On Pendle Hill, the Corner of a Triangle — Epoche B1
The pillar on Pendle Hill We left Barley village at nine. The path began gently, between hedges and sheep, then turned into a straight stone staircase up the hill's steep eastern face, and conversation stopped. Pendle is 557 metres, no giant, but the last hundred feel honest. On the flat summit stood the thing I had really come for: a waist-high concrete pillar, painted white, scarred by decades of weather. A walker ahead of us slapped its top like an old friend's shoulder and carried on. Set into one side is a brass plate with a number; on top, a metal socket. The pillar is a triangulation point. From 1936 the Ordnance Survey set about remeasuring the whole map of Great Britain, and to do it they built around six and a half thousand of these pillars on high ground from Cornwall to Shetland. The socket on top held a theodolite, an instrument for measuring angles, and here is the design's quiet beauty: each pillar was placed so that at least two others could be seen from it. Measure the angles between your neighbours, hilltop after hilltop, and the country becomes a single net of triangles, every point fixed by the points beside it. Satellites ended all that decades ago. The Survey no longer needs the pillars, but it left them standing; volunteers repaint them, and some walkers spend their weekends collecting them by number. Before the descent I leaned against the concrete and looked for its partners. North across the valley, a far hilltop held one pale dot. We were standing at the corner of a triangle drawn in 1936, and it still had its other corners. References Transport for London (TfL). (2023). The London Underground Map. TfL Publishing.