I cannot tell you which happened earlier, whether this conversation with Szilárd or my attendance to an American Association of Physicists, where the great nuclear physicist, Lord Rutherford, was talking. It was a remarkable talk. In a way it was boring. Lord Rutherford said- There are some people who think that nuclear energy can be released. They are complete fools. It is so hard to get nuclei close to each other, this will never happen. Now, I'm sorry, I cannot repeat to you what Rutherford said, because Rutherford, using different words, repeated that long enough to take twenty or twenty-five minutes. He talked of practically nothing else. And then I saw Szilárd and I knew - I got up from him - that the fool who thought that this could be done was none other than Leó Szilárd and this rejection by Rutherford annoyed him to a point that he took out a patent on it. The special way he wanted to do it happened to be wrong. I already told you that at that time atomic weights and atomic energies were not known very accurately. One of the light atoms, beryllium - the fourth in the periodic table, hydrogen, helium, lithium, beryllium - had - normal beryllium, beryllium 9 - had four protons and five neutrons and the last neutron was bound so lightly that Szilárd thought it was not bound at all energetically; just stayed there for some unknown reason. And beryllium was the obvious donor of neutrons. He made experiments on it and found it didn't work. Then he heard about uranium fission. He came down to Washington and told me what now is obvious. Here, we have fission in uranium. If, in the process where uranium splits into two, if there is not only a neutron absorbed, but at the end more than one neutron emitted, then we could have the chain reaction. One neutron in, maybe two out, then those being absorbed giving four and then eight and then sixteen and after ten steps a thousand, and after twenty steps, a million. And after fifty steps, enough to turn most of the nuclei- most of the energy, in a chunk of material into actual explosion, explosive. And that is what should be done. But nobody knows whether actually these neutrons, these additional neutrons, are emitted. That was the very end of January 1939. The discovery in Germany happened a few weeks earlier.