The Salvage Service has been one of the least advertised, as it has been one of the most efficient, branches of the army. Probably not one out of a thousand readers of this book was previously aware of its existence. Yet during the twelve months of 1918 it saved to the government, either in articles repaired and reissued or in materials saved and sold, _one hundred and one millions of dollars_. (If this does not impress you, let me remind you that the entire appropriation for the support of the army for 1898—the year of the Spanish-American War—was only a little over $70,000,000.) It has developed what was formerly a liability into a tremendous asset. It has conserved untold quantities of raw materials at a time when those materials were most vitally needed and were most difficult to obtain. By again and again repairing and using worn-out clothing and equipment and thereby permitting the shipment of vital necessities, it saved thousands of tons of shipping at a time when every ton counted. If, in this impressionistic sketch of the activities of the Salvage Service, and of its parent, the Quartermaster Corps, I seem to have indulged too freely in the use of figures, it is because those figures are of vital concern to _you_. They represent _your_ dollars, Mr. Reader; they show where the money from _your_ Liberty Bonds has gone. V ORDNANCE The history of mankind is punctuated by a few examples of endeavor which, by reason of their magnitude, cannot be fully comprehended by the human mind. That phase of America’s part in the Great War comprised in the work of the Ordnance Department of the Army is one of them. It has been termed, and without exaggeration, the greatest effort, directed by a single head, of all time. It was incomparably the greatest industrial undertaking that the world has ever seen. Therein lies the difficulty of writing an adequate story of ordnance—it is too big, too complex, for any writer entirely to grasp, for any reader completely to comprehend. It is like attempting to describe the grandeur of the Grand Canyon; so stupendous a thing can neither be translated into words nor encompassed by the mind. The best that I can hope to do is to sketch a few of the most salient features of the great story in barest outline.