Did Alexander Graham Bell furtively—and illegally—copy part of Elisha Gray’s invention in the race to secure what would become the most valuable U.S. patent ever issued. And afterward, as Bell’s device led to the world’s largest monopoly, the American Telephone and Telegraph Company, he hid his invention’s illicit beginnings. Seth Shulman’s book The Telephone Gambit: Chasing Alexander Graham Bell’s Secret, due out Monday, January 7^th, raises the specter that Bell snookered Gray with the help of aggressive lawyers and a corrupt patent examiner and got an improper peek at patent documents Gray had filed, and that Bell was then erroneously credited with the invention. Bell’s patent was apparently filed right after noon on February 14, 1876. Gray contended to his final days that he filed as soon as the patent office opened that day, around 9AM, but his application languished on the bottom of the pile. Nevertheless Bell was granted U.S. Patent 174,465 for the telephone on 7 March 1876.

Shulman believes the smoking gun is Bell’s lab notebook, which was restricted by Bell’s family until 1976, then digitized and made widely available in 1999. The notebook details the false starts Bell encountered as he and assistant Thomas Watson tried transmitting sound electromagnetically over a wire. Then, after a 12-day gap in 1876 - when Bell went to Washington to sort out patent questions about his work - he suddenly began trying another kind of voice transmitter. That method was the one that proved successful. As Bell described that new approach, he sketched a diagram of a person speaking into a device. Gray’s patent documents, which describe a similar technique, also feature a very similar diagram.

A lot of the argument rest on that Gray was working to perfect ways to transmit multiple message simultaneously on the same telegraph wire. In any case in 1887 Gray invented the “telautograph“, a device that could remotely transmit handwriting through telegraph systems. Gray was granted several patents for these pioneer fax machines, and the Gray National Telautograph Company was charted in 1888 and continued in business as The Telautograph Corporation for many years; after a series of mergers it was finally absorbed by Xerox in the 1990s.