Part II. 1860. In this interesting paper, Mr. Evans calls attention to

one or two important facts, certainly not known to the general public, or perhaps not even to many shipbuilders. He says, p. 354: “In an iron sailing-ship, built head to south, there will be an attraction of the north point of the compass to the head, and if built head to north, a like attraction to the ship’s stern; and so far there would seem to be no advantage in one direction over the other. But, in the first case, the topsides near the compass have weak magnetism; in the second case, they are strongly magnetic: the first position seems therefore preferable. “In an iron steam-ship, built head to the south, the attraction due to machinery is added to that of the hull, whereas in one built head to the north, the attractive forces of hull and machinery are, in the northern hemisphere, antagonistic, and a position of small, or no ‘semicircular’ deviation for the compass may generally be obtained. To iron steam-vessels engaged on the home or foreign trades in the northern hemisphere, this direction of build is therefore to be preferred.” And, again, at p. 355, he remarks: “As every piece of iron not composing a part of, and hammered in the fabrication of the hull,—such as the rudder, funnel, boilers, and machinery, tanks, cooking galleys, fastenings of deck houses, &c.,—are all of a magnetic character differing from the hull of a ship, their proximity should be avoided, and, so far as possible, the compass should be placed so that they may act as correctors of the general magnetism of the hull. “A compass placed out of the middle line of the deck is affected by the nearest topside, and its deviations must necessarily be much increased if that topside has the dominant polarity, as in ships built east or west.” [119] “The principal reason of an iron vessel being so much healthier is on account of her coolness and her freedom from all manner of smell; in an iron vessel there is no disagreeable smell of bilgewater, which there is in a wooden vessel in a tropical climate; it is, in fact, the difference between carrying water in a cask, and in a tank.” (Evidence of Mr. McGregor Laird, p. 58, “Steam Navigation to India.”) [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 300,000_l._ (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.” [127] April 14th, 1858. [128] See Tredgold “On the Steam-engine;” Appendix D, 1842, p. 292; Woodcroft’s MS. Collection, p. 22; Bourne “On the Screw-propeller,” p. 8, and other writers. [129] Woodcroft’s “Specifications,” p. 1, n., pp. 25 and 28. Ibid., pp. 31 and 34. [130] It would appear that his experiment was successful if reliance can be placed, as I have no reason to doubt, on the accuracy of a letter from Mr. Fulton, in the memoir by E. Cartwright, London, 1843, p. 142. [131] Woodcroft “On Steam Navigation,” p. 54; with drawing; Bourne “On the Screw-Propeller,” p. 12; and accounts of trials which appeared in the newspapers, 1802. [132] Woodcroft “On Steam Navigation.” [133] As one more conspicuous than any other, it must be stated that, in March 1832, Mr. Bennet Woodcroft patented an “increasing screw-propeller,” which he thus describes: “A spiral worm blade or screw coiled round a shaft (this resembles the invention of Watt) or cylinder of any convenient length and diameter, in such form that the angle of inclination which the worm makes with the axis of the cylinder continually increases, and the pitch or distance between the coils or revolutions of the spiral, continually increases throughout the whole length of the shaft or cylinder upon which the spiral is formed.” (Specifications of “Marine Propulsion,” Part II. p. 112.) [134] The number of claimants to every important invention is remarkable. An impartial student will, however, probably come to the conclusion that the invention of the screw and its application was, like that of the steam-engine itself, the sole property of no one man, as he finds by research that experiments to discover the means of applying the screw as a motive power to ships were at different periods spontaneously and independently made in various places by inquiring minds, who frequently were perfect strangers to each other and to each other’s discoveries or appliances; yet, as time passes on, and the labours of others are forgotten, a nation or a town claims for some one of its countrymen or townsmen who may have experimentalised on an invention which has become of great use to mankind, the sole or the largest share of the credit of the invention, and erects in their midst an enduring monument of his fame. Such would appear to be the case of Frédéric Sauvage, who has just (October, 1874) had a statue erected to his memory in the town of Boulogne-sur-Mer, where he was born on the 20th of September, 1786. On either side of the monument (which is 14 feet high surmounted by a large bronze bust of M. Sauvage) is an inscription setting forth the date of his birth and of the translation of his remains, together with a list of his inventions. On the front are the two words “Frédéric Sauvage,” and a bronze bas-relief showing a vessel with a screw-propeller. Frédéric Sauvage’s life was similar to those of many other inventors, in that he spent his days and fortune in perfecting inventions which brought him no profit. Having lost his own money, he borrowed from others, and, being unable to repay, was thrown into a debtors’ prison, which he afterwards exchanged for a madhouse, where he died on the 19th of July, 1857. [135] “The Screw-Propeller: who Invented it?” by Robert Wilson, published by Thomas Murray and Son, Glasgow, 1860. [136] See “Specifications relating to Marine Propulsion,” Part II. pp. 127 and 128; _London Journal_ (Newton’s), p. 14, conjoined series, p. 34; _Mechanics’ Magazine_, vol. xxvii. p. 130, vol. xxviii. p. 215, vol. xxix. pp. 143 and 283, and vol. xlii. p. 225; _Artizan_, vol. viii. pp. 187 and 209; also Bourne “On the Screw-Propeller,” pp. 30 and 34. [137] See Weale’s Papers on “Engineering,” vol. iii. Part V. pp. 1-7, “Steam Navigation.” [138] With regard to the question of the progress of steam-ships in the Royal Navy since then, Mr. T. H. Farrer, of the Board of Trade, remarks, with great force, in a letter I recently received from him: “We hardly know how fast we move. One of my first colleagues at the Board of Trade, in 1850, was Admiral Beechey, an officer of very superior attainments and intelligence, and one who, having been much employed on surveys, was well acquainted with steam-vessels. And yet I well remember his telling me that he did not believe that the Navy of the future—the Royal Navy—ever could consist of steamers! Nor could he endure iron ships. It was a very few years after this that, in company with him, I witnessed one of the most beautiful sights of my life—the Naval Review at Spithead, in the first summer of the Russian war, when the last four or more sailing-vessels of the Royal Navy formed the attacking squadron. I shall never forget the beauty of the scene, when late in the afternoon these magnificent ships came on with a gentle breeze from the east, and the descending sun shed a ‘dying glory’ on their towers of canvas. It was a fit obsequy for the Hearts of Oak of Rodney, Howe, and Nelson.” [139] “Specifications relating to Marine Propulsion,” Part II. p. 127. [140] _Mechanics’ Magazine_, vol. xxxi. p. 225. [141] The first experimental trip of the _Archimedes_ was made on Monday, October 14th, 1839, the second on the following Wednesday, in the presence of Sir Edward Parry, Sir William Symonds, Captains Basil Hall, Austin, and Smith, R.N., and several civil engineers. Subsequently to the Admiralty trials between Dover and Calais, Captain Chappell, R.N., sailed round England and Scotland in her, calling at numerous ports; details of this voyage will be found in Appendix D to Tredgold “On the Steam Engine.” [142] The _Rattler_ was launched from Sheerness Dockyard in April