Digital Images Archive
90. One-inch Third Edition (Large Sheet Series) sheet 107, with military grid
This is one of a few one-inch sheets overprinted during the first world war with military grids in the style of those in use on the western front, presumably for artillery training purposes. This sheet is overprinted in a deep red with a 10,000-yard and quartered 2000-yard grid. The principal squares are lettered A to O, the 2000 yard subdivisions 1 to 25, quartered a to d using pecked lines. The origin is in the north-west corner, with grid lines parallel to the sheet lines of the map.
From a copy now transferred to Cambridge University Library