Shinkle and Major A. B. Quinton, Jr., of the Ordnance Department; Major-General George S. Squier, Chief Signal Officer of the Army, Brigadier-General C. McK. Saltzman and Lieutenant-Colonel Joseph O. Mauborgne of the Signal Corps; Major-General M. W. Ireland, Surgeon-General, and Colonel M. A. De Laney of the Medical Corps; Brigadier-General Marlborough Churchill, Director of Military Intelligence, Captain R. G. Martin, Captain A. R. Townsend, Captain H. M. Dargan, and Captain J. Stanley Moore, of the Military Intelligence Division; Major-General Rogers, Quartermaster-General of the Army; Colonel I. C. Welborn, Director of the Tank Corps; Brigadier-General Drake, Director of the Motor Transport Corps; Captain W. K. Wheatley, Chief of the Historical Section of the Motor Transport Corps, and W. L. Pollard, Esq., Chief of the Historical Branch of Purchase and Storage, all showed me exceptional courtesy and afforded me every possible assistance. I welcome this opportunity to express to them my appreciation. To the _Bulletin of the Spruce Production Division_, published by the Loyal Legion of Loggers and Lumbermen, I am indebted for a considerable portion of the account of spruce production in the Pacific Northwest. E. ALEXANDER POWELL. CONTENTS PAGE THE EARS OF THE ARMY 1 “ESSAYONS” 47 THE GAS-MAKERS 101 THE “Q. M. C.” 140 ORDNANCE 197 FIGHTERS OF THE SKY 259 “M. I.” 328 “TREAT ’EM ROUGH” 409 “GET THERE!” 424 MENDERS OF MEN 437 ILLUSTRATIONS The Burning of an Observation Balloon at Fort Sill, Oklahoma _Frontispiece_ FACING PAGE Laying a Field Telegraph Line 8 Signal-Corps Men Erecting a Field Telephone 8 Signal-Corps Men at Work Repairing the Tangle of Copper Wires Which Link the Infantry in the Front-Line Trenches with the Guns 9 Communication by Use of Panels 14 A Member of the Signal Corps Sending Messages by Means of a Lamp 15 Motion-Picture Operators of the Photographic Section of the Signal Corps Going into Action on a Tank 34 An Officer of the Signal Corps Operating a Telephone at the Front 35 New Type of Search-Light Used in the American Army 80 Camouflaging a Divisional Headquarters in the Toul Sector 81 Suits Known as Cagoules 94 The Work of the Camouflage Corps 95 Man and Horse Completely Protected Against Poisonous Gas 132