--Examination of this Report--Mr. Brunel’s Evidence before the Select Committee on Atmospheric Railways, 1845--History of the Application of the System on the South Devon Railway, 1844-1848--_Report on State of Works_ (August 28, 1847)--_Report on Causes of Failure_ (August 19, 1848)--Abandonment of the System, September 1848--_Note_: Comparison of Stationary and Locomotive Power.....131 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 CHAPTER VIII. _STEAM NAVIGATION. THE ‘GREAT WESTERN’ STEAM-SHIP._ A D. 1835--1847. ÆTATIS 30--42. Introduction to the Chapters on Steam Navigation--Formation of the Great Western Steam-Ship Company--Commencement of the Building of the ‘Great Western’--_Report on Selection of the Builders of the Engines_ (June 18, 1836)--Statements of Dr. Lardner on the probable Failure of a line of Steam-ships between England and America--Voyage of the ‘Great Western’ to London--Completion of the Engines--Her return to Bristol--Fire on Board, and Accident to Mr. Brunel--Voyage to New York--Comparison between the Performances of the ‘Great Western’ and the ‘Sirius’--Subsequent History of the ‘Great Western’--_Note_: Dimensions of the Ship and Engines.....231 CHAPTER IX. _STEAM NAVIGATION. THE ‘GREAT BRITAIN’ STEAM-SHIP._ A.D. 1838--1847. ÆTATIS 33--42.