[120] Mr. Robert Stephenson thought it possible, that if you had a dock filled with sulphate of copper, you might treat an iron vessel as you do a small teapot, and electrotype it with a thin coating of copper. (Evidence, 1851, 26th June, before Committee of the House of Commons.)
[121] The Liverpool underwriters, in their book of registry for iron vessels (established 1862), in the edition of that work for 1863 and 1864, offer the following remarks:
“Experience has shown that iron ships are much more durable than was at first supposed. By the use of cement inside, and by careful attention to outside coating, a well constructed iron ship can be reckoned upon to last, in first-class condition, for a period of at least twenty years. Wear and tear of equipment, and of the wood used in their construction, must in all cases be excepted.”
[122] Mr. McGregor Laird states in his evidence (Question 553, p. 59) before the Select Committee on “Steam Navigation to India,” 1834, “A strong iron vessel will not weigh one-half of that of a wooden one, and therefore will draw considerably less water;” further (Q. 554), “Her capacity for stowage will be much greater, her sides, including strong iron frames, not exceeding 4 inches in thickness, while those of a wooden vessel will be 12 inches thick.”
“The average weight of the iron steam vessels is about 6 cwt. per register ton; a wooden one will weigh about 20 cwt. and upwards.”—(See evidence of C. W. Williams, Appendix to Report of the above Committee, p. 43.) See note, [Appendix No. 5, p. 599].
[123] The greatest number of years originally allowed by “Lloyd’s Register” for the classification of any vessel built of wood to remain on the first class, was from four to sixteen years, but seldom more than twelve from the date of construction; they might be renewed, but the original term never exceeded the periods I have named.
[124] Captain (now Admiral Sir) W. H. Hall, R.N., in his evidence before Lord Seymour’s (now the Duke of Somerset) Committee on Navy Estimates which sat in 1848, stated (p. 648) that, when he commanded the Nemesis, an iron vessel engaged in the Chinese war, she was in one action struck fourteen times by the shot of the enemy; “one shot went in at one side and came out at the other, it went right through the vessel;” there were “no splinters;” “it went through just as if you put your finger through a piece of paper.” “I had,” he added, “a favourable opinion of it” (iron). “Several wooden steamers,” he continues, “were employed upon the same service, and they were invariably obliged to lie up for repairs, whilst I could repair the Nemesis in twenty-four hours and have her always ready for service; indeed, many steamers were obliged to leave the coast of China and go to Bombay for repairs. Repairs which would have taken in a wooden ship several days, would take in ours as many hours only.”
Captain E. F. Charlwood, who had served in iron vessels “about four or five years,” stated, in his evidence before the same Committee, that the Guadaloupe, which he commanded, had been repeatedly struck by shot, and that “the damage was considerably less than is usually suffered by a wooden vessel,” and that “there was nothing like the number of splinters which are generally forced out by shot sent through a wooden vessel’s side.” He added that the shot went clean through (the holes being plugged by the engineer at the time), and did not otherwise injure the plates or leave a rent or displace any of the rivets.
[125] The author moved that the vote should be reduced by 300,000l. (see “Hansard’s Parliamentary Report” for May 23rd, 1861, page 30, where his reasons are given), but, after a long debate, he was defeated, only thirty members voting with him, and sixty-six against any reduction. The reader will find what became of this timber (a large portion lay rotting in the dock-yards) if he refers to the Report of the Committee, appointed on the motion of Mr. Seely, some years afterwards. But, beyond the reasons then given by the author, the Admiralty or their practical advisers must have known, long before 1861, that a screw-ship built of wood was vastly inferior to one constructed of iron; that the action of the shaft of the screw would prevent wooden vessels from lasting through a succession of long voyages without very considerable repairs from the vibration in the after body; and that the wood, by frequent concussion and constant working, would gradually lose its power of resistance, the fibres becoming bruised and compressed, which would not be the case with an iron ship, at least to anything like the same extent. Indeed, the naval constructors ought frankly to have told their Lordships that it would be unsafe to send a wooden ship to sea fitted with a very powerful propeller. No stern framework could be built to resist the vibration of the largest class of engines now in use in the navy. An iron ship, moreover, affords a much better and more solid foundation for the engines.
[126] Dr. Lardner (“Steam-engine,” p. 479) observes that, “when first introduced by Mr. Galloway, each board was divided into six or seven parts; this was subsequently reduced, and in the more recent wheels of this form constructed for the Government vessels, the paddle-boards consist only of two parts coming as near the common wheel as is possible, without altogether abandoning the principle of the split-paddle.”