Two of the first electric (battery powered) watches on the planet from the early 1960's using electronic technology established in the late 1950's that predates anything quartz. At the time it was pretty complex stuff that represents the best of early space-age technology.
The Hamilton 505 Electric on the left uses a principle of physics that when the current is passed through a wire placed in a magnetic field, a torque is placed on that wire and thus drives the balance wheel.
The Bulova Accutron 214 'Spaceview' on the right uses a principle where an electric signal is transformed by a transistor and activates an electromagnetic coil that puts a metal tuning fork into vibration. This vibration is then transferred by means of a tiny wire called index finger onto an ordinary mechanical gear train.
![](https://s2.save4k.ru/pic/cUTzXvzmWSk/maxresdefault.jpg)