Time ball

It consists of a large, painted wooden or metal ball that is dropped at a predetermined time, principally to enable navigators aboard ships offshore to verify the setting of their marine chronometers.

[1] The first modern time ball was erected at Portsmouth, England, in 1829 by its inventor Robert Wauchope, a captain in the Royal Navy.

[2] One was installed in 1833 at the Greenwich Observatory in London by the Astronomer Royal, John Pond, originally to enable tall ships in the Thames to set their marine chronometers,[3][1] and the time ball has dropped at 1 p.m. every day since then.

[2] The United States Naval Observatory was established in Washington, D.C., and the first American time ball went into service in 1845.

The spectacle—which has given rise to many similar events—was inspired by an organizer having seen the time ball on the Western Union Building in operation.

Royal Observatory, Greenwich , London. Installed in 1833, a time ball sits atop the Octagon Room
The Boston Time Ball (1881)
Sydney Observatory with time ball
The time ball at Port Lyttelton , New Zealand, started signalling Greenwich Mean Time to ships in the harbour beginning in 1876. The Lyttelton Timeball Station was destroyed by an earthquake in 2011 but was rebuilt and reopened in 2018. [ 8 ]
J Shed, Wellington Woolstore, showing the Time Ball at its second site c. 1900
The Time Light arrangement at Dominion Observatory in Wellington c. 1913