In the night of September 3-4, 1918, the Second and Third Canadian Divisions relieved the First and Fourth Canadian Divisions respectively, and the Fourth (British) Division was relieved by the First (British) Division, which had come under the Canadian Corps on September 1, 1918, and had been concentrated after that date in the Monchy-le-Preux, Vis-en-Artois, Guemappe area. The next objective on the Canadian front was now the Canal du Nord. This position, however, was so strongly held and the natural difficulties of the terrain involved were so great that it was decided to make further preparations before attempting this operation which, from its very nature, would have to form part of a larger scheme. The Canadians now held positions which were defensively very strong. The line, therefore, was held very thinly in order to gain an opportunity to rest and refit the divisions. Until September 27, 1918, no changes developed on the Canadian front. Night patrolling and sniping, of course, were kept up. There was also continuous night firing by artillery and machine guns, while the heavy artillery (Brigadier General R. H. Massie) carried out daily wire cutting, counterbattery shoots, and gas concentrations. CHAPTER XIX CAPTURE OF BOURLON WOOD AND CAMBRAI The share of the Canadian Corps in the operations in the direction of Cambrai, toward the preparations of which the best part of September, 1918, was devoted, was at first to be the crossing of the Canal du Nord and the capture of Bourlon Wood and of the high ground to the northeast of it. Later during the month the task of the corps was enlarged to include the capture of the bridges over the Canal-de-l'Escaut, north of Cambrai, and of the high ground overlooking the Sensee Valley. The strength of the corps was increased by attaching to it the Eleventh Division and the Seventh Tank Battalion. At 5.20 a. m., September 27, 1918, the attack was successfully launched, and in spite of all obstacles went well from the first. The barrage was uniformly good, and the Third and Fourth Canadian Divisional Artilleries, commanded respectively by Brigadier General J. S. Stewart and Brigadier General W. B. M. King, were successful in advancing into captured ground, and continued the barrage as planned. Early in the afternoon the first phase of the attack was substantially over, and the readjustments of the fronts preparatory to the second phase were under way. On the extreme right, however, the Seventeenth Corps had failed to keep pace with the Canadian advance, and the latter's right flank, submitted to severe enfilade machine-gun fire from the vicinity of Anneux, had to be refused for a considerable distance to retain touch with the left of the Seventeenth Corps; therefore the encircling movement which was to have given the Canadians Bourlon Wood could not be developed.