The enemy, on his side, is no less ingenious and probably more painstaking. There was a certain water-tower that stood in a wood, with its top just visible above the surrounding trees. Imperceptibly, as the days went by, it seemed to grow out of the wood, until a month or so after we first noticed it, about ten feet of it were visible. The solution appears to have been that, to increase the field of view, all the trees in front of it, and there must have been two or three hundred of them, were very cautiously pruned every night, so as to show no apparent alteration from day to day, but gradually to allow the required observation. It sometimes happens that it is necessary for the observing officer to remain night and day in the post, and under such circumstances continual interest is necessary if life is not to become very dull. Frequently the enemy are good enough to provide this interest, an unexpected shell now and again either just over or just short is a powerful antidote against ennui. More often our own headquarters, with a laudable intention of preventing one's interest from flagging, send one encouraging messages--"Can you see a hostile working party at such-and-such a place? If so, kindly keep under observation and report half-hourly," or "Infantry report flashes of hostile battery in the direction of Hill 0, observe and locate if possible." One observes till one's eyes ache as the light grows too bad to see, when a second message comes, "Flashes reported by infantry ascertained to be caused by summer lightning." At night one crawls into the dug-out and endeavours to slumber with one ear glued to the telephone, and, strangely enough, despite the presence of two loud-sleeping telephonists, one usually does.