Into the variegated activities of that morning dropped a staff officer of the First Army Corps anxious to get the C.O.’s notes and instructions on mining for new troops who might later have to hold that line “in accordance with the manner taught by experience.” Captain J. H. T. Priestman of the Lincolnshires, a Sandhurst instructor, arrived with him and was attached to the sector for a few days “to see how things were carried on.” As he was being taken round the trenches by the C.O. and the Adjutant, next morning, a private, on sentry with a bomber, tried to throw a bomb on his own account, but, says the Diary, “not knowing how to, he blew himself up and wounded the bomber.” By breakfast time the enemy were shelling the line in enfilade from the direction of Auchy and two men were blown to pieces. A couple of hours later the bombardment was repeated with, from first to last, 6 killed and 9 wounded. The instructor was but one of many whose unregarded duty was to study at first hand every device of the enemy in action and to lecture upon it at the training-centres in England a few days later. The Battalion relieved the Grenadiers once more on the 10th August, after another German mine had been exploded on the salient, and had carried away so much German wire that it seemed possible to effect an entry into their trenches across the new-made crater. A patrol under Lieutenant A. F. L. Gordon was therefore sent out at night but reported the slopes too steep to climb and, since another mine had gone up and destroyed four of our own sap-heads with it, the night was spent in repairing these under intermittent bomb-fire on both sides.