Description: [4th] FSC 8039 29-12-17, grey detail and squaring (without letters and numbers). Area: All of Ypres Salient, from Merckem in north to Armentières in south and Menin in east. Ypres is in left centre. O/p green [4th FSC] 8432 7-3-18, Diagram showing German Grid and Co-ordinate Systems in use opposite [British] Fourth Army Front. Not. That four inches from the bottom of the sheet grid system changes. N. of this a Belgian system based on Brussels is used. S. of this the projection is the same as that used by the French, based on Paris as origin. Not linen-backed.
