(d) The U.S.S.R. is an even worse third, although it is wise to assume that they are exerting every effort to achieve parity. Whilst preliminary development may have been assisted by the leakages of information in Canada, we do not know to what extent lack of supplies of uranium may limit their output of atomic bombs. (e) No other country deserves consideration for the next five Years, except in respect of research. WORLD RESERVES OF URANIUM ORE 3. In the light of the new information from the Directorate of Atomic Energy, there are large changes in the estimates of the reserves of uranium ore which exist in various parts of the world, as given in our previous survey.