XII
MAKING A MACHINE TALK
If one had never heard a phonograph, it would seem as though it would be impossible to take some pieces of metal and make a machine that would repeat speaking, singing, or instrumental music just like life.
So, before the autumn of 1877, when Edison invented the phonograph, the world thought such a thing was entirely out of the question. Indeed, Edison's own men in his workshop, who had seen him do some wonderful things, thought the idea was absurd when he told them that he was making a machine to reproduce human speech.
One of his men went so far as to bet him a box of cigars that the thing would be an utter failure when finished, but, as every one knows, Edison won the bet, for the very first time the machine was tried it repeated clearly all the words that were spoken into it.
A story has often been told in the newspapers that the invention was made through Edison's finger being pricked by a point attached to a vibrating telephone diaphragm, but this is not true.
The invention was not made through any accident, but was the result of pure reasoning, and in this case, as in many others, fact is more wonderful than fiction. Mr. Edison's own account of the invention of the phonograph is intensely interesting.
"I was experimenting," he says, "on an automatic method of recording telegraph messages on a disk of paper laid on a revolving platen, exactly the same as the disk talking-machine of to-day. The platen had a spiral groove on its surface, like the disk. Over this was placed a circular disk of paper; an electromagnet with the embossing point connected to an arm travelled over the disk, and any signals given through the magnets were embossed on the disk of paper. If this disk was removed from the machine and put on a similar machine provided with a contact point the embossed record would cause the signals to be repeated into another wire. The ordinary speed of telegraphic signals is thirty-five to forty words a minute; but with this machine several hundred words were possible.
"From my experiments on the telephone I knew of the power of a diaphragm to take up sound vibrations, as I had made a little toy which when you recited loudly in the funnel would work a pawl connected to the diaphragm; and this, engaging a ratchet-wheel, served to give continuous rotation to a pulley. This pulley was connected by a cord to a little paper toy representing a man sawing wood. Hence, if one shouted: 'Mary had a little lamb,' etc., the paper man would start sawing wood. I reached the conclusion that if I could record the movements of the diaphragm properly I could cause such records to reproduce the original movements imparted to the diaphragm by the voice, and thus succeed in recording and reproducing the human voice.
"Instead of using a disk I designed a little machine, using a cylinder provided with grooves around the surface. Over this was to be placed tin-foil, which easily received and recorded the movements of the diaphragm. A sketch was made, and the piece-work price, eighteen dollars, was marked on the sketch. I was in the habit of marking the price I would pay on each sketch. If the workman lost, I would pay his regular wages; if he made more than the wages, he kept it. The workman who got the sketch was John Kruesi. I didn't have much faith that it would work, expecting that I might possibly hear a word or so that would give hope of a future for the idea. Kruesi, when he had nearly finished it, asked what it was for. I told him I was going to record talking, and then have the machine talk back. He thought it absurd. However, it was finished; the foil was put on; I then shouted 'Mary had a little lamb,' etc. I adjusted the reproducer, and the machine reproduced it perfectly. I was never so taken back in my life. Everybody was astonished. I was always afraid of things that worked the first time. Long experience proved that there were great drawbacks found generally before they could be made commercial; but here was something there was no doubt of."