Michael Rodd learnt about a computer machine that detects forgery. The device, designed as a writing pad, makes it possible for a computer to feel the way a signature is being committed to paper, and recognises the differences in it's unique timings. Clip taken from Tomorrow's World, originally broadcast on Tuesday 18 April, 1972. You have now entered the BBC Archive, a time machine that will transport you back to the golden age of TV to educate, entertain and enlighten you with classic clips from the BBC vaults. Make sure you subscribe so that you never miss a single stop on our amazing journey through the BBC Archive - null