21 Squadron, attacked Cambrai again and hit buildings south of the station. In the evening, air observers were able to plot the progress of the attack on La Boisselle, by spotting flares lit by ground troops and an observer from 9 Squadron, who examined Caterpillar Wood from found it unoccupied, as did an observer who examined Bernafay Wood, which led to the wood being captured that evening and Caterpillar Wood being taken overnight. 4–12 July 4 July was rainy, with low cloud and no German aircraft were seen by British aircrew, who flew low over the German lines, on artillery-observation sorties. In the evening, a large column of German troops was seen near Bazentin le Grand and machine-gunned from the air and the British advance to the southern fringe of Contalmaison was observed and reported. On 6 July, German positions near Mametz Wood and Quadrangle Support Trench were reconnoitred by a 3 Squadron crew, which reported that the defences of Mametz Wood were intact. On 6 July, a 9 Squadron observer saw infantry and transport near Guillemont and directed the fire of a heavy battery on the column, which inflicted many casualties; a German infantry unit entering Ginchy was machine-gunned and forced to disperse. Later in the evening, the crew returned and directed artillery onto more German troops near Ginchy, prisoners later claiming that the battalion lost half its men in the bombardment. Infantry attacks on 7 July, made very slow progress and observers from 3 Squadron reported events in the late afternoon and evening. A crew which flew behind a German barrage saw Quadrangle Support Trench suddenly fill up with troops in field grey uniforms, who repulsed a British attack. British observers were overhead and saw continuous attacks and counter-attacks by both sides until midnight on when Mametz Wood and Quadrangle Support Trenches were captured. The battle for Trônes Wood was also followed by observation-aircraft and at on 12 July, a 9 Squadron observer saw a German barrage fall between Trônes Wood and Bernafay Wood. The observer called by wireless for an immediate counter-barrage, which obstructed a German counter-attack at so badly, that the German infantry were easily repulsed. Bombing of German-controlled railway centres continued on 9 July, with attacks on Cambrai and Bapaume stations, in which two British aircraft were lost. Le Sars and Le Transloy were attacked in the afternoon and Havrincourt Wood was bombed on 11