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 receiver. Gray did not convert his caveat into a patent application until after the caveat had expired and hence left the field open to Bell. When Gray applied for a patent for the variable resistance telephone transmitter, the Patent Office determined "while Gray was undoubtedly the first to conceive of and disclose the (variable resistance) invention, as in his caveat of 14 February 1876, his failure to take any action amounting to completion until others had demonstrated the utility of the invention deprives him of the right to have it considered." The carbon microphone was independently developed around 1878 by