In 2009, J. P. Harris wrote that during the seven weeks' battle for control of Delville Wood, the infantry on both sides endured what appeared to be a bloody and frustrating stalemate, which was even worse for the Germans. The greater amount of British artillery and ammunition was directed by RFC artillery-observers in aircraft and balloons, which increased the accuracy of fire despite the frequent rain and mist. German counter-attacks were tactically unwise and exposed German infantry to British fire power regardless of the value of the ground being attacked. In the Fourth Army sector, the Germans counter-attacked seventy times from September against ninety British attacks, many in the vicinity of Delville Wood. The British superiority in artillery was often enough to make costly failures of the German efforts and since German troops were relieved less frequently, the constant British bombardments and loss of initiative depressed German morale.