The catalyst for action was the sudden availability of a new improved Ramsden theodolite which had been intended for the East India Company and the purchase of this instrument on 21 June 1791 by the Board is taken as the inauguration of the Ordnance Survey.
The catalyst for action was the sudden availability of a new improved Ramsden theodolite. This new improved Ramsden theodolite had been intended for the East India Company. The purchase of this instrument on 21 June 1791 by the Board is taken as the inauguration of the Ordnance Survey.