The relief of the Seventeenth Corps by the Canadian Corps on July 15, 1918, after the corps' long period of rest and training, with the attendant movement and activity, made the enemy alert and anxious as to the British intentions on this front. He was successful in securing identifications at various points of the line, which he penetrated by raiding. As it was desired to keep him fully occupied on this front, the artillery activity was increased and our infantry engaged in vigorous patrolling and raiding. By the latter part of July, 1918, the Allied High Command had decided to enlarge the scope of the operations east of Amiens. Originally conceived as of a purely local character, they were now intended to reduce the entire salient of the Somme created by the successful German offensive of March 21, 1918, and the days following. During the last few days of July, 1918, and the first few days of August, 1918, the Canadian Corps was relieved by the Seventeenth Corps and was transferred from the First to the Fourth Army area. On July 30, 1918, Canadian Headquarters moved to Molliens Vidarne, in the Amiens sector. The attack against the Somme salient eventually was set for August 8, 1918. The front of attack was to extend from Moreuil to Ville-sur-Ancre on a front of approximately 20,000 yards. The dispositions of the troops participating in the attack were as follows: (a) On the right from Moreuil to Thennes (inclusive)--the First French Army under order of commander in chief British army. (b) In the center from Thennes (exclusive) to the Amiens-Chaulnes Railway--the Canadian Corps. (c) On the left from the Amiens-Chaulnes Railway to the Somme--the Australian Corps. (d) The left flank of the Australian Corps was covered by the Third (British) Corps attacking in the direction of Merlancourt. The object of the attack was to push forward in the direction of the line Roye-Chaulnes with the least possible delay, thrusting the enemy back in the general direction of Ham, and so facilitating the operations of the French on the front between Montdidier and Noyon. The battle front of the Canadian Corps extended from a point about 800 yards south of Hourges to the Amiens-Chaulnes Railway. It crossed the river Luce about 800 yards northeast of Hourges, and remaining well west of Hangard passed through the western portion of Hangard Wood. The total length exceeded 8,500 yards in a straight line. In addition to the four Canadian divisions, the following troops were placed under Canadian Corps for the operation: Fifth Squadron. R. A. F.; Fourth Tank Brigade; Third Cavalry Division.