As radio signalling and broadcasting developed, attention was more and more directed to noise, that is to say unwanted disturbances. Some were shown to come from electric motors and dynamos, others from thunderstorms. On January 29th 1948, the Royal Society held a meeting at which Ryle and Vonberg, of Cambridge, communicated their results on accurate measurements, while Martyn, an Australian, produced a mathematical theory of the origin of the waves. Newton showed that the tides were due to the gravitational attraction of the moon and sun. Later Pallen gave the first accurate account of meteorites, objects from outside the air. The world is full of queer things, but they are not a bit like what our ancestors imagined. For example some viruses, such as that of lethargic encephalitis, can make good children into bad ones, as devils were supposed to do. But devils were pictured as like men, though excelling them in power and wickedness.