| Guns procured from the French Government | 620 |
| Guns ordered manufactured in United States, October, 1917 | 1,200 |
| Increase in order, September, 1918 | 1,397 |
| Total number ordered in United States | 2,597 |
| Total number of guns completed prior to the signing of the armistice | 884 |
| Guns delivered for overseas shipment prior to the signing of the armistice | 300 |
| Guns shipped to various camps in this country | 26 |
| Guns shipped to other points in this country | 4 |
| On hand at Hagerstown Arsenal, proof fired | 425 |
| Completed and ready for proof firing | 129 |
THE 75-MILLIMETER GUNS.
Next in order in the upward scale of sizes we come to the 75-millimeter gun, which was by far the most useful and most used piece of artillery in the great war. In fact the American artillery program might be divided in two classes, the 75's in one class, and all other sizes in the other, since it may be said practically that for every gun of another size produced we also turned out a 75. In number the 75's made up almost half of our field artillery. The 75-millimeter gun threw projectiles weighing between 12 and 16 pounds and it had an effective range of over 5½ miles.
We approached the war production of this weapon with three types available for us to produce—our own 3-inch gun; its British cousin the 3.3-inch gun or 18-pounder; and the French 75-millimeter gun, with its bore of 2.95275 inches. The decision to adopt the 75-millimeter size and modify the other two guns to this dimension, giving us interchangeability of ammunition with the French, was an historic episode in the American ordnance development of 1917.
While in 1917 the French with their excess manufacturing capacity began work on our first orders for 1,068 guns of this size to supply our troops during the interim until American factories could come into production, we were preparing our factories for the effort. Roughly speaking the 75 consists of a cannon mounted on a two-wheeled support for transportation purposes. This support also provides a means for aiming by suitable elevating and traverse mechanisms. As previously explained, a recoil mechanism is also provided to absorb the shock of firing, allowing a certain retrograde movement of the cannon and then returning it in position for the next shot—returning it "into battery," as the artillerists say. By its recuperator device the field gun of to-day is chiefly distinguished from its brother of the latter part of the nineteenth century. Without a recuperator the gun would leap out of aim at each shot and would have to be pointed anew; but one with a recuperator needs to be pointed only at the beginning of the action.
When we entered the war we found ourselves with an equipment of 544 field guns of the old 3-inch model of 1902. This gun had a carriage provided with the old-style single trail. By 1913, however, we had been experimenting with the split trail and it had been strongly recommended by our ordnance experts; and in 1916 we had placed orders for nearly 300 carriages of the split-trail type, which had come to be known as Model 1916. Of these orders 96 carriages were to come from the Bethlehem Steel Co., and the remainder from the Rock Island Arsenal.
Meanwhile for some time the Bethlehem Steel Co. had been engaged in turning out carriages for the British 3.3-inch guns. Here was capacity that might be utilized to the limit; and, accordingly, in May, 1917, we ordered from the Bethlehem Co. 268 of the British carriages. At the same time we ordered from the same company approximately 340 of our own Model 1916 carriages at a cost of $3,319,800. A few weeks later the decision had been made to make all our guns of this sort conform to the French 75-millimeter size, and these British and American carriages contracted for in May were ordered modified to take 75-millimeter guns. The carriages needed little modification and the guns not much. Subsequently, in rapid succession we placed orders with the Bethlehem Steel Co., calling for the construction of an additional 1,130 of the British carriages, all of them to be adapted to 75-millimeter guns.
Next it was the concern of the Ordnance Department to find other facilities for manufacturing carriages for these weapons. The artillery committee of the Council of National Defense located the New York Air Brake Co. as a concern willing to undertake this work; and in June, 1917, this company signed a contract to produce 400 American model 1916 carriages at a cost of $3,250,000.
By December we had the drawings for the French carriages of this size and made a contract with the Willys-Overland Motor Car Co. to produce 2,927 of them. The table at the end of this section shows the production attained at these various plants.