Since 1877 the subject of utilizing the re-cently discovered powers of electricity as an illuminating agent, has occupied the attention and employed the skillftu manipula tion of leading inventors and other scientists. M. Jablochkofl, an eminent Russian, has received the credit of first producing a very much simplified form of lamp, in which, without using mechanical contrivances in the nature of clock-work, it is entirely possible to manage a number of lights, so far separate in their action that the going out of one of the lamps will not cause the rest to become extinct. This particular kind of lamp or candle, as it is sometimes termed, is produced by two rods of gas carbon, kept side by side by an asbestos holder, but slightly separated by a slight rod of some insulator, as glass or krolin. Copper tubes hold the carbons, and connected copper wires lead the current from the dynamo-electric machine used to produce the power. The ingenious and delicate mechanism would require plans to give a non-scientist a proper idea of the operation. Edison and other eminent electricians have patents covering the same results by many different methods. Many public buildings, including that vast edifice, the New York Post-Office, and a number of streets and private buildings in New York City, are brilliantly illuminated by this process. It has been found in practice admirably fitted for the illumination of the lofty lanterns of light-houses, and for the flashing of signals to and from forts and other beleaguered places. It has also the valuable property of being used to light up the depths of the sea. (See page 793).