of such a pressure being regulated by a valve, an example of which is shown at Fig. 1, and provided with the tappet levers, i i, hinged to the valve chest, C, as shown, and attached to spindles, i' i', operating the slide valves, and struck alternately at the end of each stroke, thus operating the valves and the guillotine connections, i² and i³. The front ends of the cylinders may be placed at an angle for the more convenient delivery of the moulded articles.--_Iron_. [Illustration: MACHINE FOR MAKING ELECTRIC LIGHT CARBONS] * * * * * NEW ELECTRIC BATTERY LIGHTS. There has lately been held, at No. 31 Lombard Street, London, a private exhibition of the Holmes and Burke primary galvanic battery. The chief object of the display was to demonstrate its suitability for the lighting of railway trains, but at the same time means were provided to show it in connection with ordinary domestic illumination, as it is evident that a battery will serve equally as well for the latter as for the former purpose. Already the great Northern express leaving London at 5:30 P.M. is lighted by this means, and satisfactory experiments have been made upon the South-western line, while the inventors give a long list of other companies to which experimental plant is to be supplied. The battery shown, in Lombard Street consisted of fifteen cells arranged in three boxes of five cells each. Each box measured about 18 in. by 12 in. by 10 in., and weighed from 75 lb. to 100 lb. The electromotive force of each cell was 1.8 volts and its internal resistance from 1/40 to 1/50 of an ohm, consequently the battery exhibited had, under the must favorable circumstances, a difference of potential of 27 volts at its poles, and a resistance of 0.3 ohm. When connected to a group of ten Swan lamps of five candle power, requiring a difference of potential of 20 volts, it raised them to vivid incandescence, considerably above their nominal capacity, but it failed to supply eighteen lamps of the same kind satisfactorily, showing that its working capacity lay somewhere between the two. A more powerful lamp is used in the railway carriages, but as there was only one erected it was impossible to judge of the number that a battery of the size shown would feed. _Engineering_ says the trial, however, demonstrated that great quantities of current were being continuously evolved, and if, as we understood, the production can be maintained constant for about twenty-four hours without attention, the new battery marks a distinct step in this kind of electric lighting. Of the construction of the battery we unfortunately can say but little, as the patents are not yet completed, but we may state that the solid elements are zinc and carbon, and that the novelty lies in the liquid, and in the ingenious arrangement for supplying and withdrawing it.