Who invented the steam engine? Heron from Egypt. Heron lived in Alexandria and is best known as a mathematician and geometer. Unfortunately for Heron, no one was able to see its practical function, so it was considered nothing more than an amusing novelty. Amazingly, had Heron but known it, the railway had already been invented 700 years earlier.

The principle of railways was then completely forgotten about for almost another 500 years, until people had the idea of using them in mines in the fourteenth century. The historian Arnold Toynbee wrote a brilliant essay speculating what would have happened if the two inventions had been combined to create a global Greek empire, based on a fast rail network. Heron also invented the vending machine  — for four drachmas you got a shot of holy water  — and a portable device to ensure that no one else could drink the wine you brought along to a bottle party.