Perhaps electricity, which has already achieved so many marvels, is destined to take a still more prominent part as a motive-power in the working of ordinary railways, and may help out of the difficulty by inaugurating still higher speeds without the necessity of incurring stronger works or heavier permanent way. In addition to its success in the telegraph, in the telephone, and in its brilliant light, electricity is every day coming more and more to the front as a motive-power. At present many tramways and short lines, some of them in tunnel, some above ground, and many of them with very steep gradients, are successfully worked by electricity; but these, being of modern construction, were specially designed and equipped for that method of working, and none of them as yet resort to high speeds. Such rapid strides have, however, been already made in the progress of this system of haulage, as to promise that both increased power and speed will be forthcoming when the demand for them is made manifest. Various modes of application are being tried: overhead wires, underground wires, conductors on the level with the rails, storage batteries or accumulators, and self-contained electric motors, each and all of them being carefully tested to ascertain the comparative cost and efficiency. Much will depend upon the localities and advantages to be obtained for the respective generating stations. In places where a large, constant, and unutilized water supply is available, a great saving may be effected in the most expensive item of electric working, but in the greater number of cases steam-power will have to be adopted for driving the generating machinery. The main question will be whether electricity in its most approved form of application can haul a ton of paying load for one mile at a less average cost, and at as great or greater speed than the ordinary locomotive. Until there is 356 very clear evidence that electricity is cheaper, there will not be any great inducement for its general use as a motive-power on ordinary railways. Experiments have been made on some existing railways to ascertain how far this new motive-power can be made serviceable under special circumstances. In one case, a powerful electric motor-car has been introduced for working frequent and heavy trains through a long tunnel, where the atmosphere with ordinary steam locomotives became foul almost to suffocation, and the result has shown that the traffic can be hauled efficiently by electricity, and the air in the tunnel maintained pure and clear. In this instance, the question of cost was of secondary importance, the primary object being to avoid the asphyxiating gases emitted from the ordinary locomotives.