him as Chairman of the NDRC, and Kistiakowsky became head of Section B. In a reorganization in December 1942, Division B was broken up, and he became head of Division 8, which was responsible for explosives and propellants, remaining in this position until February 1944. Kistiakowsky was unhappy with the state of American knowledge of explosives and propellants. Conant established the Explosives Research Laboratory (ERL) near the laboratories of the Bureau of Mines in Bruceton, Pennsylvania in October 1940, and Kistiakowsky initially supervised its activities, making occasional visits; but Conant did not formally appoint him as its Technical Director until the spring of 1941. Although initially hampered by a shortage of facilities, the ERL grew from five staff in 1941 to a wartime peak of 162 full-time laboratory staff in 1945. An important field of research was RDX. This powerful explosive had been developed by the British before the war. The challenge was to develop an industrial process that could produce it on a large scale. RDX was also mixed with TNT to produce Composition B, which was widely used in various munitions, and torpex, which was used in torpedoes and depth charges. Pilot plants were in operation by May 1942, and large-scale production followed in 1943. In response to a special request for an explosive that could be smuggled through Japanese checkpoints by Chinese guerrillas, Kistakowsky mixed HMX, a non-toxic explosive produced as a by-product of the RDX process, with flour to create "Aunt Jemima", after a brand of pancake flour. This was an edible explosive, which could pass for regular flour, and even be used in cooking. In addition to research into synthetic explosives like RDX and HMX, the ERL investigated the properties of detonations and shock waves. This was initiated as a pure research project, without obvious or immediate applications. Kistiakowsky visited England in 1941 and again in 1942, where he met with British experts, including William Penney and Geoffrey Taylor. When Kistiakowsky and Edgar Bright Wilson, Jr., surveyed the existing state of knowledge, they found several areas that warranted further investigation. Kistiakowsky began to look into the Chapman–Jouguet model, which describes the way the shock wave created by a detonation propagates. At this time, the efficacy of the Chapman–Jouguet model was still in doubt, and it was the subject of studies by John von Neumann at the Princeton Institute for Advanced Study. Kistiakowsky realized that the