Since the atoms of both U-235 and Pue239 are norma extremely stable (in technical language: possess a long "half—life"), subcritical masses of either material may be stored practically indefinitely. Thus, even a relatively slow rate of production can result over a period of time in a substantial accumulation of bombs, But how slow need the rate of production be? The process of produc- tion itself is inevitably a slow one, and even with a huge plant it would require perhaps several months of operation to produce enough fissionable material for thefirst bomb, —_ fan “ But the rate of output thereafter depends entirely on the ex- tent of the facilities devoted to production, which in turn could be geared to the amount of ores being made available for processing. The eminent Danish scientist, Niels Bohr, who was associated with the atomic bomb project, was reported as having stated publicly in October 1945 that the United States was producing three kilograms (6.6 pounds) of U+235 daily The amount of plutonium being concurrently produced might well be considerably larger. Dr. Harold C. Urey, also a leading figure in the bomb development, considers it not unreasonable to assume that with sufficient effort 10,000 bombs could be produced, #2 and other distinguished scientists have not hesitated to put the figure higher. considerably Thus, while the bomb may remain, for the next fifteen or twenty years at least, scarce enough to dictate to its would-be users a fairly rigorous selection of targets and means of delivery, it will not be scarce enough to spare any nation against which it is used from a destruction immeasurably more devastating than that endured by Germany in World lar II. It is of course tempting to leave to the physicist familiar with the bomb all speculation concerning its future increase in power. ul. 7 Time, October 15, 1945, p. 22. 2. New York Times, October 22, 1945, p. kl. However, the basic