When the war touched us our strategical equipment included plans ready drawn for the mobilization of men. There were on file at the Army War College in Washington detailed plans for defending our harbors, our coasts, and our borders. There were also certain plans for the training of new troops. It is worthy of note, however, that this equipment included no plan for the equally important and equally necessary mobilization of industry and production of munitions, which proved to be the most difficult phase of the actual preparation for war. The experience of 1917 and 1918 was a lesson in the time it takes to determine types, create designs, provide facilities, and establish manufacture. These years will forever stand as the monument to the American genius of workshop and factory, which in this period insured the victory by insuring the timely arrival of the overwhelming force of America's resources in the form of America's munitions. B. C. WASHINGTON, _May, 1919_. BOOK I. ORDNANCE. CHAPTER I. THE ORDNANCE PROBLEM. To arm the manhood called to defend the Nation in 1917 and 1918, to make civilians into soldiers by giving them the tools of the martial profession--such was the task of the Ordnance Department in the late war. The off-hand thought may identify ordnance as artillery alone. It may surprise many to know that in the American ordnance catalogue of supplies during the recent war there were over 100,000 separate and distinct items. Thousands of the items of ordnance were distinctly noncommercial, meaning that they had to be designed and produced specially for the uses of war. While the principles of fighting essentially have changed not one whit since the age when projectiles were stones hurled by catapults, nearly every advance in mechanical science has had its reflection in warfare, until to-day the weapons which man has devised to destroy the military power of his enemy make up an intricate and an imposing list. When America accepted the challenge of Germany in 1917, part of the range of ordnance had already been produced in moderate quantities in the United States, part of it had been developed by the more militaristic nations of the world in the last decade or quarter century, and part of it was purely the offspring of two and one-half years of desperate fighting before America entered the great struggle. Yet all of it, both the strange and the familiar, had to be put in production here on a grand scale and in a minimum of time, that the American millions might go adequately equipped to meet the foe. Let us examine the range of this equipment, seeing in the major items something of the character of the problem which confronted the Ordnance Department at the outset of the great enterprise.