“Under such treatment the charcoal is given a high degree of activation without the usual accompanying high losses. Seemingly the oxidizing medium used, together with the operating conditions, produce a deep penetration of the charcoal particles without increasing the extensive surface combustion experienced in the steam activators. The capacity of such a type furnace is limited only by the size of the installation. “The advantages of this type furnace may be tabulated as follows: 1—High quality of product. 2—Small weight and volume losses. 3—Large capacity per unit. 4—Minimum initial cost and maintenance of installation. 5—Simplicity and cheapness of operation. 6—Adaptability to activation of all carbon materials. 7—Availability of furnaces of this general type already constructed.” SUBSTITUTES FOR NUT CHARCOAL The first experiments were made with a special anthracite coal (non-laminated and having conchoidal fracture). This had a life of 560 minutes as against 360 minutes for air treated cocoanut charcoal and 800-900 minutes for steam-treated charcoal. When the Gas Defense Service tried to activate anthracite on a large scale in vertical gas retorts at Derby, Connecticut, the attempt was a failure. They carbonized at 900° and then turned on the steam with the result that the steam-treated coal had a slightly greater density than the untreated, which was wrong, and had a shiny appearance in parts with roughened deposits in other parts. When the hydrocarbons are decomposed at high temperatures, the resulting carbon is somewhat graphitic, is itself inactive, is not readily oxidized, and impairs or prevents the activation of the normal carbon upon which it is deposited. This discovery made it possible to treat anthracite successfully. The conditions must be such as to minimize high temperature cracking, to carry off or oxidize the hydrocarbons as fast as formed, and especially to prevent the gases from cooler portions of the treater coming in contact with carbon at a much higher temperature. With these facts in mind, a plant was built at Springfield which produced 10 tons a day of 150-300 minute charcoal from raw anthracite. This was one-third of the total production at that time and was mixed with the nut charcoal made at Astoria, thereby preventing an absolute shortage of canister-filling material in October, 1918. It was next shown that the cocoanut charcoal fines resulting from grinding and screening losses and amounting to 50 per cent of the product, could be very finely ground, mixed with a binder, and baked like ordinary carbon products. By avoiding gas-treating in the bake, the resulting charcoal is nearly as good as that from the original shell. A recovery plant for treating the cocoanut fines was built at Astoria. The product was called “Coalite.”