During the early stages of the war the average price of T. N. T. for military purposes was $1 a pound. Largely, however, because of the tremendous quantity production and enormous economies effected by reason of this, and despite the scarcity of raw materials, and notwithstanding the greatly increased labor cost, this price had been reduced at the time of the signing of the armistice to 26½ cents a pound. There were in the course of erection at the time of the armistice, two great Government T. N. T. plants--one at Racine, Wis., that was to have a capacity of 4,000,000 pounds a month, and one at Giant, Cal., with a capacity of 2,000,000 pounds a month. During the war three grades of T. N. T. were produced. Grade I was used for booster charges--that is, those charges which initiated the explosive wave in the main shell charge. Grade II was used as a shell filler; while Grade III was utilized with ammonium nitrate in producing amatol. In view of the fact that high explosives were produced in such enormous quantities and that it was necessary to carry on these tremendous manufacturing operations with an inexperienced force, the toll of life taken in the production was remarkably small. Only two explosions of any magnitude occurred in plants where explosives were manufactured and both of these took place in T. N. T. producing plants. One of these happened at Oakdale, Pa., in the plant of the Aetna Explosives Co. in May, 1918. This cost the lives of 100 persons. The other took place on July 2, 1918, at Split Rock, N.Y., in the plant of Semet-Solvay Co., where 60 people lost their lives. At the time of the explosions neither of these plants was operating on War Department contracts. Before the great war about 58,000,000 pounds of ammonium nitrate used in the manufacture of commercial explosives were being produced annually in this country, at an average cost of about 12 cents a pound. By January, 1917, the commercial explosives manufacturers had extended their facilities so that they had increased their production by 1,700,000 pounds monthly. This expansion, however, was insufficient to meet our demands, and a Government ammonium nitrate plant was erected at Perryville, Md. This plant was operated under the supervision of the Atlas Powder Co., who also cooperated in its erection. It did this manufacturing under the Brunner-Mond process that was developed in England under the patents of Capt. Freeth. Under this process ammonium nitrate is produced by the double decomposition of ammonium sulphate and sodium nitrate. In December, 1917, the Atlas people detailed several technical men to go to England and study the Brunner-Mond process as carried on there. In 1918 these men returned to the United States and prepared designs as a result of the information they had gained abroad.