these various working machines depend entirely for their existence and freedom to do their work on the success of the fighting machines. The working machines carry guns, and fight when they have to, but the single-seater fighting machines are out for fight all the time, out to destroy enemy fighters, or to put out of action any enemy working machine they can come across. The struggle for the air mastery never ceases, and although it may never be absolute and complete, because the air is a big place to sweep quite clear and clean, the fact that scores of our machines spend all their flying hours anywhere over Hunland from the front lines to fifty miles and more behind them for every one Hun who flies over ours and, after a cruise of some minutes, races back again, is fairly good evidence of who holds the whip hand in the air. All this introduction is necessary to explain properly the importance of the fighting squadrons' job, and why the winning of their fights is of such concern to every man in the Army, and to every man, woman, and child interested in any man in the Army. It also serves to explain why it was that three machines of Naval Number Something "leapt into the air" in a most tremendous hurry-skurry, the pilots finishing the buckling of their coats (one going without a coat indeed) and putting on goggles after they had risen, when the look-out at the Squadron telescope reported that there were four Hun two-seater machines circling round at about 10,000 or 12,000 feet and just far enough over our front lines to look suspiciously like being on a gun-spotting or "Art.-Ob." bit of business.