Edison, His Life and Inventions [151]
with the feeder system under like conditions. The total weight of copper for the four quarter districts by the tree system was 803,250 pounds, but when the feeder system was used it was only 128,739 pounds! This was a reduction from $23.24 per lamp for copper to $3.72 per lamp. Other models emphasized this extraordinary contrast. At the time Edison was doing this work on economizing in conductors, much of the criticism against him was based on the assumed extravagant use of copper implied in the obvious "tree" system, and it was very naturally said that there was not enough copper in the world to supply his demands. It is true that the modern electrical arts have been a great stimulator of copper production, now taking a quarter of all made; yet evidently but for such inventions as this such arts could not have come into existence at all, or else in growing up they would have forced copper to starvation prices.[11]
[11] For description of feeder patent see Appendix.
It should be borne in mind that from the outset Edison had determined upon installing underground conductors as the only permanent and satisfactory method for the distribution of current from central stations in cities; and that at Menlo Park he laid out and operated such a system with about four hundred and twenty-five lamps. The underground system there was limited to the immediate vicinity of the laboratory and was somewhat crude, as well as much less complicated than would be the network of over eighty thousand lineal feet, which he calculated to be required for the underground circuits in the first district of New York City. At Menlo Park no effort was made for permanency; no provision was needed in regard to occasional openings of the street for various purposes; no new customers were to be connected from time to time to the mains, and no repairs were within contemplation. In New York the question of permanency was of paramount importance, and the other contingencies were sure to arise as well as conditions more easy to imagine than to forestall. These problems were all attacked in a resolute, thoroughgoing manner, and one by one solved by the invention of new and unprecedented devices that were adequate for the purposes of the time, and which are embodied in apparatus of slight modification in use up to the present day.
Just what all this means it is hard for the present generation to imagine. New York and all the other great cities in 1882, and for some years thereafter, were burdened and darkened by hideous masses of overhead wires carried on ugly wooden poles along all the main thoroughfares. One after another rival telegraph and telephone, stock ticker, burglar-alarm, and other companies had strung their circuits without any supervision or restriction; and these wires in all conditions of sag or decay ramified and crisscrossed in every direction, often hanging broken and loose-ended for months, there being no official compulsion to remove any dead wire. None of these circuits carried dangerous currents; but the introduction of the arc light brought an entirely new menace in the use of pressures that were even worse than the bully of the West who "kills on sight," because this kindred peril was invisible, and might lurk anywhere. New poles were put up, and the lighting circuits on them, with but a slight insulation of cotton impregnated with some "weather-proof" compound, straggled all over the city exposed to wind and rain and accidental contact with other wires, or with the metal of buildings. So many fatalities occurred that the insulated wire used, called "underwriters," because approved by the insurance bodies, became jocularly known as "undertakers," and efforts were made to improve its protective qualities. Then came the overhead circuits for distributing electrical energy to motors for operating elevators, driving machinery, etc., and these, while using a lower, safer potential, were proportionately larger. There were no wires underground. Morse had tried that at the very beginning of electrical application, in telegraphy, and all
[11] For description of feeder patent see Appendix.
It should be borne in mind that from the outset Edison had determined upon installing underground conductors as the only permanent and satisfactory method for the distribution of current from central stations in cities; and that at Menlo Park he laid out and operated such a system with about four hundred and twenty-five lamps. The underground system there was limited to the immediate vicinity of the laboratory and was somewhat crude, as well as much less complicated than would be the network of over eighty thousand lineal feet, which he calculated to be required for the underground circuits in the first district of New York City. At Menlo Park no effort was made for permanency; no provision was needed in regard to occasional openings of the street for various purposes; no new customers were to be connected from time to time to the mains, and no repairs were within contemplation. In New York the question of permanency was of paramount importance, and the other contingencies were sure to arise as well as conditions more easy to imagine than to forestall. These problems were all attacked in a resolute, thoroughgoing manner, and one by one solved by the invention of new and unprecedented devices that were adequate for the purposes of the time, and which are embodied in apparatus of slight modification in use up to the present day.
Just what all this means it is hard for the present generation to imagine. New York and all the other great cities in 1882, and for some years thereafter, were burdened and darkened by hideous masses of overhead wires carried on ugly wooden poles along all the main thoroughfares. One after another rival telegraph and telephone, stock ticker, burglar-alarm, and other companies had strung their circuits without any supervision or restriction; and these wires in all conditions of sag or decay ramified and crisscrossed in every direction, often hanging broken and loose-ended for months, there being no official compulsion to remove any dead wire. None of these circuits carried dangerous currents; but the introduction of the arc light brought an entirely new menace in the use of pressures that were even worse than the bully of the West who "kills on sight," because this kindred peril was invisible, and might lurk anywhere. New poles were put up, and the lighting circuits on them, with but a slight insulation of cotton impregnated with some "weather-proof" compound, straggled all over the city exposed to wind and rain and accidental contact with other wires, or with the metal of buildings. So many fatalities occurred that the insulated wire used, called "underwriters," because approved by the insurance bodies, became jocularly known as "undertakers," and efforts were made to improve its protective qualities. Then came the overhead circuits for distributing electrical energy to motors for operating elevators, driving machinery, etc., and these, while using a lower, safer potential, were proportionately larger. There were no wires underground. Morse had tried that at the very beginning of electrical application, in telegraphy, and all