? possible for all other coral concrete. Gamma Station C was next on the schedule of concrete pourtig and was ready Saturday, 14 February. Particular attention was given to this struct~e as the concrete was of heavy scrap steel and Mmonite. NO prenous experiencewith this type of concrete had been encountered, and the problem of h~dl~ng such heavy agg~gate was plainly a job for heavy equipment. The aggregate consisting of nuts, bolts, and other scrap steel was proportionedout by weight and batched into S$gallon steel drums modified so as to be readily picked up by cranes and .iumped into the mixer skip. Limonite and cement were added In the ship. Because of the heavy weight, ~ cu. yd. was set as the maudmum mix for any one batch. The use of this method proved very satisfactory and no difficulties occurred other than usual minor stoppages. The 8 cu. yds. of concrete in the walls and roof’of this structure were poured in two and om half hours. The inside wall forms were stripped from the timing station on 18 February in order to allow representativesof Dr. Krause~s !.~11 group to be@n building a lead brick box, part of the technical installation. The concrete was h excellent condition and no temperature cracks were visible. Meanwhile forma and steel were being placed in position at the blast building, G-a station B, and five type A and two tYP8 B blast footings. Permissionwas obtained to use slotted inserts, where bolts could be placed later, h all.blast foottigs, and the seven that were ready ware poured on 20 and 21 Febmary using coral concrete. Gamma Station B was poured on 2S February. This structure, like Gamma 43 Section XVI