[234] Tubbing is now adopted in many cases as a substitute for brick-walling. The tubbing consists of short portions of cast-iron cylinder fixed in segments. Each weighs about 4½ cwt., is about 3 or 4 feet long, and about ⅜ of an inch thick. These pieces are fitted closely together, length under length, and form an impermeable wall along the side of the pit.
[263] During this period he was engaged on the North Midland, extending from Derby to Leeds; the York and North Midland, from Normanton to York; the Manchester and Leeds; the Birmingham and Derby, and the Sheffield and Rotherham Railways; the whole of these, of which he was principal engineer, having been authorised in 1836. In that session alone, powers were obtained for the construction of 214 miles of new railways under his direction, at an expenditure of upwards of five millions sterling.
[288] The question of the specific merits of the atmospheric as compared with the fixed engine and locomotive systems, will be found fully discussed in Robert Stephenson’s able ‘Report on the Atmospheric Railway System,’ 1844, in which he gives the result of numerous observations and experiments made by him on the Kingstown Atmospheric Railway, with the object of ascertaining whether the new power would be applicable for the working of the Chester and Holyhead Railway, then under construction. His opinion was decidedly against the atmospheric system.
[289] The Marquis of Clanricarde brought under the notice of the House of Lords, in 1845, that one Charles Guernsey, the son of a charwoman, and a clerk in a broker’s office, at 12s. a week, had his name down as a subscriber for shares in the London and York line, for £52,000. Doubtless he had been made useful for the purpose by the brokers, his employers.
[309] “When my father came about the office,” said Robert, “he sometimes did not well know what to do with himself. So he used to invite Bidder to have a wrestle with him, for old acquaintance’ sake. And the two wrestled together so often, and had so many ‘falls’ (sometimes I thought they would bring the house down between them), that they broke half the chairs in my outer office. I remember once sending my father in a joiner’s bill of about £2. 10s. for mending broken chairs.”
[324] The simple fact that in a heavy storm the force of impact of the waves is from one and a-half to two tons per square foot, must necessarily dictate the greatest possible caution in approaching so formidable an element. Mr. R. Stevenson (Edinburgh) registered a force of three tons per square foot at Skerryvore, during a gale in the Atlantic, when the waves were supposed to run twenty feet high.
[327] Robert Stephenson’s narrative in Clark’s ‘Britannia and Conway Tubular Bridges,’ vol. i. p. 27.
[329a] ‘Account of the Construction of the Britannia and Conway Tubular Bridges.’ By W. Fairbairn, C.E. London, 1849.
[329b] Mr. Stephenson continued to hold that the elliptical tube was the right idea, and that sufficient justice had not been done to it. A year or two before his death Mr. Stephenson remarked to the author, that had the same arrangement for stiffening been adopted to which the oblong rectangular tubes owe a great part of their strength, a very different result would have been obtained.
[335] ‘The Britannia and Conway Tubular Bridges.’ By Edwin Clark. Vol. II, pp. 683–4.