When it is considered that the personnel of the Ordnance Department, at home and overseas, consisted of 6,000 officers and nearly 100,000 enlisted men—almost as many as we had in the entire Regular Army before the war—and that these officers and men were called upon to perform work of a highly technical and specialized nature, it will be seen how important was the work of the Training Division. Among the innumerable activities of this division was the Ordnance Engineering School, where in three months a technically trained engineer was given an insight into the design and manufacture of ordnance materials; the Powder School at Carney’s Point; the Ordnance Supply School at Fort Hancock, and the Machine-Gun School at Springfield. In addition to these there was a school for tractor operators, a school for instruction in the repair and maintenance of ordnance trucks, another for the repair and maintenance of railway-artillery, and still another for training men in the repair of optical and precision instruments. It is sufficient for an infantryman to know how to use a pistol, a rifle, and a machine-gun, but the men who wear on their collars the insignia of the Ordnance Department have to know not only how to operate those weapons, and how to give instruction in their operation to others, but they have to be familiar with every detail of their manufacture and repair. By far the most fascinating feature of Ordnance activities in America is the great proving-ground at Aberdeen, Maryland, thirty miles from Baltimore, on the shores of Chesapeake Bay. On this remote and jealously guarded reservation is tested every weapon and device, with the exception of small arms, produced by the Ordnance Department. During the height of our war preparations, more shots were fired here in a single day than were fired at the old proving-grounds at Sandy Hook in a year. A far greater quantity of explosive was expended daily than was used in many of the important battles of the Civil War. Here can be seen in action every type of American artillery from the vicious, hard-hitting little 37-mm. infantry cannon to the camouflaged monsters on railway-mounts, streaked like zebras and spotted like giraffes, which can drop a ton of explosive on a given target thirty miles away. Giant tanks, looking for all the world like some strange species of prehistoric monster, smash their way through patches of woodland or take twelve-foot trenches in their stride; field-guns of all calibres, camouflaged and tractor-mounted, go rocking and reeling across the broken fields; airplanes, circling in the blue, drop their half-ton bombs upon the targets marked out on the fields below; showers of shrapnel from the antiaircraft guns burst about the target parachutes in suddenly unfolding blossoms of white and scarlet. In the recovery-fields hundreds of men are at work with pick and shovel retrieving the fragments from the shell-bursts in order that they may