From our president, Air Commodore Peter Dye, comes the following answer
to Peter's question:"My sources are two intelligence summaries
produced by the British Army in the SS series (SS 57 dated January 1917 and SS 715 dated
June 1918). The copies I consulted were in the Staff College Library at Camberley but a
complete set exists I believe in the IWM."
Small scale maps used by the Germans were mainly to 1/200,000 and
1/300,000 scales. An edition of the 1/200,000 scale was published for aviators without
contours but with camps, billets, etc printed in red. Large scale maps were mostly
enlargements from, or copies of, French maps.
German squared maps were divided into km squares, the distances in
metres from the origin of the grid lines usually being marked on the margin. The squares
were generally identified by giving each horizontal and vertical run of squares a
letter or number. By 1918, each km square was identified by a 4-figure number in which the
first 2 figures denoted its position in the vertical sense and the last 2 in the
horizontal sense.To locate a position within a square it was sub-divided into 25 numbered
smaller squares, each sub-divided again into 4 lettered squares a, b, c and d. Enemy batteries were identified by separate letter, in alphabetical order (albeit
that a, b, c, d, e, s and u were not used to avoid confusion). Reference points were
identified by using a rough coordinate system (similar to the British), measured from the
NW corner moving East and South, using a 4-figure reference.
