Telephone Device Audibly Announces Exact Time (Apr, 1934)
Telephone Device Audibly Announces Exact Time
DESIGNED primarily to reply to thousands of daily requests received by telephone exchanges for the correct time, a machine invented by John W. Wells, of Stockton, Calif., audibly announces the exact time at three second intervals. The device uses less than 20 feet of movie film to record a 24-hour cycle of hours and minutes.
The sound waves are transformed from the film by a scanning optic and a photo-electric cell which travels the length of the film and returns every six seconds. The time is announced in hours and minutes at every trip of the scanning unit.