It was obvious that the manufacture of this and of other larger mortars would fall into three phases. The forging of barrels, breechblocks, and breech slides was a separate type of work, and we allotted the contracts for this work to the Standard Forging Co., of Indiana Harbor, Ind. The machining of these parts to the fine dimensions required by the design was an entirely separate phase of manufacturing, and we placed this work with the American Laundry Machine Co., of Cincinnati. Still a third class of work was that of assembling the completed mortars, and this contract went to the David Lupton Sons Co., of Philadelphia, who also engaged to manufacture the metal and timber bases and firing mechanisms. These big mortars had to have mobile mountings, and the contract for the mortar carts we placed with the International Harvester Co., of Chicago. These contracts were signed in December, 1917. The Lupton plant had difficulty in securing the heavy machinery it needed for this and for other mortar contracts, its machinery being held up by the freight congestion. Early in 1918 the American Expeditionary Forces advised us to redesign the 240-millimeter mortar to give it a stronger barrel. Consequently all work was stopped until this could be done. The first mortars of the new design to be tested were still unsatisfactory with respect to the strength of the barrels; and as a consequence the Standard Forging Co. urged that nickel steel be substituted for basic open-hearth steel as the material for the barrels. This change proved to be justified. There was also trouble at the shops of the American Laundry Machine Co., its equipment not having the precision to do machining of the type required in these weapons. Accordingly a new machining contract was made with the Symington-Anderson Co., of Rochester, N. Y., which concern was eventually able to reach a production of 20 machined barrels per week. In all we produced 24 of the 240-millimeter mortars in this country. Certain of the parts were manufactured up to the total requirements of the contracts, but others were not built in such numbers. The International Harvester Co. built all 999 carts ordered. The production of shell for these big mortars was another difficult undertaking. After consultation with manufacturers we designed shell of two different types. One of these was a shell of pressed plates welded together longitudinally; and a contract for the production of 283,096 of these was placed with the Metropolitan Engineering Co. The other form was that of two steel hemispheres welded together. The Michigan Stamping Co., of Detroit, undertook to build 50,000 of these.