On the 21st November 1877, American inventor Thomas Edison announced his phonograph, the world’s first practical machine that could record and play sound using a cylinder. Although Frenchman Charles Cros presented plans for a sound recording and reproduction machine called a paleophone earlier that year, the machine was never actually built. Edison made the first demonstration of his phonograph on the 29th November and patented it the following February. Within two decades it had spawned an entire industry built around the recording, distribution and sale of sound recordings.
Edison’s original phonograph was developed as a result of experiments that aimed to record telegraph messages. He had worked with diaphragms during his work developing the carbon microphone for telephones, and was aware that if you could inscribe the movements of the diaphragm he could effectively ‘record’ sound.
His first recording medium was a grooved cylinder covered with tin foil. As the cylinder rotated, an arm attached to a diaphragm would make an indentation of the movement into the tin foil. The arm moved up and down the cylinder, embossing the recording. By adjusting the machine, the arm could then be used to play back the recorded sound through a horn. The first machine was hand-cranked, but it worked well enough to impress everyone who heard it. Within six months he had demonstrated it to scientists and representatives of the government in Washington DC.
Although heralded as a ‘genius’ by the Washington Post, Edison did very little with his invention. Within a few years, however, other inventors developed engraved wax cylinders and – later – flat disks to record sound.
