Don't assume that the police cant read an ordnance survey.

From 1841, the buildings were taken over by the Ordnance Survey.

Before doing so, you will also need to get agreement from Ordnance Survey for the use of its material.

A party from the Ordnance Survey left after having been stationed here for the last six months.

Study a local map and the Ordnance Survey, which is a mine of information.

It remained a branch of the Ordnance Survey for many years.

The government then appointed him in connection with the Ordnance Survey.

So, get the local sheet of the 1:50,000 Ordnance Survey and lay it out on the table.

It does not appear on Ordnance Survey maps until after the 1840s.

These issues are very different to those of the Ordnance Survey where data is gathered at public expense.