Sheet number: 36cNW1. black gridded revision trace, omitting detail and contours, showing British front line, and German dugouts, trench railway, work to be earased, Observation Posts, budied pipeline or cable, and buildings; repaired and mounted on strong tissue (probably archival); part about 2 1/2 x 8 inches missing at east edge (away from trench area); very scarce; good in repaired condition.
