July 13, 1911] 



NATURE 



57 



coincided with the abandonment of the paddle-wheel in 

 favour of the screw-propeller. The warship fitted with the 

 most powerful machinery in i860 was the Warrior, which 

 had engines of 5409 indicated horse-power. The introduc- 

 tion of surface condensers was referred to, as also triple- 

 expansion engines, the evaporator, and the steam turbine. 

 The author also dealt with the troubles experienced in 

 finding suitable boilers. 



Mr. C. E. Ellis described the advances made in the 

 manufacture of armour for ships during the last fifty 

 years. To resist the attacks of guns of ever-increasing 

 power, the thickness of side armour was increased from 

 55 inches in the case of the Agincourt (1S6S) to 24 inches 

 in the Inflexible (1881). The introduction of compound 

 armour effected a revolution in ship protection. Its partial 

 adoption for the turret protection of the Inflexible effected 

 a saving of 600 tons in weight. Since then the efforts of 

 Krupp, Captain Tresidder, and Harvey have led to great 

 reduction in the weight of armour required. In evidence 

 of this, a 12-inch plate, tested in 1S97, was attacked by 

 three armour-piercing projectiles of high quality. In each 

 case the projectile was completely broken up, and no 

 cracks appeared in the plate. 



Dr. S. J. P. Thearle traced the developments in mercan- 

 tile ship construction. Fifty years ago some of the ships 

 of the mercantile marine were being built of iron, some 

 ol wood, and a small proportion were of composite con- 

 struction. In i860 the length of an average cargo steamer 

 was less than 200 feet ; now it has reached to 350 and 

 400 feet. Much of the development has been owing to 

 the introduction of mild steel for iron. Finality has not 

 yet been reached, nor is it likely to be in the near future. 



It is of interest to note from the Hon. C. A. Parsons' 

 paper, on the marine steam turbine, that there are now 

 a total of 2S1 war vessels, 87 mercantile vessels, and 10 

 yachts fitted with his well-known turbines. The total 

 horse-power of these amounts to 5,841,000. 



An account of the progress of naval construction in 

 Japan was given by Rear-Admiral Motoki Kondo. At 

 present there are four navy yards in Japan, and two large 

 private shipbuilding yards, capable of turning out the 

 heaviest warships complete with their machinery. Armour 

 plates of trustworthy quality are now being produced in 

 the Kure Navy Yard. The author understands that the 

 process is a special one invented by Japanese engineers, 

 and that the results are fully up to the best armour plate 

 of the day. The progress of naval engineering in Japan 

 was described by Engineer-Rear-Admiral Terugoro Fujii, 

 and the development of merchant shipbuilding in the same 

 country by Dr. S. Terano and Mr. M. Yukawa. These 

 acknowledged the debt which Japan owes to engineers in 

 this country for advice and help. 



A paper on the design and service performance of the 

 Transpacific liners Tenyo Mara and Chiago Maru was 

 presented by Prof. S. Terano and Prof. Baron C. Shiba. 

 These vessels were built in Japan ; they are the largest 

 vessels yet produced in the East, and are the first turbine 

 steamers in Pacific waters. During the last year, and 

 owing to the uncertainty of oil-fuel supply in Japan and 

 China, the owners decided to burn coal. Six of the boilers 

 were converted to use coal, and the remaining seven still 

 burn oil. It is found that the consumption of coal is 20 

 to 22 tons as against 14 tons of fuel oil. 



Among the many other papers presented is one by Prof. 

 A. C. E. Rateau, on the rational application of turbines 

 to the propulsion of warships. Owing to the low efficiency 

 at ordinary speeds, turbine machinery reduces by one half 

 the radius of action. This does not have much import- 

 ance to Great Britain, as she has naval bases in all the 

 seas of the world ; but other nations are not in the same 

 position as regards turbines ; indeed, one of the most 

 powerful of these is about to replace turbines by recipro- 

 cating engines for her new battleships. The author 

 describes a combination of reciprocating engines and 

 turbines, introduced into the French Navy in 1906, which 

 appears to meet the rase. The destroyer Voltigeur, fitted 

 with this svstem, shows consumptions, at speeds below 

 20 knots, slightly above those obtained in destroyers fitted 

 with reciprocating engines. Above 20 knots the consump- 

 tions remain fewer than those of all other destroyers, even 

 with turbines only. 



NO. 2176, VOL. 8/] 



On Wednesday, July 5, a large company proceeded to 

 the National Physical Laboratory for the opening of the 

 experimental tank. An account of the opening is given 

 in another article in this issue. 



THE OPENING OF THE NA TIONAL EXPERI- 

 MENTAL TANK AT THE NATIONAL 

 PH 1 'SIC A L LA Ih >RA TOR \ '. 



'FI1E National Experimental Tank for experiments on 

 ^ models of ships, recently completed at Teddington, 

 was formally opened on Wednesday, July 5, and the great 

 public interest taken in the work was evidenced by the 

 number of distinguished guests who travelled to Tedding- 

 ton to be present at the ceremony. The chair was taken 

 by Sir Archibald Geikie, who, as president of the Royal 

 Society, is chairman of the general board of the labora- 

 tory, and he was supported by Lord Rayleigh, the chair- 

 man of the executive committee, with Lady Rayleigh, the 

 Marquis of Bristol, president of the Institution of Naval 

 Architects, and Lady Bristol ; while among those occupy- 

 ing seats on the platform were Mr. A. F. Yarrow, Dr. 

 Glazebrook, the director of the laboratory, and Mrs. Glaze- 

 brook, Sir Wm. and Lady White, Mr. G. S. Baker, the 

 superintendent of the tank, and Mrs. Baker, H. E. Senoi 

 Edwards, Sir Wm. Crookes, Mr. R. W. Dana, Rear 

 Admiral Capps, Herr Hullmann, M. Bertin, Sir Norman 

 Lockyer, Mr. Alex. Siemens, Sir J. W. Swan, Rear 

 Admiral Moore, Mr. A. B. Kempe, Sir J. Rose Brad- 

 ford, Sir J. Larmor, Sir Chas. Parsons, Prof. Unwin, 

 Sir J. Wolfe Barry, Sir David Gill, and Mr. F. W. Black. 



Sir Archibald Geikie, in opening the proceedings, re- 

 ferred to the efforts which had been made since 1901 by 

 the Institution of Naval Architects to secure the funds 

 necessary for the construction at the National Physical 

 Laboratory of a tank for ship-model experiments of a 

 national character, where facilities could be provided for 

 experimental work necessary to shipbuilders to enable 

 them to improve and perfect the principal features in the 

 design of their vessels. The project has now been 

 realised owing to the generosity and enthusiasm of Mr. 

 A. V. Yarrow, who has provided the sum of 20,000!. for 

 the construction and equipment of the tank, while the 

 Institution of Naval Architects has secured guarantees 

 amounting to 1340/. per annum towards the sum of 2000I. 

 per annum for ten years considered necessary to ensure 

 the successful working of the tank. 



Lord Rayleigh, to "whom fell the task of declaring the 

 tank open, spoke of the pioneer work accomplished by 

 the late Mr. William Froude, who in 1871 started a tank 

 at Torquay, and by his investigations established the 

 fundamental principles to be followed in the application of 

 this method of research to the science of shipbuilding. 

 The Torquay tank was followed by the Admiralty tank at 

 Haslar, where the work so well begun by the father is 

 now ably continued by his son, Mr. R. E. Froude. _ Other 

 tanks are now in existence in shipbuilding yards in this 

 country, as well as on the Continent and in the United 

 States of America. At the request of the Institution of 

 Naval Architects, Dr. Glazebrook has visited a number of 

 these tanks, and every assistance has been _ cordially 

 rendered him, in particular by M. Bertin in Paris and by 

 Prof. Busley and Herr Gebers in Germany, in the effort 

 to ensure that the new national tank, for which the 

 laboratory and the nation are indebted to Mr. Yarrow, 

 shall be thoroughly well equipped for its work. To the 

 realisation of the scheme the architect, Mr. Mott, and the 

 contractors, Messrs. Dick Kerr and Co., have also largely 

 contributed, while the superintendent of the tank, Mr. 

 Baker, and his assistants have worked hard to ensure that 

 the details of the equipment should be in every way satis- 

 factory. 



In his further remarks Lord Rayleigh made reference to 

 some of the more important of the principles established 

 bv Mr. Froude, and especially to the principle of dynamical 

 similarity, which laid down the conditions and relation-; 

 governing the application of " model " methods to problems 

 of naval architecture, as well as to similar problems in 

 aeronautics and other subjects. In illustration of this 



