The world was waiting for it. Scientists and the press reported his invention everywhere. He hung a row of lamps from the trees at Menlo Park, and the thousands who came to see them wondered when they found they could burn day and night for longer than a week. The lamps were small and finely made, they could be lighted or extinguished by simply pressing a button, and the cost of making them was slight. The last doubters surrendered, and admitted that Edison had given the world a new light, and one which was not simply a scientific marvel, but was eminently practical and useful.
But Edison is never satisfied with what he has done in any line; he must try to increase the service each invention gives. Therefore he now conceived the idea of having a central station from which every one might obtain electric light as they had formerly obtained gas. There were gigantic difficulties in the way of such an undertaking. Hardly any one outside of Edison’s own laboratory knew anything about electric lighting, and there were only a few of them who could be trusted to put a carbon filament in an exhausted globe.
He went about this new development in the most methodical way. He got an insurance map of New York City, and studied the business section from Wall to Canal Streets and from Broadway over to the East River. He knew where every elevator shaft and boiler and fire-wall was, and also how much gas each resident used and what he paid for it. This last he learned by hiring men to walk through the district at two o’clock in the afternoon and note how many gas lights were burning, then to make the rounds again at three, and again at four, and so on into the hours of the next morning.
With the field carefully examined he formed the New York Edison Illuminating Company, and had his assistants take charge of factories for making lamps, dynamos, sockets, and the other parts necessary for his lights. It was very difficult to get the land he wanted for his central station, but he finally bought two old buildings on Pearl Street for $150,000. He had little room space and he wanted to get a big output of electricity. So he decided to get a high-speed engine. They were practically unknown then, and when he went to an engine builder and said that he wanted a 150 horse-power engine that would run 700 revolutions per minute he was told it was impossible. But he found a man to build one for him, and set it up in the shop at Menlo Park. The shop was built on a shale hill, and when the engine was started the whole hill shook with the high speed revolutions. After some experimenting and changing they got the power that Edison wanted, and he ordered six more engines like the first.
In the meantime workmen had been busy digging ditches and laying mains through the district that Edison intended to light. The engines were set up in the central station and tried out. Then the troubles began. The engines would not run evenly, one would stop and another go dashing on at a tremendous speed. Edison tried a dozen different plans before he brought anything like order out of that engine chaos. Finally he had some engines built to run at 350 revolutions and give 175 horse-power, and these proved what was required. September 4, 1882, he turned the current on to the mains for the needed light service, and it stayed on with only one short stoppage for eight years.
In this way Edison invented the electric light and evolved the central station that should provide the current wherever it was needed. At the same time he had worked out countless adjuncts to it, the use of the fine copper thread to serve as a fuse wire and prevent short-circuiting, the meter, consisting of a small glass cell, containing a solution in which two plates of zinc are placed, and which shows how much current is supplied, the weighing voltameter, and other instruments for estimating the current, and improvements on the motors and engines. There was no field remotely connected with electric lighting that he did not enter. Yet as soon as the invention was actually before the world business competitors sprang up on every hand. There was more litigation over this than over any other of Edison’s inventions. “I fought for the lamp for fourteen years,” he said, “and when I finally won my rights there were but three years of the allotted seventeen left for my patent to live. Now it has become the property of anybody and everybody.”
Edison and the Early Phonograph
Edison had always wanted a model laboratory, one that should be fitted with the most perfect instruments obtainable, and supplied with all the materials he could possibly require in any of his extraordinary experiments. In 1886 he bought a house in Llewellyn Park, New Jersey, and near the house ten acres of land, on which he built the laboratory of his dreams. Here he had a large force of skilled workmen constantly engaged in developing his ideas, and the expenses were paid by the many commercial companies in which he was interested, and which profited by the improvements he was continually making in their machinery.
Many volumes might be written to tell of the “Wizard’s” achievements. There has been no inventor who has covered such a field, and each step he takes opens new and fascinating vistas to his ever-inquiring eyes. Electricity is always his main study, and electricity he expects in time will revolutionize modern life by making heat, power, and light practically as cheap as air. But other subjects have concerned him almost as much. He ranges from new processes for making guns to the supplying of ready-made houses built of cement. Everything interests him, every object tempts him to try his hand at improving on it.