When drivers line up on the grid at the British Grand Prix on July 6th, they will be marking 75 years since the launch of the Formula One (F1) World Championship. Much has changed since the race in 1950 at the Silverstone circuit, which straddles Northamptonshire and Buckinghamshire. Then, the cars were basic, safety precautions rudimentary (ropes separated the track from the crowds) and the competitors included a Thai prince, a Swiss baron and a jazz musician.