Sperry Corporation the new automatic pilot. In 1924, following the death of Lawrence on December 13, 1923, the two firms were brought together. The company became Sperry Corporation in 1933. The new corporation was a holding company for a number of smaller entities such as the original Sperry Gyroscope, "Ford Instrument Company", "Intercontinental Aviation, Inc.", and others. The company made advanced aircraft navigation equipment for the market, including the Sperry Gyroscope and the Sperry Radio Direction Finder. Sperry supported the work of a group of Stanford University inventors, led by Russell and Sigurd Varian, who had invented the klystron, and incorporated this
Invention of the telephone David Edward Hughes in England and Emile Berliner and Thomas Edison in the US. Although Edison was awarded the first patent in mid-1877, Hughes had demonstrated his working device in front of many witnesses some years earlier, and most historians credit him with its invention. Thomas Alva Edison took the next step in improving the telephone with his invention in 1878 of the carbon grain "transmitter" (microphone) that provided a strong voice signal on the transmitting circuit that made long-distance calls practical. Edison discovered that carbon grains, squeezed between two metal plates, had a variable electrical resistance that was related