One of the primary roles for the RFC, other that directing artillery fire, is reconnaissance and photography and in particular the impact the British artillery is having on the barbed wire the Germans have in front of their trenches. The wire was an obstacle that Rawlinson and his subordinate commanders are keenly aware of and its destruction is one of the most important missions assigned to the artillery to accomplish before the Fourth Army attacked.
Despite the poor weather, thousands of photographs have been taken were taken during the final week before the start of the offensive. On the afternoon of 26 June there was in fact a pause in the bombardment to allow RFC aircraft to photograph the entire area. The photographs were sent back to RFC HQ for analysis.
One of Rawlinson’s corps commanders reported:
“The aeroplane photographs showed admirably the effect of the bombardment both on the wire and on the trenches and were of the greatest value.”
However in reality, the wire was mostly intact and the limitations of the new science of aerial photography and its interpretation, particularly in poor weather, were exposed.