be studied by the experts in the laboratories. (In order to facilitate this extremely important work, there has recently been built a huge concrete reservoir, known as a “recovery-tank,” into which the shell are fired, the fragments being recovered by means of giant magnets.) In the powder-bag department one can see storerooms filled to the ceiling with rolls of the heavy silk used for making the bags in which the propelling charges are contained; in adjoining rooms—“sweat-shops” they are jokingly called—scores of enlisted men, trained in the clothing-shops of New York’s East Side, cut and stitch the silk into cylindrical sacks in sizes to fit the various calibres of guns, and some distance away, in small, isolated buildings, other men fill the sacks with greenish-yellow granules which look like mildewed macaroni, but which is really smokeless powder. Over _ten thousand miles_ of this silk was required for our war programme. And it had to be the finest quality of silk, for no other material could be depended upon not to leave smouldering fragments in the barrel after its discharge, which would mean a burst gun and death to the crew when the next charge was inserted. Everything considered, one can get more thrills and see more things of interest at Aberdeen than at any place I know. When time has given it the justice of perspective, the war-effort of Army Ordnance will be recognized as the greatest industrial achievement in the history of mankind. The more one learns of it the more it staggers the imagination. In nineteen months the Ordnance Department effected the most complete mobilization of science and industry the world has ever seen; it produced munitions of certain classes in unprecedented quantities; it developed and supplied material of such superior design and workmanship as to win the praise of our allies and the grudging admiration of our enemies; it designed, manufactured, and sent overseas the best service rifle, the best automatic rifle, the best pistol, the best machine-gun, the best field-gun, the best railway-artillery, the best tractor, and the best motor-truck possessed by any army in the world, and it stood ready, when the Armistice was signed, to turn loose on Europe such an avalanche of munitions as the world had never dreamed of. The American people seem to have completely overlooked the fact that we had in full swing, after we had been at war less than forty weeks, a mightier munitions programme than Germany could attempt after preparations which took forty years. But, though the American people did not realize the stupendous magnitude of their own effort, the Germans did. It was the news of the programme adopted by Army Ordnance, and the realization _that it was going through_, which, more than any single factor, perhaps, convinced Germany of the utter futility of further resistance. The Ordnance Department, like the biblical prophet, was not without honor save in its own country. VI FIGHTERS OF THE SKY