The American-built 155-millimeter howitzer was practically identical with that built in France. Any of the important parts of the American weapon would interchange with those which had come from the Schneider factory. We equipped the wheels of our field carriage, however, with rubber tires, and gave the gun a straight shield of armor plate instead of a curved shield. In the spring of 1917 we bought the plans of the howitzer from Schneider et Cie. and began at once the work of translating the specifications into American measurements. This work monopolized the efforts of an expert staff until October 8, 1917. In order to facilitate the reproduction here, we divided the weapon, as a manufacturing proposition, into three groups--the cannon itself, the carriage, and the recuperator or recoil system--and placed each group in the hands of separate contractors. There was, of course, the usual difficulty in finding manufacturers willing to undertake production of such an intricate device and who also possessed machine shops that had the equipment and talent required for such work, and in procuring for these shops the highly specialized machinery that would be necessary. The American Brake Shoe & Foundry Co., of Erie, Pa., whose magnificent work in building a special plant has been described in the preceding chapter, took an order in August, 1917, for 3,000 howitzer cannon and by October, 1918, was producing 12 of them every day. The company turned out its first cannon in February, 1918, approximately six months after receiving the contract, having in the interim built and equipped a most elaborate plant. It is doubtful if the annals of industry in any country can produce a feat to match this. In fact, the production of cannon by the Erie concern so outstripped the manufacture of carriages and other important parts for the howitzer that it was possible by September, 1918, for us to sell 550 howitzer bodies to the French Government. When the armistice was signed on November 11, 1918, the company had completed 1,172 cannon. In November, 1917, we placed orders for 2,469 carriages for this weapon, splitting the order between the Osgood-Bradley Car Co., of Worcester, Mass., and the Mosler Safe Co., of Hamilton, Ohio. Then followed a long battle to secure the tools and equipment, the skilled mechanical labor, and the necessary quantities of the best grades of steel and bronze, an effort in which the contracting companies were at all times aided by the engineers of the Ordnance Department. All obstacles were overcome and the first carriages were ready for testing in June, 1918. When the armistice was signed 154 carriages had been delivered, and production was moving so rapidly that one month later this number had been run up to 230.