day and XIII and XV corps would have objectives to be agreed later. On 19 April, Rawlinson wrote that an attempt to reach the German second line on the first day was doubtful, an extension of the attack in the south on Montauban required another division and the inclusion of Gommecourt to the north, was beyond the resources of the Fourth Army. Rawlinson also wrote that long bombardment was dependent on the French, the availability of ammunition and the endurance of gun-crews; the exploitation of a successful attack would need a substantial number of fresh divisions. The process of discussion and negotiation also took place between Rawlinson and the corps commanders and between corps and divisional commanders. For the first time daily objectives were set, rather than an unlimited advance and discretion was granted in the means to achieve them. When the frontage of attack had been decided, corps headquarters settled the details and arranged the building of the infrastructure of attack: dugouts, magazines, observation posts, telephone lines, roads, light railways, tramways and liaison with neighbouring corps and the RFC. For the first time, the army headquarters co-ordinated the artillery arrangements with an Army Artillery Operation Order, in which tasks and timetable were laid down and corps artillery officers left to decide the means to achieve them. On 16 June, Haig discussed the Anglo-French intentions for the campaign, which were to relieve pressure on the French at Verdun, assist Italy and Russia by preventing the transfer of divisions from the Western Front and to inflict losses on the (German army in the west), through the capture of Pozières Ridge from Montauban to the Ancre, the area from the Ancre to Serre to protect the flank, then exploit the position gained according to circumstances. If German resistance collapsed, an advance east would be pressed far enough to pass through the German defences and the attack would turn north, to envelop the German defences as far as Monchy le Preux near Arras, with cavalry on the outer flank to defend against a counter-attack. Should a continuation of the advance beyond the first objective not be possible, the main effort could be transferred elsewhere, while the Fourth Army continued to mount local attacks. On 28 June, the Fourth Army headquarters instructed that if the Germans collapsed, the closest infantry would exploit without waiting for cavalry; the 19th (Western) and 49th (West Riding) divisions