Posted by David Mottershead at 20:10 on 2012 Jul 18
Many thanks Roy, appreciated. I think, looking at the symbol that accompanies the notation ‘BM 249.5’ that this is a benchmark, and if so there must have been some structure for the benchmark to be on. According to the Ordnance Survey, benchmarks are normally only encountered on buildings and other semi permenant structures. Certainly by the later maps on Old Maps both the observatory and benchmark had gone. So this could well be the observatory referred to. Many thanks again.