The discovery of fission raised the possibility that an extremely powerful atomic bomb could be created. The term was already familiar to the British public through the writings of H. G. Wells, in his 1913 novel "The World Set Free". Sir Henry Tizard's Committee on the Scientific Survey of Air Defence was originally formed to study the needs of anti-aircraft warfare, but branched out to study air warfare generally. In May 1939, a few months before the outbreak of the Second World War in Europe in September 1939, it was directed to conduct research into the feasibility of atomic bombs. Tizard tasked George Paget Thomson, the professor of physics at Imperial College London, and Mark Oliphant, an Australian physicist at the University of Birmingham, with carrying out a series of experiments on uranium. By February 1940, Thomson's team had failed to create a chain reaction in natural uranium, and he had decided that it was not worth pursuing.