IBM Master Clock - Slave Clock Automatic Correction. How it works
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Self Winding Master Clock Hourly Synchronizer - How it works
10:01
IBM Slave (Secondary) Clock evolution and operation.
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How does a No. 1 Crossbar work? - Dial Equipment Appreciation, Part 2
11:52
Westerstrand Impulse Clock
8:31
The Underground Clocks of Paris
4:00
A Compact ball clock with chime
14:12
IBM Master Clocks, Timekeepers of the Industrial Age. An ITM Clock video
4:49