Church intersected stations thought..

[Cootking]

There are quite a few of these. From those I've seen there are often 4 spires - I presume only one is the trig. I would have thought it would have been really difficult to sight on this from multiple other stations - the other spires would have 'got in the way'?

[agentmancuso]

True. But the surveyors only needed to view it from two other points, so whichever spire was most visible from those points would have suited their purpose just fine.