While I was with the Canadians, all attacks, or rather advances, were launched in four waves, the waves being thirty to fifty yards apart. A wave, I might explain, is a line of men in extended order, or about three paces apart. Our officers were instructed to maintain their places in the line and to wear no distinguishing marks which might enable sharpshooters to pick them off. Invariably, however, they led the men out of our trenches. “Come on, boys, let’s go,” they would say, climbing out in advance. It was bred in them to do that. Experience had taught us that it took the German barrage about a minute and a half to get going after ours started, and that they always opened up on our front line trench. We had a plan to take advantage of this knowledge. We usually dug an “assembly trench” some distance in advance of our front line, and started from it. Thus we were able to line up between two fires, our shells bursting ahead of us, and the Germans’ behind us. All four waves started from the assembly trench at once, the men of the second, third and fourth waves falling back to their proper distances as the advance proceeded. The first wave worked up to within thirty to fifty yards of our own barrage and then the men lay down. At this stage, our barrage was playing on the enemy front line trench. After a certain interval, carefully timed, the gunners, away back of our lines, elevated their guns enough to carry our barrage a certain distance back of the enemy front trench and then our men went in at the charge, to occupy the enemy trench before the Germans in the dug-outs could come out and organize a defense. Unless serious opposition was met the first wave went straight through the first trench, leaving only a few men to guard the dug-out entrances pending the arrival of the second wave. The second wave, only a few seconds behind the first one, proceeded to do the “mopping up.” Then this wave, in turn, went forward, leaving only a few men behind to garrison the captured trench.