Except in one or two instances, this account of the production of munitions in America for the war against Germany and her allies contains nothing about secret devices invented during the period under discussion. When the necessity for silence with respect to vital matters brought about a voluntary censorship in American publications, the land was filled with rumors of new and revolutionary developments in war matériel, particularly of new weapons of offense. It is fair to the American public to-day to state that such rumors were not without foundation. American inventiveness rose splendidly to the emergency. The expected American offensive in 1919 would have had its "surprises" in numbers, some of which might well have proved to be decisive. Certain of these inventions had been put in large production before the armistice was declared, others had been carried to an advanced experimental stage that insured their success. Since the value of these innovations as part of the Nation's permanent military assets depends largely upon their secret nature, it would be obviously unwise to mention or describe them at this time. The Director of Munitions wishes to acknowledge the debt of America, so far as the production of munitions is concerned, to the Navy for its cooperation in industrial matters at home and its strong aid in the safe transport of munitions to France, and to all the other Government departments, each one of which contributed in numerous and important ways to the success of the munitions enterprise. The debt also extends heavily to the War Industries Board, its functions of creating facilities for manufacture, opening up new sources of raw materials, allocating materials, decreeing priorities, fixing prices, and acting as purchasing agent for the allies, making it the national industrial clearing house through which the War Department could work without waste effort. Acknowledgment is made to such essential agencies as the United States Railroad Administration, the United States Fuel Administration, the War Trade Board, and the United States Food Administration, and to all official or volunteer activities looking to the conservation and mobilization of our national resources. Without this entire cooperation the history set forth in these pages would not be what it is. CONTENTS. Page. Introduction 13 BOOK I--ORDNANCE.