On the theory (and it is a correct theory) that all the money put into artillery before the armistice should be charged off as part of the cost of victory, the post-armistice production of field artillery was a prudent transaction for the War Department. By spending $6,000,000 on the completion of 75-millimeter _matériel_ after the armistice, the Government obtained property worth over $14,500,000. By spending $11,000,000 in the 155-millimeter gun project after the armistice, the Government secured artillery worth $18,000,000. By spending $9,000,000 for 155-millimeter howitzers after the armistice, the Government obtained _matériel_ valued at $15,000,000. The storage of the vast reserves of field artillery presented a special problem to the Ordnance Department after the armistice. Not only the guns themselves, but also the accessory vehicles, had to be stored, and the latter outnumbered the guns several times. For example, the American factories built 18,000 caissons and 20,000 caisson limbers for 75-millimeter guns alone, and accessory vehicles in like proportions were brought back from France by the A. E. F. It required about 5,000,000 square feet of storage space to house all the _matériel_. The Rock Island Arsenal was selected as the storage center for field artillery, augmented by storage facilities created at the Savanna Proving Ground in Illinois, the Erie Proving Ground in Ohio, and the Aberdeen Proving Ground in Maryland. Some of the artillery was stored at Raritan Arsenal in New Jersey and at Fort D. A. Russell in Wyoming. For storing the artillery the Ordnance Department used brick warehouses and also portable steel storehouses built originally to protect the reserve American artillery in France. The Ordnance Department retained a complete engineering collection of the captured enemy artillery, one example of every type, and this has been set up as an exhibit at Aberdeen. The collection includes a complete unit of the famous German 42-centimeter howitzer used against the fortifications of Liège and Verdun.