Field Visit

Date 22 June 2000

Event ID 556528

Category Recording

Type Field Visit

Permalink http://canmore.org.uk/event/556528

RCAHMS Archaeological Field Survey, Ben Lawers

At the summit of Ben Lawers there is a concrete Ordnance Survey triangulation pillar and, 6m to the N, the remains of a direction indicator. The pillar probably stands on the site of a large marker cairn built on the summit in 1878, which in turn replaced a cairn built earlier in the 19th century by the Ordnance Survey.

The triangulation pillar measures 1.2m in height and 0.6m square at the base, tapering to 0.35m square at the top. The central mounting bracket is missing, but the flush bracket bearing the bench mark survives, 0.3m above the base on the N face. It reads 'OS | BM | S1590'. The pillar is fractured near its base and is beginning to rot. In addition, the concrete plinth upon which it stands is badly weathered and undercut on the W side, such that the timber-frame underpinning the foundations is exposed. Triangulation pillars of this type were introduced as part of the retriangulation of Great Britain in 1935-9, though Ben Lawers had previously been used as a trigonometrical station during the Principal Triangulation in the mid-19th century (see NN64SW 3 for the OS camp associated with this survey). A cairn constructed on the summit by the OS was replaced in 1878 by Malcolm Ferguson, who built a monument '45 to 50 feet in circumference and about 20 feet high' capped with a massive block of white quartz (Ferguson 1891). Nothing remains to be seen of Ferguson's cairn.

All that remains of the direction indicator is a flat-topped, conical pillar set on fractured bedrock. It is constructed of small cobbles set in cement, and measures 1.2m in height and 0.9m in diameter at the base, narrowing to 0.56m at the top. The indicator board itself has been removed, as has a plate formerly affixed to its N face.

(BL00 947-8)

Visited by RCAHMS (ATW) 22 June 2000