Tour Scotland video of the One O'clock Gun on visit to Edinburgh Castle. This gun is a time signal, and is fired every day at precisely 1pm, excepting Sunday, Good Friday and Christmas Day. The Time Gun was established in 1861 as a time signal for ships in the Firth of Forth, and complemented the Time Ball which was installed on the Nelson Monument in 1852, but which was useless as a visible signal during foggy weather. The gun could easily be heard by ships in Leith Harbour, 2 miles away. Because sound travels relatively slowly, a map was produced in 1861 to show the actual time when the sound of the gun would be heard at various locations across Edinburgh. The original gun was an 18 pound muzzle loading cannon, which needed four men to load, and was fired from the Half Moon Battery. This was replaced in 1913 by a 32-pound breech-loader, and in May 1952 by a 25-pound Howitzer. The present One O'Clock Gun is an L118 Light Gun, brought into service on the 30th of November 2001.
