The wrist watch first gained acceptance during WWI. Its small size and utility made it popular with the soldiers. But when it came to precision and coordinated time the pocket watch was still king right up until 1960.
In 1960 Bulova introduced the first electronic wrist watch as well as the first one accurate enough and with the capability of being set precisely to be accepted for use by the railroads. NASA too was interested in a reliable timing device with the same characteristics.
The Bulova Accutron mechanism was based on a battery driven tuning fork that vibrated a 360 times per second and a 'hacking' mechanism that stopped the second hand while the watch was set. That allowed many watches to be precisely set for coordinated timing. The tuning fork also assured an accuracy of only a 2 second a day error or one minute a month. That was far more accurate than the mechanical or automatic watches of the period.
In addition, the watch had fewer parts and only about a dozen total moving parts.
Here is a picture of one of the Bulova Accutron watches. It is the Spaceview model and initially was not meant to be sold but just a demonstrator however there was so much demand that Bulova started producing them in quantity and even kits that allowed jewelry stores to convert a non-Spaceview model.
At the top you can see the electromagnets that controlled the tuning fork.
And the Hummmmmmmm? Well, instead of the tic-tock of a conventional watch, the Accutron has a high pitch hum if you hold it to your ear.
Edited by jar, : appalin spallin
Edited by jar, : get possesive
Anyone so limited that they can only spell a word one way is severely handicapped!