Maglev (magnetic levitation) trains are elegant and audacious works of engineering that operate by harnessing the power of magnetic repulsion and electromagnetism to move traincars that quite literally float above the track – today, often at speeds of hundreds of miles per hour. In this lecture at Imperial College London from 1975, the British engineer and professor Eric Laithwaite (1921-97) deconstructs the fascinating physics at work behind his plans for a maglev train, which he first modelled in 1940s and perfected in the 1970s. Well-regarded in his time as both a lecturer and an engineer, Laithwaite presents a series of demonstrations that build, step by step, until he finally unveils a small maglev train model. The first commercial maglev train debuted at Birmingham Airport in 1984, and today Laithwaite’s engineering breakthroughs help power many of the world’s fastest trains.