[Z400AF], Letter from Thomas Alva Edison to Theodore Puskas, February 12th, 1878


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Edison to T. Puskas: The fact to be accomplished by me is the inventioon, perfection, and introduction into practice of a complete system of illumintating by electricity which shall effect every object and take the place of the present method of lighting by gas That the cost of any light, or any number of lights equal in candle power to gas is to be but one third that of the latter. That the cost of the plant shall be no greater than that of gas. That after introduction it shall work as satisfactorily as regards disarrangement as the gas systems of New Yrok. To the present date (April 8, 78) I have sub-divided the light into 20 burners each burner being equal to 16 candles, or one gas jet. There is no obstacle to further sub-division the requirements being, more lamps, generators, and an additional supply of power which is analogous to more retorts furances &c in gas making. That any electric lamp may be turned up or down the same as gas. I have demonstrated that for every horse power taken from the engine that six electic jets are obtained each equal to a gas jet which brings the cost to 1/3 that of gas. That there is not as much waste of enegy by leakage or otherwise as in gas. that the major portion of plant is salable at a small sacrifice after the lapse of any length of time. That I can measure by means of extreme simplicity the amount of electricity consumed by each customer. That remaining to be accomplished is, 1st The proper generator both in regard to economy in construction and amount of electricity generated per horse power applied, its reliability and adaptability to my system. 2d A standard lamp free from all mechanical objections, and of the most extreme simplicity that his attainable. A tst at Menlo Park with 500 lights placed int he surrounding houses and upon posts over the whole of the Park about 1/2 mile square of from 3 to 5 months duration 24 hours daily to ascertain the permanency of the lamps and to bring out under my supervision the inevitable disarrangement which occur in all new systems of industry. All these defects being eradicated the system will be turned over to the Company in New York.









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[Z400AF], Letter from Thomas Alva Edison to Theodore Puskas, February 12th, 1878

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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University


February 12, 1878