Ammonium picrate, otherwise known as explosive D in our Army annals, is produced by the ammoniation of picric acid, and because it is more insensitive than picric acid and is less liable to form sensitive salts with metals it is used as the explosive charge for all armor-piercing projectiles. Our average monthly production of ammonium picrate in May, 1917, was 53,000 pounds, and this had been increased without the erection of any Government plants to a monthly capacity in November, 1918, of 950,000 pounds. There was on hand at the time of the signing of the armistice 6,500,000 pounds of this explosive, the average cost of which was 64 cents a pound. Tetryl, on account of its high cost and the lack of manufacturing facilities for its production, was not used except as a loading charge for boosters. It is more sensitive than T. N. T. and has a higher rate of detonation. Only two companies, the du Pont Powder Co. and the Bethlehem Loading Co., manufactured tetryl. Expansion of these two plants increased the monthly capacity of 8,700 pounds in December, 1917, to 160,000 pounds in November, 1918, while its cost was reduced from $1.30 a pound to 90 cents a pound. This increased capacity, however, was not in excess of our explosives requirements, and there was authorized by the Government the erection of a plant at Senter, Mich., that was to be operated by the Atlas Co., and which was to have a monthly capacity of 250,000 pounds. This plant had not reached production when the armistice was signed. The Aetna Powder Co. at the time we entered the war was manufacturing for the Russian Government tetranitroaniline that was to be used in the loading of boosters and fuses. This company's plant at Nobleston, Pa., was destroyed by an explosion. Ordnance officers learned that this material was equal to tetryl as a military explosive. Consequently a contract was entered into with Dr. Bernhardt Jacques Flurschein, the holder of the patent rights, to have manufactured T. N. A. for our own uses. A Government plant was authorized for erection on the ground of the Calco Chemical Co., Bound Brook, N.J., to be operated by that concern. Production at this plant was to be on a cost-plus basis, the estimated cost of the material being 70 cents a pound. When the armistice was signed, about 8,000 pounds of T. N. A. had been produced, but none had been utilized.