Watchlords

In March 1952, the Elgin Watch Company announced the first battery-powered mechanical wristwatch, a laboratory prototype of what would become the Elgin Grade 725. This early electrical movement, described as the greatest advance in timekeeping in 450 years, was functionally identical to a traditional mechanical movement, minus the mainspring power source. Beat regulation was still governed by a conventional balance wheel and hairspring escapement, and accuracy was comparable to a fully mechanical movement of similar quality.

Coinciding with the development of the Elgin Grade 725 was the Hamilton 500, which would become the world's first commercially viable electromechanical watch. Although Elgin and Hamilton had long been known for technological innovation, their singular novelty of electric power would prove to be far less ambitious than Bulova's response. Bulova's answer to modern timepiece design would be so fundamentally revolutionary, that it would ultimately drive Elgin and Hamilton out of the watch business altogether.

After examining the Elgin electric movement, Bulova assigned electronics engineer Max Hetzel to produce a new type of electronic movement which would exceed the accuracy of a conventional mechanical or electrical watch. By 1953, Hetzel received his first shipment of Raytheon CK722 transistors, and began constructing the first prototype of what would be known as the Accutron chronometric micro-powerplant, a new type of timekeeping mechanism with a tuning fork timebase.

http://www.decadecounter.com/accutron/history.htm