A Balloon Company Manœuvring a Caquot from Winch Position to Its Bed 307 An American Kite Balloon About to Ascend 310 Planes in Battle Formation 311 A Basket Parachute Drop 316 Balloonist Making a Parachute Jump from an Altitude of 7,900 Feet 316 Training the Student Aviator 317 The American Whippet Tank 418 The Mark V Tank 418 A Squadron of Whippet Tanks Advancing in Battle Formation 419 A Squadron of Whippet Tanks Parked and Camouflaged to Conceal Them from Enemy Observation 419 Mobile Machine-Shop Operating in a Village Under Shell Fire 434 Supply of Motor Tires 434 A Motor-Car Wrecked Returning from the Front Lines 435 Field-Hospital 454 An Infectious Ward 454 Clear, Filtered, Disinfected Water 455 Water Station on the Western Front 455 THE ARMY BEHIND THE ARMY I THE EARS OF THE ARMY Before the war made most Americans as conversant with the functions of the various branches of the army as they are with the duties of the gardener and the cook, the work of the Signal Corps troops was popularly supposed to consist, in the main, of standing in full view of the enemy and frantically waving little red-and-white flags. Don’t you remember those gaudily colored recruiting posters which depicted a slender youth in khaki standing on a parapet, a signal-flag in either outstretched hand, in superb defiance of the shells which were bursting all about him? This popular and picturesque conception was still further fostered at the officers’ training-camps, where the harassed candidates spent many unhappy hours attempting to master the technic of semaphore and wig-wag. Yet, as a matter of fact, during more than four years of war I do not recall ever having seen a soldier of any nation attempt to signal by means of flags, save, perhaps, in the back areas. Had such an attempt been made under battle conditions the signaler probably would have provided, in the words of the poet, “more work for the undertaker, another little job for the casket-maker.”