ii6 



NA TURE 



[June 3, 1897 



Section II. there were also two subjects introduced, the first re- 

 lating to concrete in marine works, and the second in relation to 

 approaches of docks. Sections III. and VII. sat conjointly, 

 the former of these two dealing with machinery, and the second 

 with applications of electricity. Messrs. Preece, Ellington 

 and Dr. Hopkinson contributed the notes which opened the 

 discussion ; the combined subject for the day being the trans- 

 mission of power by electricity, by water, and by other agents. 

 Mr. Ellington naturally claimed that water was superior to 

 electricity, a statement which was equally naturally disputed by 

 the electricians present. It is needless to say nothing definite 

 was settled on this many-sided question. Perhaps the most 

 interesting contribution to the discussion was that supplied by 

 Prof. Forbes, who had come to the conclusion that the distance 

 over which power might be profitably transmitted by electricity 

 was not far short of looo miles. He had been consulted as to 

 the transmission of power from the Victoria Falls on the 

 Zambesi to the gold mines in Matabeleland and the Transvaal. 

 At first he considered the suggestion altogether impracticable ; 

 but on putting together figures with a view to prove its absurdity, 

 some ideas had occurred to him which led him to believe that 

 the scheme was not so chimerical after all. The electrical world 

 will look forward with interest to the development of Prof. 

 Forbes' plans. 



The proceedings in Section IV., which deal with mining and 

 metallurgy, were of a very practical nature. The most interest- 

 ing of the contributions was that by Mr. Bennett H. Brough, 

 in which he gave some interesting particulars of deep mines in 

 the United Kingdom. At Pendleton Colliery, near Manchester, 

 the workings were 3474' feet below the surface, that being the 

 deepest working in Great Britain. The deepest metal mine in 

 the United Kingdom is the Dolcoath Tin Mine in Cornwall, 

 which is 2582 feet deep. These figures are, of course, exceeded 

 in mines abroad ; a shaft in the copper mines of the Lake 

 Superior district, the deepest in the world, going down to 4900 

 feet. 



Section V. was devoted to shipbuilding. The proceedings 

 were opened by a very instructive note by Mr. Archibald Denny, 

 of Dumbarton, in which he dealt with the practical application 

 of model experiments in merchant ship design. As is well 

 known, Mr. Denny's firm have the only experimental tank of a 

 private nature in the world, it being modelled after the design of 

 the late Mr. Froude. Mr. Denny gave a description of the 

 method of procedure in carrying out these model experiments. 

 A very good discussion followed the reading of this paper, in 

 which Mr. R. E. Froude, Sir Edward Reed, Mr. Thornycroft, 

 Prof. Biles, Sir William White, and others took part. Section 

 VI. was devoted to waterworks, sewerage, and gas works. On 

 the first day of the meeting the proceedings were devoted to a 

 consideration of the law of allocation of underground water. 



On the second day of the conference, Wednesday, May 26, 

 in Section I. (the railway section), the discussions turned chiefly 

 on the economics of light railways. In Section III. the most 

 interesting paper was that contributed by Mr. Bryan Donkin, on 

 ' ' Important Questions in the Economic Working of Steam 

 Engines and Boilers." The author pointed out that for greater 

 efficiency it was desirable to adopt high pressures up to 250 

 pounds, efficient steam-jacketing, reduction of clearance volumes 

 in surfaces of cylinders, and a high number of revolutions. He 

 pointed out that moderately superheated steam had long been 

 employed on the continent, but was coming into favour here very 

 slowly. Superheating reduces cylinder condensation, but, of 

 course, is attended by practical difficulties, and requires more 

 highly-skilled attendance. Mr. Donkin also impressed on 

 the meeting the advantage of using entropy diagrams. He 

 stated that multi-cylinder engines, with twenty or thirty 

 expansions, are very economical, but are only admissible 

 where the barrels and covers are thoroughly steam-jacketed, 

 or superheated steam is used. He also advised greater com- 

 pression than is generally used. He advocated the statement 

 of economy in terms of thermal units per I. PI. P. hour, and also 

 in thermal units per break H.P. hour, whether for saturated or 

 superheated steam. In dealing with steam boilers he pointed 

 out the need of analyses of gases to determine the percentage 

 of CO2, CO, and O. He rightly stated that no boiler experi- 

 ments are complete without such gas analyses. Reference was 

 also made to the use of coal finely ground, which, it is said, was 

 being used on the continent. The information is interesting, 

 remembering the great efforts made many years ago to use 

 powdered coal, and the difficulties which led to the failure of 



NO. 1440, VOL. 56] 



the scheme. It would be interesting to know how these diffi- 

 culties had been overcome. This note concluded by an advice 

 that all engine and boiler trials should be tabulated in uniform 

 manner. . It is satisfactory to know that the "subject is likely to 

 be taken up by the Institution. A speech which the President, 

 Mr. Wolfe Barry, made, gives hope that a Committee will be 

 formed to consider and report on this matter, and it is probable 

 some legislation by the Institution will follow. In order, how- 

 ever, to make the Committee complete it should take a wider 

 range than the Institution of Civil Engineers, which, although 

 our premier engineering society, is not the only representative en- 

 gineering body, more especially in regard to mechanical engineer- 

 ing. Petroleum as a steam-engine fuel was the subject introduced by 

 Mr. Aspinall, the Locomotive Superintendent of the Lancashire 

 and Yorkshire Railway. An interesting discussion followed the 

 reading of this note, but it took rather a practical than a 

 scientific turn. There is no doubt that liquid fuel can be used 

 with great convenience on locomotives, and would speedily sup- 

 plant coal if it could be obtained in sufficiently large quantities 

 and at a sufficiently low price. At present it is only now and 

 then that it can be economically used ; still the Great Eastern 

 Railway have a number of liquid-fuel-burning locomotives in 

 fairly constant use on their system. 



The Electrical Section on this day discussed two subjects — 

 namely, "Should generating plant be mounted on springs?" 

 and "Turbines as applied to dynamos." In regard to the 

 former, it may perhaps be said that the gist of the discussion 

 pointed to the fact that when generating plant has been mounted 

 on springs, the results have not been altogether satisfactory ; 

 but, nevertheless, by mechanical improvements and alterations 

 in detail, the system might be sufficiently perfected to enable 

 it to be worked advantageously. The problem of using turbines 

 was introduced by the Hon. C. A. Parsons. The subject is 

 an interesting one, and the author was well able to deal with 

 it had he been allowed, further time. As it was, the note was 

 decidedly meagre, and the discussion disappointing. Perhaps 

 the paper of most interest on this day was that read in the 

 Shipbuilding Section, by Mr. Parsons, in which he gave some 

 particulars of the wonderful steam-turbine-driven boat which 

 he has recently designed and built. The Turbinia, the boat 

 in question, is 100 feet in length, 9 feet wide, and 3 feet draught 

 amidships, having adisplacement of 44^ tons ; she is, therefore, 

 only half the length, and of very greatly less displacement, than 

 the torpedo-boat destroyers, which have been, hitherto, our 

 fastest vessels. With this little boat, however, Mr. Parsons has 

 made a speed of 32I knots ; but he anticipates that when .some 

 alterations have been made in the machinery, still higher speeds 

 will be reached : we believe up to 34 knots. There is a water- 

 tube boiler and chree steam-turbines working on the compound 

 system in series. Each of these turbines has its own propeller 

 shaft, and on each shaft there are three screws threaded in 

 line. The most remarkable part of the machinery is that the 

 propellers make 2200 revolutions per minute, in order that they 

 may be worked direct from the steam-turbines, which must 

 necessarily revolve at a highspeed. The I. H.P. is 2100, and 

 the consumption of feed water per I.H.P. per hour, 14^ lbs. 

 The weight of the main engines is 3 tons 13 cwt., and the total 

 weight of machinery, including water in boiler, &c., 22 tons. 

 Thus nearly 100 H.P. is developed per ton of machinery, and 

 nearly 50 H.P. per ton of displacement of boat ; it need hardly 

 be said that the figures are unprecedented. 



On the last day of the meeting a large number of papers were 

 read ; to these we can only make brief reference. In a dis- 

 cussion on ball and roller bearings, Prof. Goodman gave some 

 interesting details of experiments he had made with a bearing 

 having an 8-inch diameter ball-race of the thrust-block type, which 

 ran at 1600 revolutions. He had tried the system of using four 

 points of contact between the ball and race, which had been 

 advocated by a correspondent to a technical journal, and which 

 was said to give the perfect rolling contact, but had found that 

 the system would not work satisfactorily ; and it was only when 

 he fell back on the more ordinary double-contact system, that he 

 met with success. A paper by Prof. Biles, in the Shipbuilding 

 Section, on "Improved Materials of Construction," led to an 

 interesting discussion, in the course of which a good deal was 

 said about nickel steel, which is certainly the coming material 

 for shipbuilding if the question of price can be satisfactorily 

 settled ; to effisct which further deposits of nickel must be dis- 

 covered and worked economically. In the Harbour and Docks 

 Section, the Hon. R. C. Parsons described an automatic dredg- 



