Edison, His Life and Inventions [163]
this he added: "Suppose you want to take the falls down at Richmond, and want to put up a water-power? Why, if we erect a station at the falls, it is a great economy to get it up to the city. By digging a cheap trench and putting in an insulated cable, and connecting such station with the central part of Richmond, having the end of the cable come up into the station from the earth and there connected with motors, the power of the falls would be transmitted to these motors. If now the motors were made to run dynamos conveying low-pressure currents to the public, there is no possible way whereby this high-pressure current could get to the public." In other words, Edison made the sharp fundamental distinction between high pressure alternating current for transmission and low pressure direct current for distribution; and this is exactly the practice that has been adopted in all the great cities of the country to-day. There seems no good reason for believing that it will change. It might perhaps have been altogether better for Edison, from the financial standpoint, if he had not identified himself so completely with one kind of current, but that made no difference to him, as it was a matter of conviction; and Edison's convictions are granitic. Moreover, this controversy over the two currents, alternating and direct, which has become historical in the field of electricity--and is something like the "irrepressible conflict" we heard of years ago in national affairs--illustrates another aspect of Edison's character. Broad as the prairies and free in thought as the winds that sweep them, he is idiosyncratically opposed to loose and wasteful methods, to plans of empire that neglect the poor at the gate. Every- thing he has done has been aimed at the conservation of energy, the contraction of space, the intensification of culture. Burbank and his tribe represent in the vegetable world, Edison in the mechanical. Not only has he developed distinctly new species, but he has elucidated the intensive art of getting $1200 out of an electrical acre instead of $12--a manured market-garden inside London and a ten- bushel exhausted wheat farm outside Lawrence, Kansas, being the antipodes of productivity--yet very far short of exemplifying the difference of electrical yield between an acre of territory in Edison's "first New York district" and an acre in some small town.
Edison's lighting work furnished an excellent basis-- in fact, the only one--for the development of the alternating current now so generally employed in central- station work in America; and in the McGraw Electrical Directory of April, 1909, no fewer than 4164 stations out of 5780 reported its use. When the alternating current was introduced for practical purposes it was not needed for arc lighting, the circuit for which, from a single dynamo, would often be twenty or thirty miles in length, its current having a pressure of not less than five or six thousand volts. For some years it was not found feasible to operate motors on alternating-current circuits, and that reason was often urged against it seriously. It could not be used for electroplating or deposition, nor could it charge storage batteries, all of which are easily within the ability of the direct current. But when it came to be a question of lighting a scattered suburb, a group of dwellings on the outskirts, a remote country residence or a farm-house, the alternating current, in all elements save its danger, was and is ideal. Its thin wires can be carried cheaply over vast areas, and at each local point of consumption the transformer of size exactly proportioned to its local task takes the high-voltage transmission current and lowers its potential at a ratio of 20 or 40 to 1, for use in distribution and consumption circuits. This evolution has been quite distinct, with its own inventors like Gaulard and Gibbs and Stanley, but came subsequent to the work of supplying small, dense areas of population; the art thus growing from within, and using each new gain as a means for further achievement.
Nor was the effect
Edison's lighting work furnished an excellent basis-- in fact, the only one--for the development of the alternating current now so generally employed in central- station work in America; and in the McGraw Electrical Directory of April, 1909, no fewer than 4164 stations out of 5780 reported its use. When the alternating current was introduced for practical purposes it was not needed for arc lighting, the circuit for which, from a single dynamo, would often be twenty or thirty miles in length, its current having a pressure of not less than five or six thousand volts. For some years it was not found feasible to operate motors on alternating-current circuits, and that reason was often urged against it seriously. It could not be used for electroplating or deposition, nor could it charge storage batteries, all of which are easily within the ability of the direct current. But when it came to be a question of lighting a scattered suburb, a group of dwellings on the outskirts, a remote country residence or a farm-house, the alternating current, in all elements save its danger, was and is ideal. Its thin wires can be carried cheaply over vast areas, and at each local point of consumption the transformer of size exactly proportioned to its local task takes the high-voltage transmission current and lowers its potential at a ratio of 20 or 40 to 1, for use in distribution and consumption circuits. This evolution has been quite distinct, with its own inventors like Gaulard and Gibbs and Stanley, but came subsequent to the work of supplying small, dense areas of population; the art thus growing from within, and using each new gain as a means for further achievement.
Nor was the effect