i H &USCIEHCE m il At tho recent Bradford meeting of tho Ilrltlsh association n paper read by J II C Kershaw dealt with tho com-paratlvo com-paratlvo cost of power produced by steam engines, water turbines and gas engines, with ths result of showing that gas engines have a very promising promis-ing future. The suprcmncy of tho steam cnglno Is now dlsi uted. a the Ualllmoro Hun. On one sldo tho water wa-ter turbine, on tho other the gas engine, en-gine, has become Its rival "During tho past ten years," saja Mr Ker-taw, Ker-taw, "a most remarkable development develop-ment of hydraulic power has been taking place on tho continent of Europe, Eu-rope, In l'rnnco and (lrrmany, and In America nt Nligarn The aggregate amount of power at the present date generated from falling water forms no Inconslderablo portion of the total power utilized In tho manufacturing Industries, nnd two years ago It was estimated by tho author to be between 23C.OO0 and 3f0,000 horso power. On the other hand, gas engineers have been busily engaged In working out the problems presented by Isrge gas englues and by the utilization of tho waste gases of blast furnaces. Oas rnglncs up to CS0 horso power have been built and have worked smoothly and economically" . 1-ocal considerations will often de-cldo de-cldo one's cholco between the three possible sources of power, but n largo waterfall does not always giro tho cheapest power und the nearness of the conl field will not always mske the sleam engine preferable. The most economical source of power can only be determined after an exhaustive exhaust-ive study of comparative cost data. Water, It Is conceded, Is tho chetpest source of power If Its fall can bo utilized util-ized without much capital expenditure, expendi-ture, but If It costs heavily to utllUa It or to transmit the power when obtained, ob-tained, then steam or gas may be cheaper. Some water powers developed devel-oped In Switzerland, It Is observed, I cost more than the other sources of power. The practicability of large gas rnsjnts Is settled, and under some circumstances cir-cumstances they mutt dtsplaco ths turbine and the steam engine. Their use msy unsettle practical calculations calcula-tions "If they do not cost excessively excessive-ly for maintenance and repairs," says the writer, "large gas en-lnes, In conjunction con-junction with coko ovens and blast furnaces, may entirely, alter .the. present" pres-ent" position of affairs, and ths ntw Industries, which at present are being be-ing established In the neighborhood of water power stations may find themselves lu severe competition with similar manufactures carried on In ths coal nnd Iron districts of the older manufacturing countries."