The airplane radio telephone, Col. C. C. Culver and Lieut. Col. Nugent H. Slaughter. Balloons, Capt. H. W. Treat. The Engineers in France, Lieut. Col. J. B. Cress and Capt. C. Beard. Military railways, Col. J. M. Milliken and Mr. S. M. Felton. Engineer activities at home, Lieut. Col. J. B. Cress and Lieut. Col. R. W. Crawford. Sound and flash ranging and searchlights, Lieut. Col. J. B. Cress and Maj. W. D. Young. Toxic gases, Col. M. T. Bogert, Col. W. A. Walker, Lieut. Col. E. M. Chance, and Lieut. Col. William McPherson. Defensive gas equipment, Col. Bradley Dewey and Lieut. Col. A. L. Besse. Subsistence, Lieut. Col. J. H. Adams and Capt. S. B. Johnson. Clothing and equipage, Lieut. Col. F. A. Ellison and Capt. W. H. Porter. Miscellaneous quartermaster undertakings: Music, Maj. George H. Richards; fuel, oil, and paints, Mr. J. Elliott Hall; brushes, Capt. T. W. S. Phillips; rolling kitchens, Capt. J. G. Williams and Mr. M. A. Dunning; tools and tool chests, Mr. W. F. Fusting and Mr. M. E. Moye; hardware, Lieut. Col. H. P. Hill and Mr. William A. Graham; factory enterprises, Lieut. Col. H. P. Hill; shoe fitting, Col. F. A. Ellison; meat cutting, Dr. W. O. Trone; packing, Capt. R. H. Moody; horses and mules, Maj. A. Cedarwald. Motor and horse-drawn vehicles: Motor vehicles, Col. Fred Glover; horse-drawn vehicles, Maj. A. Volgeneau. Medical and dental supplies, Lieut. Col. J. P. Fletcher and Capt. W. G. Guth. Salvage, Col. J. S. Chambers and Capt. F. C. Simpson. Mr. W. L. Pollard, Mr. Aaron Rachofsky, and Lieut. J. J. Cameron have rendered very valuable assistance in assembling data concerning quartermaster activities. Cantonments and camps, and miscellaneous construction, Maj. W. G. Maupin. Signal Corps material, Brig. Gen. C. McK. Saltzman and Capt. Donald MacGregor. The accuracy of all statistics and direct statements of fact has been checked and approved by the statistics branch of the General Staff, under the direction of Maj. W. R. Burgess. Respectfully submitted, BENEDICT CROWELL, _The Assistant Secretary of War, Director of Munitions_. Hon. NEWTON D. BAKER, _Secretary of War_. PREFACE.