5IO 



NATURE 



[September 24, 189: 



have now taken up the subject, and are making an oil engine ; 

 whilst the big agricultural engineering firm, Hornsby s, of 

 Grantham, have also turned their attention in this direction. 

 There have also been efforts made by foreign engineers. A 

 petroleum engine works generally on the same principle as a gas 

 engine, but the chief trouble, we believe, hitherto has been to 

 get over the clogging of parts. This supplies the chief feature 

 in the Priestman design, in which there is a spray maker 

 specially designed to get over this trouble, A jet of oil is first 

 broken up by compressed air, and the spray is then further 

 mixed with air, heated by the hot products of combustion. To 

 cleanse the air it is drawn through cotton wool, which naturally 

 has to be renewed from time to time. The proportions of air 

 and oil vapour are arranged to give an explosive charge, and a 

 regular explosion is obtained every cycle by means of an electric 

 spark. The cylinders are water-jacketted. Messrs. Priestman 

 have fitted a pair of their oil engines into a small launch, which 

 is said to have answered well. Whether petroleum used 

 explosively in ain engine afloat will ever oust our tried but very 

 imperfect servant steam — as the gas engine is superseding the 

 steam engine in so many positions ashore — is a very open 

 question. Certainly it is a great temptation to get rid of the 

 heavy and bulky boiler, which takes up so much room in a boat, 

 but much remains to be done before we can arrive at the more 

 logical method of generating heat energy in the place where it 

 has to be used. It may be that that terrible exhaustion of our 

 coal-fields, about which we heard so much at the meeting of the 

 Association, will be indefinitely postponed by the using of 

 petroleum or other hydrocarbon as a source of motive power. 

 But that is another story. 



Mr. Beauchamp Tower described some improvements in de- 

 tail which he has introduced in the design of that beautiful piece 

 of mechanism by which he has secured to us, by means of gyro- 

 scopically-controlled hydraulic gear, a steady platform at sea ; 

 and Prof. A. C. Elliott read a paper on the transmission of 

 power by compressed air. Dr, William Anderson described 

 his revolving water purifier ; and Mr. Faija gave a long account 

 of many points in connection with Portland cement. These 

 were all the papers read on Friday, 



On Saturday there was no meeting in Section G, and Monday 

 was, according to custom, devoted to electrical matters. Mr. 

 W. H. Preece opened the proceedings with a long paper, or 

 rather lecture, ou the London and Paris telephone, in the course 

 of which he was enthusiastic upon the success which had been 

 obtained. He is sanguine that before long we shall be able to 

 talk between London and Berlin. Of course, he improved the 

 occasion by insisting on the necessity of metallic returns, a point 

 upon which all will agree with him except shareholders in tele- 

 phone companies. Naturally, also, Mr. Preece did not fail to 

 hint how much better off the British public would have been had 

 telephone exchange been left in the hands of the Post Office. 

 No doubt, if all the telephones were now transferred to Mr. 

 Preece's guidance, we should sooner have metallic returns, and 

 Christian patience would be less exercised ; but the question may 

 arise whether we should have had any telephones at all now if 

 Government monopoly had not been broken through. With 

 Mr. Preece as the controlling factor, we should answer " Yes." 

 But there are other sorts of Government officials than Mr. 

 Preece. 



Mr. Bennett's paper on the telephoning of great cities referred 

 mostly to the arrangement of details of exchange. 



Prof. G. Forbes read a long paper, in which he gave an 

 account of recent progress in the use of electric motors. It was 

 of an interesting nature, and dealt largely with the advance that 

 has been made in America. We trust Mr. Forbes is better ac- 

 quainted with Transatlantic electrical practice than he is with one 

 branch, at least, of British practice ; for when he said, as we 

 understood him, that there are no electrical cranes in England, 

 he was certainly wide of the mark. 



Papers by Mr. N. Watts, on electric fire-damp indicators, and 

 by J. A. Timmis, on electric lighting in trains, were also on the 

 list. 



On Tuesday, August 25, Section G held its last sitting, and 

 there was a varied selection of papers. The first was a contri- 

 bution by Mr. A. R. Bennett, in which he advocated a system 

 of house-to-house parcels distribution, which would certainly be 

 very convenient if it could be carried out. He proposes tunnels 

 under the street with miniature electric railways. That would 

 be a difficult thing to arrange in any of our cities, the space 

 being so occupied by gas- and water-pipes, sewers, electric 



NO. II 43, VOL. 44] 



wires, hydraulic mains, and many other things, were the tunnels 

 simply to be run straight away with only stations at distant 

 points ; but Mr. Bennett proposes to make this a house-to-house 

 service, each subscriber having his own siding. The tube would 

 be rectangular, with two lines of rails one above the other. By 

 means of semaphores at the central station, worked electrically 

 by the passage of the train, so that the operator can always tell 

 where the train is, and by further electrical connection he is 

 able to shunt the train into the subscriber's own siding. When 

 one subscriber wants to send a parcel to another, he procures a 

 truck, and despatches this through the tunnel to the central 

 station, from whence the operator forwards it to the right 

 address. There is even an arrangement for unloading automa- 

 tically, and the truck can then be brought back by the operator 

 without the intervention of the subscriber. The idea is fasci- 

 nating, and we may say that it appears quite practicable ; but it 

 will not come yet. Some day, when we determine to pull down 

 and rearrange London — as manufacturers throw aside obsolete 

 but perfectly sound machinery to gain the economy of some 

 newer designs — Mr. Bennett's electrical exchange may come in ; 

 and then the blessing it will be to the community will be in- 

 calculable. We can have a five minutes collection and delivery 

 of letters ; butcher-boys will no longer whistle at the side door, 

 and the baker will cease to scribble on the gate-post. 



Mr. W. Worby Beaumont next read a paper on internal and 

 external work of evaporation. This is one of a series of mono- 

 graphs which the author has prepared on this subject, but the 

 matter is too abstruse for us to deal with in this very brief 

 account of the four days' meeting. Were we to attempt to 

 abstract the paper, it might lead us into controversial matter. 



Major R. de Villamil's paper on the action of screw-pro- 

 pellers was a praiseworthy effort to accomplish the apparently 

 hopeless task of lifting the practice of designing the screw- 

 propeller from the region of empiricism — where it has always 

 dwelt — to the domain of pure science. We fear, however, in 

 spite of it, that the marine engineer will still adhere to the 

 ancient rule-of-thumb by which alone he is now guided. It is 

 curious that the man who has done most to improve the design 

 of the screw-propeller was essentially non-scientific. He made 

 his chief discovery in an endeavour to do one thing, but pro- 

 duced the reverse result. When Griffith first used the spherical 

 boss, he was trying to produce a retarding effect, but found, on 

 trial, that he had added greatly to the efficiency of the screw. 



Mr. Beaumont also read a paper on the screw-propeller. He 

 described a method of reversing the direction of thrust by means 

 of feathering-blades, on the well-known Bevis principle. The 

 advantages claimed were that, as the engines and screw would 

 be always running in one direction, there would be no momentum 

 of moving parts to be overcome when it was desired to go from 

 ahead to astern, or vice versd, and therefore there would be less 

 danger of breakage of the mechanism. The proposal was some- 

 what roughly handled in the discussion which followed, but we 

 think that Mr. Beaumont fairly held his own in his reply. The 

 most valid objection appeared to be that of Mr. Heard, who 

 pointed out that the pressure on a given area of the blade was 

 by no means constant throughout each revolution, and the dis- 

 turbance would cause the joints of the mechanism to wear. 

 For this reason there would be introduced an undesirable and 

 even dangerous play on the pins after the apparatus had been in 

 use some time. 



A paper upon non-conducting coverings for steam-boilers 

 having been read, the business of Section G was brought to a 

 close with the usual votes of thanks. 



ANTHROPOLOGY AT THE BRITISH 

 ASSOCIATION. 

 'X'HE proceedings began with the President's address, after 

 -'■ which Prof. R. K. Douglas read a paper on the social and 

 religious ideas of the Chinese as illustrated in the ideographic 

 characters of the language. After a short introduction, showing 

 that the Chinese ideographic characters are picture-writings, the 

 author gave an account of the earliest or hieroglyphic form of 

 the writing, the development of this resulting in the ideographic 

 characters. The social habits of the people and their domestic 

 life were illustrated by a number of ideograms descriptive of 

 their household arrangements and relationships. The author 

 traced in the written characters the ideas associated with men 

 and women, their virtues and their failings ; the notions connected 



