Known locally as the “Sentinel of Semaphore,” the Time Ball Tower was built in 1875. Other similar towers were set up in cities around the world, the first being built at Portsmouth in the United Kingdom in 1829. The solid stone structure features a black ball that dropped at 1 p.m. every day, signaling ships to rate their chronometers that are used as vital navigation instruments.

The Semaphore Time Ball Tower was built by Henry Burge. The stone tower featured a ball measuring about five feet in diameter, large enough to be visible to ships offshore. Every day at 12:55 p.m., the ball would be raised to half-mast. Five minutes later, at precisely 1 p.m., it would be dropped by an electric command from the nearby observatory.

Semaphore’s Time Ball first went into service on August 2. 1875. It performed its daily duties for more than 50 years before being retired on February 1, 1932. The tower remains in place near the docks, and in 1992 it was restored. A new mechanism was installed that operates the Time Ball with an electric motor. Once again, the ball drops every day at 1 p.m on the dot.