A visual shutter telegraph system was built here in 1795-6 at the northern end of the Naval Yard. The present building was constructed in 1820-1 with a semaphore mast which was a faster, more versatile and efficient device than the shutter system. It became a timeball station in 1853, to signal the time to ships in the anchorage, and operated until 1927. It is now a museum.
Depending on your device, you can view or download a PDF of the panel which is machine readable and could be translated to another language.
Google map: Latitude: 51.22195; Longitude: 1.40433
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