English: One of the first experimental quartz clocks, invented by physicist Warren Marrison around 1927 at Bell Telephone Laboratories. It keeps time with an electronic oscillator controlled by the quartz crystal under the dome vibrating at 100 kilohertz. The clock's signal is divided down in frequency by vacuum tube counters, and controls the synchronous electric clock on the front. The caption states it keeps time to better than one hundredth of a second per day
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Uploaded a work by {{Unknown|author}} from Retrieved 14 May 2024 from [https://www.worldradiohistory.com/Archive-Electronics/30s/Electronics-1931-05.pdf Electronics magazine, McGraw-Hill Co., New York, Vol., No., May 1931, p.652] without attribution. This publication's copyright would have been renewed in 1959. The [https://onlinebooks.library.upenn.edu/webbin/cinfo/electronics Online Books record of copyright renewals for Electronics] lists no renewals. Therefore it was not renewed and...