Electric Wrist Watch (May, 1952)
Electric Wrist Watch
You never wind the mainspring of an amazing new wrist watch because it has noneâ€”it is powered by a tiny electric motor. No larger than a conventional wrist watch, the electric timepiece runs a year on a tiny battery which has less volume than a penny. The battery is designed so it can be replaced easily by a jeweler. Its power output is at such an even rate that the watch is said to keep better time than conventional watches using mainsprings. The subminiature electric motor (its coils are wound with 3000 turns of insulated copper wire only 1/6 the thickness of a human hair) develops 1/75,000,000 horsepower. Not yet in production, the watch was developed by Elgin National Watch Company.