Maclear's Beacon
Trig beacon on Table Mountain, South Africa
From Wikipedia, the free encyclopedia
Maclear's Beacon is a triangulation station used in Maclear's arc measurement for Earth's circumference determination.
Maclear's Beacon on top of Table Mountain | |
 Interactive map of Maclear's Beacon | |
| Location | Table Mountain, Cape Town, South Africa |
|---|---|
| Coordinates | 33°58′01″S 18°25′32″E |
| Designer | Thomas Maclear |
| Material | Rock |
| Height | 5 metres (16 ft) |
| Completion date | December 1844 |
| Dedicated to | Thomas Maclear |
The beacon is situated on top of Table Mountain in Cape Town, South Africa. It is situated on the Eastern end on the plateau of the mountain, roughly 3 km (1.9 mi) from the Cable Car Station.[1]
The beacon is 1,086 metres (3,563 ft) above sea level, 19 metres (62 ft) higher than the upper cable car station. The structure consists of man made rock packed in a triangle form, being 5 metres (16 ft) high. It was painted in lamp black colour to make it visible, when light shown on it.[2]
In December 1844, the Astronomer Royal at the Cape, Thomas Maclear,[3] instructed his assistant William Mann to build a beacon in the form of a pile of rocks which would be used to confirm and possibly expand on the existing curvature of the Earth data of Nicolas-Louis de Lacaille. This data was in connection with the Cape arc of the meridian.[2] Initially the beacon had no name but in later years it was named after Maclear.[4]
In 1929, the pile of stones collapsed and it was restored in 1979 to commemorate the centenary of Maclear's death.[2]
The beacon is still used by cartographers today. It has become a tourist attraction and hiking trails over the mountain pass next to the beacon. It is also a National Monument.[5][2]
