APPENDIX.

THE CONTRACTS AND COST OF THE BRIDGES.

It will be interesting to the professional reader to possess some accountof the cost of these structures, and of the parties employed in their construc-tion. Although in large works of a novel character it is usually bad policyto proceed by contract, yet this rule was departed from under the peculiarcircumstances of this case ; and it was Mr. Stephenson’s wish from the com-mencement that the arrangement with the contractors should be principallyconfided to Mr. Fairbairn, on account of his practical knowledge of suchmatters. That gentleman had been employed by Mr. Stephenson, on his ownresponsibility, since the month of April 1845 in carrying on the preliminaryexperiments as described. But in order that he might be empowered to signcertificates, &c., it was necessary that his appointment should be sanctionedby the Board; this was accordingly done, on Mr. Stephenson’s recommen-dation, by a Board Minute, dated May 13, 1846, and he continued to super-intend the financial arrangements until May 1847, when, on account ofsome misunderstanding between him and the Board, this department wasintrusted to the Author.

Mr. Fairbairn had proposed, July 1845, to undertake the whole con-struction himself; this proposition was not, however, entertained, and inthe month of July 1846 circulars were sent to some of the principal iron-masters, Messrs. Thornycroft, Messrs. Bradley, Messrs. Bramah, Barrowsand Hall, and Walter Williams in Staffordshire , the Coalbrook Dale Com-pany in Shropshire , and the Butterley Company in Derbyshire ; and themanufacture of the plates was contracted for by these houses at per tonaccording to the weight of the plates; the average price of all the plates was151. per ton, the price of iron being then, unfortunately, remarkably high,and the iron-masters generally overwhelmed with orders. It was thoughtbetter that the Company should purchase their own iron, and themselvessupply the contractors for the construction of the tubes, in order to insurethe best quality, and that it might more immediately be subject to Mr. Ste-phenson’s examination. The iron was consequently supplied to the con-tractors throughout the construction of the bridge at 151. per ton, howeverthe market price might vary. It was important that the plates should betruly sheared by the manufacturer, to avoid subsequent expense, and great