The charging floor of an "open-hearth" furnace building, showing two furnaces on the side into which the raw materials are "charged." Each of these furnaces is 75 feet long and 15 feet wide, and the melted steel lies in a shallow bath inside the three doors, into one of which the man is looking. The pool or "bath," as it is termed, is 33 feet long by 12 feet wide and approximately 2½ feet deep, weighs approximately 60 tons, and is composed of pig iron and well-selected scrap steel from previous operations, which are placed in the furnace through the three doors shown, the furnace being all the time at a temperature so high that the naked eye may not look within the furnace, but must be protected with blue glass or smoked glass, exactly as when looking at the noonday sun. The eye can see nothing in the atmosphere of the bath in which the steel is being melted and refined, due to the exceedingly high temperature, which gives a light as white as that of the sun.] [Illustration: FIGURE 5. PRODUCTION OF ARTILLERY AMMUNITION, FRANCE AND UNITED STATES COMPARED WITH GREAT BRITAIN. [Types for use in A. E. F.] MONTHLY RATE AT END OF WAR. _Unfilled rounds_: =Per cent of rate for Great Britain.= Great Britain 7,748,000 ==================== 100 France 6,661,000 ================= 86 United States 7,044,000 ================== 91 _Complete rounds_: Great Britain 7,347,000 ==================== 100 France 7,638,000 ===================== 104 United States 2,712,000 ======= 37 TOTAL PRODUCTION, APRIL 1, 1917, TO NOVEMBER 11, 1918. _Unfilled rounds_: =Per cent of rate for Great Britain.= Great Britain 138,357,000 ==================== 100 France 156,170,000 ======================= 113 United States 38,623,000 ====== 28 _Complete rounds_: Great Britain 121,739,000 ==================== 100 France 149,827,000 ========================= 123 United States 17,260,000 === 14] In artillery ammunition rounds of all calibers America at the end of the war was turning out unfilled shell faster than the French and nearly as fast as the British; but, due to the shortage in adapters and boosters, a shortage rapidly being overcome at the end of the war, the rate of production of completed rounds was only about one-third that of either Great Britain or France. In total production during her 19 months of belligerency America turned out more than one-quarter as many unfilled rounds as Great Britain did in the same time and about one-quarter as many as came from the French munition plants. In completed rounds alone did America lag far behind the records of the two principal allies during 1917 and 1918. (Fig. 5.)