[Illustration: FRONTISPIECE. "THE END OF THE WAR." A GRAPHIC RECORD. One minute before the hour. All guns firing. Nov. 11, 1918. 11 A.M. One minute after the hour. All guns silent. This is the last record by sound ranging of artillery activity on the American front near the River Moselle. It is the reproduction of a piece of recording tape as it issued from an American sound-ranging apparatus when the hour of 11 o'clock on the morning of November 11, 1918, brought the general order to cease firing, and the great war came to an end. Six seconds of sound recording are shown. The broken character of the records on the left indicates great artillery activity; the lack of irregularities on the right indicates almost complete cessation of firing, two breaks in the second line probably being due to the exuberance of a doughboy firing his pistol twice close to one of the recording microphones on the front in celebration of the dawn of peace. The two minutes on either side of the exact armistice hour have been cut from the strip to emphasize the contrast. Sound ranging was an important means of locating the positions and calibers of enemy guns. A description of these wonderful devices, which were a secret with America and the Allies, is given in Book III, chapter 4.] America's Munitions 1917-1918 REPORT OF BENEDICT CROWELL THE ASSISTANT SECRETARY OF WAR DIRECTOR OF MUNITIONS [Illustration] WASHINGTON GOVERNMENT PRINTING OFFICE 1919 WASHINGTON, D. C., _December 24, 1918_. DEAR MR. CROWELL: American munitions production, which for some time has been in your charge, played an important part in the early decision of the war, yet the very immensity and complexity of the problem has made it difficult for this accomplishment to be adequately understood by the public or in fact by any except those who have had occasion to give the matter special study. As the whole people have been called upon to make sacrifices for the war, all the people should be given an opportunity to know what has been done in their behalf in munitions production, and I therefore ask that you have prepared a historical statement of munitions production, so brief that all may have time to read it, so nontechnical that all may be able readily to understand it, and so authoritative that all may rely upon its accuracy. Cordially yours, NEWTON D. BAKER, _Secretary of War_.