Edinburgh time ball to be saved

Nelson's Monument © Peter Church

Nelson’s Monument, which sits near the summit of Calton Hill, Edinburgh, is to benefit from a £50,000 donation from the Heritage Lottery Fund.

The monument sits below the famous time ball, which came into use in 1852. Visible from Leith Docks, the ball would be raised to the top of its support, and drop to the bottom at 13:00 GMT each day, allowing the captains of vessels nearby to set their chronometers accurately. Accurate timekeeping at sea was essential in order for the ships’ position to be fixed: latitude is relatively easy to determine from observations of the sun and moon, however longitude requires an accurate knowledge of the local time which allows the longitude to be calculated relative to a known reference. The time ball and the development of the chronometer provided the time, while the establishment of the Greenwich Meridian provided the reference position.

The signal was later supplemented in 1861 by Edinburgh Castle’s one o’clock gun, fired from the castle at the same time each day to provide an audible signal for the sailors.

It seems the ball has not been in operation for more than 18 months, as as the support and mechanism are suffering from their age and the effects of the weather, with numerous parts in need of replacement. Nelson’s Monument is also showing its age in places, and repairs will also be carried out to the stonework.

The work is part of the Twelve Monuments, a partnership between Edinburgh World Heritage and Edinburgh City Council.