Of course, it is an unpardonable crime to do anything in or near an O.P. which might draw the enemy's attention to it. A battery of my acquaintance had for some weeks been installed in a pretty little villa residence of which they were very proud, situated on the outskirts of a mining village. They had certainly spared no pains to make it comfortable or safe; indeed, the interior was a solid mass of sandbags through which a sort of tunnel ran to the little observation chamber, elaborately reached by a series of ladders and passages. One day the battery commander was conducting a deliberate and deeply calculated series, his mind too full of figures and angles to allow room for any idea of possible molestation by the enemy. Suddenly, directly behind the house, he heard a series of violent explosions. In rather less than the proverbial twinkling of an eye he was down below in the dug-out, nearly flayed by violent contact with ladders and other unyielding substances, but still alive and safe. Still the explosions continued, but no shell seemed to strike the house. At last one of his telephonists, more daring than the rest, ventured to peer out, and there, right in the sacred enclosure, was an armoured car in full and noisy action. The scene that followed baffles description. Two heads, one thrust through the hatchway of the car, one cautiously hidden behind a projecting sandbag, discussed the question of unmentionable idiots who wheeled their indescribable tin perambulators into other people's preserves, until the hardy navigators in the car and the stalwart gunners in the O.P. blushed to hear them. Finally, upon a reiterated threat from the major to turn his own battery on to the car if it did not move off, the nuisance was abated. But "Sans Souci," as we called the place, was never its old self again, its restful charm had departed. Some hostile battery had seen the flashes of the car's gun, and afterwards, at uncertain intervals, presumably when things were dull with it, would fire a few rounds in friendly greeting.