Elisha Gray and Alexander Bell telephone controversy

The Elisha Gray and Alexander Graham Bell controversy concerns the question of whether Gray and Bell invented the telephone independently. This issue is narrower than the question of who deserves credit for inventing the telephone, for which there are several claimants.

At issue are roles of each inventor's lawyers, the filing of patent documents, and allegations of theft.

Alexander Graham Bell was a professor of elocution at Boston University and tutor of deaf children while pursuing his own research into a method of telegraphy that could transmit multiple messages over a single wire simultaneously, a so-called "harmonic telegraph". Bell formed a partnership with two of his students' parents, including prominent Boston lawyer Gardiner Hubbard, to help fund his research in exchange for shares of any future profits.

Elisha Gray was a prominent inventor in Highland Park, Illinois. His Western Electric company was a major supplier to the telegraph company Western Union. In 1874, Bell was in competition with Elisha Gray to be the first to invent a practical harmonic telegraph.

In the summer of 1874, Gray developed a harmonic telegraph device using vibrating reeds that could transmit musical tones, but not intelligible speech. In December 1874, he demonstrated it to the public at Highland Park First Presbyterian Church. On February 11, 1876, Gray included a diagram for a telephone in his notebook. On February 14, Gray's lawyer filed a patent caveat with a similar diagram. The same day, Bell's lawyer filed (hand-delivered to the U.S. Patent Office) a patent application on the harmonic telegraph, including its use for transmitting vocal sounds. On February 19, the patent office suspended Bell's application for three months to give Gray time to submit a full patent application with claims, after which the patent office would begin interference proceedings to determine whether Bell or Gray were first to invent the claimed subject matter of the telephone.

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