Edison in his Laboratory.
It was his success with a device for printing stock quotations upon paper tape that finally induced several New York capitalists to accept Edison's offer to experiment with the incandescent electric light, they to pay the expense of the experiments and share in the inventions if any were made. For the sake of quiet Edison moved out to Menlo Park, a little station on the Pennsylvania road about twenty-five miles beyond Newark, and built a shop twenty-eight feet wide, one hundred feet long, and two stories high. It was here that I first made his acquaintance, in January, 1879, soon after the newspapers had announced that he had solved the problem of the electric light. It may be remembered that gas stock tumbled in price at that time, and there was a rush to sell before the new light should displace gas altogether. One cold day I climbed the hill from the station, and once past the reception-room, in which every new-comer was carefully scrutinized, for inventors are apt to have odds and ends lying about that they do not want seen by everyone, I found myself in a long big work-shop. To anyone accustomed to the orderly appearance of the ideal machine-shop, it presented a curious appearance, for evidently half the machines in it—forges, lathes, furnaces, retorts, etc.—were dismantled for the moment and useless. Half a dozen workmen were busy in an apparently aimless manner.
Upstairs, in a room devoted to chemical experiments, I found Edison himself. He is to-day just what he was then. Prosperity has not changed him in the least, except perhaps in one particular. In those days of struggle the inventor was far less affable with visitors than he is to-day. One felt instinctively that he was a man struggling to accomplish some serious task to which he was devoting every waking thought and probably dreaming about it at night. As I strode across the laboratory in the direction indicated by one of the workmen present, a compactly built but not tall man, with rather a boyish, clean-shaven face, prematurely old, was holding a vial of some liquid up to the light. He had on a blouse such as chemists wear, but it was hardly necessary, as his clothes were well stained with acids; his hands were covered with some oil with which his hair was liberally streaked, as he had a habit of wiping his fingers upon his head. "Good clothes are wasted upon me," he once explained to me. "I feel it is wrong to wear any, and I never put on a new suit when I can help it." Edison has been slightly deaf for a number of years, and like all persons of defective hearing, closely watches anyone with whom he talks. His patience with visitors is proverbial, and provided any intelligence is shown, he will plunge into long explanations. As he goes on from point to point, warming up to his subject, he is sometimes quite oblivious to the fact that it is all lost upon his visitor until brought back by some question or comment which shows that he might as well talk Sanskrit. Then he laughs and goes back to simpler matters.
I watched him for a few moments before presenting myself. After a long look at his bottle, held up against the light, he put it down again on the table before him, and resting his head between his hands, both elbows on the table, he peered down at the bottle as if he expected it to say something. Then, after a moment's brown study, he would seize it again, give it a shake, as if to shake its secret out, and hold it up to the light. As pantomime nothing could have been more expressive. That liquid contained a secret it would not give up, but if it could be made to give it up, Edison was the man to do it, as a terrier might worry the life out of a rat.
Edison's Menlo Park Electric Locomotive (1880).
The secret of his success might well be "Persistency, more persistency, still more persistency." One of his foremen relates that once in Newark when his printing telegraph suddenly refused to work, he locked himself into his laboratory, declaring that he would not come out till the trouble was found. It took him sixty hours, during which time his only food consisted of crackers and cheese eaten at the bench; then he went to bed and slept twenty hours at a stretch. At another time, during the height of the first electric-light excitement, all the lamps he had burning in Menlo Park, about eighty in all, suddenly went out, one after another, without apparent cause. Everything had gone well for nearly a month and the great success of the experiment had been published to the world. If the lamps, with their carbon filaments of charred paper would burn for a month there seemed to be no reason why they should not burn for a year, and Edison was stunned by the catastrophe. The trouble was evidently in the lamps themselves, for new lamps burned well. Then began the most exciting and most exhaustive series of experiments ever undertaken by an American physicist. For five days Edison remained day and night at the laboratory, sleeping only when his assistants took his place at whatever was going on. The difficulties in the way of experimenting with the incandescent lamp are enormous because the light only burns when in a vacuum. The instant the glass is broken, out it goes. Edison's eyes grew weak studying the brilliant glow of the carbon filament. At the end of the five days he took to his bed, worn out with excitement and sick with disappointment. During the last two days and nights he ate nothing. He could not sleep, for the moment he left the laboratory and closed his eyes some new test suggested itself. Neither was there much sleep for his faithful force. Ordinarily one of the most considerate of men, he seemed quite surprised when rest and refreshments were sometimes suggested as in order after fifteen hours' incessant work. The trouble was finally discovered to be one that time alone could have proved. The air was not sufficiently exhausted from the lamps. To add to the discomfiture of the inventor, a professor of physics in one of the well-known colleges declared in a newspaper article widely circulated that the Edison lamp would never last long enough to pay for itself.