Page:Popular Science Monthly Volume 60.djvu/434

426 though in Mond gas Parliament sanctioned a novel and rival method of power transmission. While its use for lighting, for electrolytic manufactures, etc., steadily advanced, it was in regard to its applications to traction that electricity was most conspicuous. Some schemes of this sort were brought into actual operation, some were definitely decided upon; but more still were mere suggestions, few of which have much chance of being translated into fact. Among the last class must be ranked the host of tube-railways which threaten to invade London. If Parliament were to sanction all those proposed and if (what is not less unlikely) their promoters were to obtain the money for their construction, it seems that in some places the subsoil of the City of London would be transformed into a solid mass of iron tubes, and it is doubtful whether there would even be room for all in the earth, whatever the ingenuity of drawing-offices may do in plans. This activity on the part of promoters is largely a result of the success of the Central London Railway, but it is conveniently forgotten that there are other tube railways which cannot point to anything like similar results. In the near future, too, it does not seem improbable that there may be a change in popular sentiment in favor of shallow lines just below the surface, where efficient ventilation will be obtainable; for people are discovering that steam and sulphur are not the only things that make an atmosphere offensive, and they may soon realize that to roll a mass of used-up air forwards and backwards in a narrow tunnel, without ever renewing it, does not constitute ventilation sufficient either for comfort or for health. During the year many towns brought electric traction into operation on their surface tramlines, and after protracted obstruction the authorities of Kew Observatory, who feared that certain magnetic observations carried on at that somewhat unsuitable site would be injuriously affected by stray electric currents, agreed to withdraw their opposition to the opening of the first electric tramway seen in London, in consideration of the company which owns the lines contributing £10,000 towards the expenses of moving the instruments. Among proposals which were definitely determined upon may be mentioned the adoption of electrical propulsion for the Mersey Railway in Liverpool, and for the Metropolitan and District Railways in London, both to a large extent with the aid of American capital. For the latter, two systems were considered—the Ganz polyphase and the ordinary direct current. The question which should be selected was referred to the Board of Trade for decision, and as soon as that step was taken the matter was practically settled, for few could doubt but that so eminently conservative a body would choose a system which has been well tried in various parts of the world, in preference to one which has scarcely passed the experimental stage, and which, moreover, involves the employment of electricity at a much higher pressure than it is used to. In another case also the