All these parts were unhealthy. The _Rue de Bois_, the street that ran parallel to the firing-trench, about a thousand yards behind the front line, was always under indirect machine-gun fire, yet was, nevertheless, used regularly every night by our transports. It was surprising how few mules were killed. Many times have I skipped, as the bullets struck sparks around my feet. After a while we got to know that "Fritz" had a regular cut-and-dried system in the shelling of these trenches. He always took Mine Ave., Brompton Ave., and Pinney's Ave. alternately, and we later on saved a number of lives by having a sentry at the entrance to these communication-trenches to give warning to use the other trench while this one was being shelled. Weeks later I worked out the enemy's bombardment system more thoroughly, and had such notices as this posted: "Pinney's Ave. dangerous on Mondays, 2 to 6 P. M.," "V. C. unhealthy Tuesday afternoons," and so on. I know I saved my own life several times by watching "Fritz's" _times and seasons_. I am quite sure that each battery "over yonder" had a book that laid down a certain number of rounds to be fired at a certain range on Mondays, and so on for every day in the week. And every relieving battery would take over this "book of instructions." Of course there were times when "Fritz" "got the wind up" (lost his nerve), and then he would shell anything indiscriminately. The god of the German is _Method_, and his goddess _System_, and it hurt his gunners sorely when we tried something new, and made him depart from some long-predevised plan. However, these were discoveries of a later date than the battle which wiped out about 70 per cent of our strength. We had not been two days in the trenches before we knew that we were destined for an attack on the trenches opposite, and we had not had time even to know the way about our own lines. Few of us had even had a glimpse of No Man's Land, or sight of the fellow across the street whom we were to fight. Our guns immediately began to get busy. In fact, too busy for our liking, for they had not yet got the correct range. This was before the days of total aeroplane supremacy, and the battery commander in those days had not an observer flying above where his shells were falling, informing him of the slightest error.