An attack was postponed until 3 September, when Falfemont Farm, Leuze Wood and Guillemont were captured, in an advance of on a front, which eliminated the salient at Delville Wood and exposed Ginchy to attack from the south. Harris also considered that pressure on Rawlinson from Haig led to the capture of Guillemont but criticised Haig for ignorance of the climate of the Somme region, where the weather usually broke around 25 September. Philpott doubted the existence of a "learning curve" but wrote that British methods improved, with principles devised for dealing with isolated German machine-guns, attacks in waves followed by small groups of supporting troops and consolidation of captured ground, spread through the BEF, although fresh divisions had to learn the same lessons, also evident in some French Tenth Army divisions on the south bank. Many errors were made by over promoted and inexperienced officers, while others like Horne, Congreve and Cavan, proved themselves to be talented corps commanders.