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Show EDISON'S SYSTEM OF ELECTRIC LIGHTING. Concerning the article on the Electric Light in Scribner, by Mr. Edison's mathematician, the editor received this note: Editor Scribner's Monthly. Dear Sir: I have read the paper by Mr. Francis Upton, and it is the first correct and authoritative account of my invention of the Electric Light. Yours Truly, Thomas A. Edison. From the paper referred to we quote the following: Mr. Edison's idea in regard to the electric light was that, in all respects, it should take the place of gas. Following the analogy of water, the inventor conceived of a system which should resemble the Holly water works. As the water is pumped directly into pipes which convey it under pressure to the point where it is to be used, so the electricity is to be forced into the wires and delivered under pressure at its destination. In the case of water, after being used, it flows away by means of a sewer-pipe, and is lost. But it is easy to imagine that the water used in working machinery, for instance, instead of being lost, might be returned to the pumps and used over and over again. With such a system as this, we should have a perfect analogy to the Edison electric lighting system. The electricity, after being distributed under pressure and used, is returned to the central station. As the light results from no consumption of a material, but is mere transmutation of the energy exerted in the pumping process, it is therefore seen that all which is essential to an electric lighting system is the generator (or pump), the two lines of wire, one distributing the electricity, the other bringing it back, and a lamp which transmutes into light the energy carried by the electricity when it passes from one wire to the other, and in which the energy of the pressure expresses itself as the light. In Edison's invention the amount of electricity delivered in the lamp is determined by the size and resistance in the carbon, just as in water the amount of flow is determined by the size of the openings. As a great many small jets of water can be supplied from one pipe, so a great many lamps or small escapes for electricity can be furnished from one wire. As in the case of water, the amount of work done by electricity either as illuminant or motor is dependent quite as much upon pressure from which it escapes as upon the quantity passing through the wires. We might have a system of lamps which would give a certain amount of light form large quantities of electricity escaping under low pressure, or another system which could give an equal amount of light from a small quantity of electricity escaping under high pressure. As in either case the amount of electricity flowing through a wire is in proportion to the size of the wire, it will be readily seen that the application of pressure made by Mr. Edison obviates the main difficulty in the way of subdivision (i.e., in the way of the ??? ??? use of the electric light), namely, the enormous size and cost of conductors. The well known principle of the effect of pressure upon the dynamic power of electricity had never been utilized because the proper lamp was still unknown. This lamp is Mr. Edison's main discovery. In order to utilize this, one of the plans devised by him was to make the flow of electricity intermittent. Enough was allowed to escape in a short time, say one-third, to keep the lamp all the time supplied. It of course would require a large wire to furnish the quantity of electricity needed, yet two-thirds of the time the wire would be inactive, during which period it could be sued to supply two other lamps constructed on the same principle. According to the doctrine of probabilities, one third of a large number of lamps would be in use all the time. Such being the case, the cost of a conductor would be divided among three lamps. The lamps were so constructed as to burn steadily all the while, although the electricity was passing through them only one-third of the time. Besides the enormous practical value of the electric light, as domestic illuminant and motor, it furnishes a most striking and beautiful illustration of the convertibility of force. Mr. Edison's system of lighting gives a completed cycle of change. The sunlight poured upon the rank vegetation of the carboniferous forests, was gathered and stored up, and has been waiting through the ages to be converted again into light. The latent force accumulated during the primeval days, and garnered up in the coal beds, is converted, after passing in the steam engine through the phases of chemical, molecular and mechanical force, into electricity, which ??? waits the touch of the inventor's genius to flash out into a million domestic suns to illuminate a myriad of homes. |