Gray invented a number of telegraphic devices and in 1869 was one of two partners who founded what became Western Electric Company. On Feb. 14, 1876, the day that Bell filed an application for a patent for a telephone, Gray applied for a caveat announcing his intention to file a claim for a patent for the same invention within three months. When Bell first transmitted the sound of a human voice over a wire, he used a liquid transmitter of the microphone type previously developed by Gray and unlike any described in Bell's patent applications to that date, and an electromagnetic metal-diaphragm receiver of the kind built and publicly used by Gray several months earlier. In the legal cases that followed, the claims of Gray and Bell came into direct conflict, and Bell was awarded the patent. In 1880 Gray became professor of dynamic electricity at Oberlin College, Oberlin, Ohio.