Page:The Working and Management of an English Railway.djvu/170

 only in a transitional or experimental stage, have not yet seen their way to adopt the system to any large extent, a brief account of what has been done may perhaps be of interest.

It is tolerably well known that there are at least three methods in which a current of electricity may be obtained for lighting the carriages of a train. A primary battery may be used, or secondary batteries as on the Brighton line, or the dynamo may be used direct. Each system has its own supporters, but the greatest consensus of opinion, at any rate amongst railway engineers, appears to be in favour of either the secondary batteries, or the direct action of the dynamo, while possibly the ultimate solution will be found in a combination of the two; that is to say, the train will carry both a dynamo and accumulators; but whether the dynamo is to be carried on the engine or driven from the engine direct, or is to be driven by a separate engine, or by the axle of the guard's van, are points not yet determined with any degree of authority. The train already referred to on the Liverpool and Manchester Railway, carries a Brotherwood's engine and a Siemen's compound shunt dynamo fixed on the tender of the locomotive, with an ammeter and switch on the engine, so that the driver may regulate the current, and there are two lamps in each compartment of the train with an automatic switch arrangement, so that in the event of one lamp failing, the second would be automatically brought into use. The system, which has been devised by the Company's chief telegraph superintendent, does not admit of the engine leaving the train without disconnecting the current, but this difficulty might be overcome by the use of secondary batteries or