May 22, 1919] 



NATURE 



233 



claims made for the equipment of the American battle- 

 cruisers. They are designed for a speed of thirty-five 

 knots, and require 180,000 h.p. to be delivered to four 

 propellers running at 250 revolutions per minute. Sup- 

 posing that one motor out of the eight breaks down, it 

 can be instantly disconnected, and tlie loss in total 

 power being only one-eighth, the speed would only be 

 reduced by about one knot. For cruising speeds the 

 ship will attain twenty-six knots with only two 

 generating sets and four motors at work, and nineteen 

 knots with one generating set only and four motors in 

 use. At full power the efficiency claimed is 93 per 

 cent. On the other hand, it was pointed out that the 

 electric gear was considerably heavier than the 

 mechanical gear, and its efficiency is about 2 per 

 cent, lower. The author considers that there were 

 spheres of usefulness for both the "geared turbine" 

 and the " turbo-electric system," and that in some cases 

 they might with advantage be used in combination. 



Sir Dugald Clerk read a paper on "The Distribu- 

 tion of Heat, Light, and Motive Power by Gas and 

 Electricity " to the Royal Society of Arts on March 19. 

 He takes as his basis of comparison for heating the 

 amount of fuel consumed per thermal unit available in 

 the gas or electricity, for lighting the amount of fuel 

 consumed per candle-hour, and for motive power the 

 horse-power-hours available per pound of fuel. From 

 the point of view of coal conservation, he concludes 

 that gas-heating should be used. Judging on this 

 basis, there is little to choose between gas and electric 

 lighting, but he is strongly in favour of gas motive 

 power. Sir Dugald Clerk points out that of the 

 coal-gas consumed in the United Kingdom probably 

 55 per cent, is used for heating, 35 per cent, for 

 lighting, and 10 per cent, for motive power. He cal- 

 culates that if electricity were used for these pur- 

 poses 92 per cent, more heat units would be con- 

 sumed. He concludes that, even assuming that the 

 success of the super-electric stations so much dis- 

 cussed at present were assured, yet a gas service from 

 a coal conservation point of view would be twice as 

 economical. As regards thermal efficiency, this may 

 be taken as correct, but it is unduly disparaging to 

 the super-electric stations. The establishment of these 

 stations would undoubtedly effect immense economies 

 by abolishing many of the present wasteful electrical 

 stations. Electricity was ver\' largely used for driving 

 the machinery upon which the winning of the war 

 depended. It is difficult to believe that gas-engines 

 would have been so successful. The rapidly extending 

 use of electricity for cooking proves that more items 

 than the thermal efficiency have to be taken into 

 account before a just comparison can be made. 



Sir Robert H.adfield has sent us a translation of 

 a recent statement by M. Honor^ giving some account 

 of the French Steel and Iron Masters' Association. 

 It appears from this that in recent years French ferro- 

 metallurgy has shown a pronounced tendency towards 

 concentration of effort. From 383 in 1875 ^^"6 number 

 of works dropped to 208 in 1912, while the total iron 

 and steel production increased from 900,000 to 

 4,900,000 tons. Whereas, therefore, the capacity of 

 the works averaged 2350 tons in 1875. it ^ad been 

 raised to 21,700 tons in 1912. As the works grew 

 fewer in number, but individually stronger, they were 

 led, by reasons of transport, supplies, etc., to group 

 themselves in regions favourable to production. In 

 1875 pig-iron was manufactured in fiftv-seven depart- 

 ments; in 1912 four-fifths of the pig-iron and three- 

 fourths of the steel production had been concentrated 

 in two departments, Meurthe-et-Moselle and Nord. The 

 Steel and Iron Masters' Association dates from 1864. 

 After twenty years it became the Emplovers;* Fodera- 



NO. 2586, VOL. 103] 



tion of Iron Masters, the exclusive object of which 

 was the study and defence of the economic, industrial, 

 and commercial interests of the ferro-metallurgical 

 industry. In 1914 the association numbered 252 ad- 

 herents, representing 97 per cent, of the French pro- 

 duction of pig-iron and 93 per cent, of steel. The 

 total capital involved was 1150 million francs, and the 

 number of workmen employed about 200,000, who in 

 1912 received 400,000,000 francs. 



In a lecture on "The Sudd Reservoir," delivered 

 at a meeting of the Institute of Egypt at 

 Cairo on February 17, Sir William Willcocks 

 reaffirms the claim that the problem of reser- 

 voir storage in the Nile Valley for irrigation 

 purposes has been solved by Mr. John Wells ".nd 

 himself in their report on the sudd region o* 

 the White Nile. In support of his contention he ad- 

 duces certain figures to show that, under the con 

 ditions prevailing in the Lower Nile, there is a shortage 

 of 6 milliards of cubic metres of water out of the 

 13^ milliards required annually for cultivation pur- 

 poses in Egypt. This is after deducting 2 milliards 

 as the capacity of the Aswan Reservoir as it stands. 

 Sir William estimates that the 6 milliards deficiency 

 can be made good from the natural storage supplies 

 in the sudd region at a cost of about 6,ooo,oooi.(E.). 

 He also advocates the entire reconstruction of the As- 

 wan Dam at a cost of 3,000, oooZ.(E.), on the groun-l 

 that the present dam is not high enough and pos- 

 sesses "serious defects and shortcomings." The sudd 

 region has, of course, long been regarded as an 

 unfortunate blemish on the White Nile, both as re- 

 gards navigation and drainage. It is covered with 

 a dense mass of decayed vegetation, papyrus roots, 

 reeds, and grasses, resembling p>eat almost in its con- 

 sistency, and offering an obstruction which on more 

 than one occasion has had to be cut through for 

 something like fifty miles in order to obtain a pas- 

 sage for boats. Sir William characterises it as one 

 of the most wonderful reservoirs in the world. " A 

 score of milliards of cubic metres of water stand welt 

 above the level of the flat plain as though they were 

 congealed. It is a veritable glacier at the head of the 

 White Nile, and feeds it as the Himalayan glaciers 

 feed the Ganges." 



One of the most interesting ships added to the 

 Navy during the war was the seaplane-carrying ship 

 Argus, built by Messrs. William Beardmore and Co., 

 Ltd., at Dalmuir. A fully illustrated account of this 

 ship appears in Engineering for March 28. There is 

 absolutely no obstruction on the flying-deck, not even 

 funnels, and there is space under this deck for the 

 accommodation and repair of seaplanes. She is, 

 therefore, a floating hangar, the space given up for 

 this purpose being 330 ft. long, 68 ft. wide overall, 

 and 48 ft. clear, with a clear height of about 20 ft., 

 and is of a capacity regarded as sufficient to accom- 

 modate twenty seaplanes. Hoists are provided from 

 the hangar to the flying-deck, and cranes are avail- 

 able for lifting the seaplanes from the water on to 

 the hangar-deck. The vessel was laid down originally 

 as a first-class passenger and cargo steamer, and the 

 .Admiralty decided in 19 16 to have her completed as 

 a seaplane carrier. The navigating bridge, bridge- 

 houses, wireless offices, etc., are placed forward under 

 the flving-deck. The chart-house is capable of being 

 raised above the flying-deck level or lowered to a 

 stowing position under the flying-deck by hydraulic 

 power, and when in a raised position commands a 

 clear all-round view. 



Mr. F. Edwards, 83 High Street. Marylebone, 

 W.I, has just issued a Catalogue (No. 389) of upwards 

 nf nine hundrnd now nnd second-hand works dealing 



