1 July 2009: Nelson Monument, Edinburgh

Built between 1807 and 1815 by the architect Robert Burn, the Nelson Monument on Calton Hill commemorates Admiral Lord Nelson’s victory – and death – at the Battle of Trafalgar in 1805.

Standing 32m high and 171m above sea level, the monument was designed to look like an upturned telescope. In 1852, a zinc and timber sphere that became known as the ‘time ball’ was added to the top of the structure. Raised and lowered every day at 1300 BST, the ball was clearly visible to ships moored in the Firth of Forth, allowing captains to set their chronometers for accurate navigation.  Weighing 762kg, the ball was removed in 2007 after suffering storm damage.

The replacement of the time ball this week is part of the ongoing Twelve Monuments Restoration Project, a partnership between the City of Edinburgh Council, Edinburgh World Heritage, charitable trusts and business donations.

This early nineteenth century engraving shows the Nelson Monument before the original addition of the time-ball.