21st Divisional Artillery Instruction 22 June 1916
15/CA 10/72
SECRET
7th Divisional Artillery
21st Divisional Artillery
17th Divisional do (for information)
XV Corps Heavy Artillery
With reference to the final bombardment and barrages on Z day, all Artillery Officers must be careful not to fire on their objective after Zero, or the various times given in the lifts.
They must remember the time of flight of their shells and arrange to stop so that the last shells will arrive at Zero, not the last gun be fired at that time. This is necessary in order that the Infantry may know exactly when to move forward.
E.W. Alexander
Brigadier General. R.A. XVth Corps
22nd June 1916
Am sending 1copy per battery.