Valentine: Low railroad

Going underground on London's Tube network is rendered much easier by the use of escalators; but so sceptical were the capital's travellers when moving staircases were first introduced that London Transport was obliged to employ a one-legged man, "Bumper" Harris, to ride up and down all day, to convince the public of the devices' safety.

On 18 March, at the London Transport Museum (0171-379 6344), Mark Dennison, the curator, will be discussing innovation in a talk entitled "It'll never work" (which, in the case of the ill-fated spiral escalator, seems appropriate). He will also reveal how fish were, for a time, transported on the Circle Line - though escalators were never used as impromptu salmon leaps.

The event begins at 6.30pm, and tickets cost pounds 6 (pounds 4 conc).