The First Phonograph

The patent drawing of the phonograph

Thomas Alva Edison conceived the principle of recording and reproducing sound between in 1877 as a byproduct of his efforts to "play back" recorded telegraph messages and to automate speech sounds for transmission by telephone.

He announced his invention of the first phonograph, a device for recording and replaying sound, on 21 November, 1877 and he demonstrated the device for the first time one week later. Edison presented his own account of inventing the phonograph. "I was experimenting," he said, "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 disc 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 how to 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 tinfoil, which easily received and recorded the movements of the diaphragm. A sketch was made, and the piece-work price, $18, 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 aback 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 got commercial; but here was something there was no doubt of."