Einstein Fridge Comes in From the Cold

He is best known as the past century's most famous genius. But as well as devising the theory of relativity, Albert Einstein was also responsible, it emerged yesterday, for a less celebrated discovery - a fridge.

Nearly 80 years after he invented it, a group of German physicists have begun making Einstein's unique alcohol-powered fridge.

The existence of the fridge shows that the great scientist was not only a theoretician but also a down-to-earth practical inventor.

Jürgen Renn, director of the Max-Plank Institute in Berlin, said: "He came from a merchant family, he had to worry about money, and he was supposed to take over the family business."

Einstein wrote his theory of relativity in 1905, while working in the Swiss patent office. It was not until 1926, when he was living in Berlin and had won the Nobel prize, that he came up with his fridge.

He invented it after reading a news report about how an ordinary fridge had poisoned a sleeping Berlin family. Its pump had leaked sulphur dioxide.

Together with his fellow physicist Leo Szilard, Einstein built a fridge that used harmless alcohol gas.

Although Einstein took the trouble to patent his design, new technology meant his model never went into production. The only prototype built vanished. Only a handful of photographs exist.

The historian Peter Galison told the German science magazine ZeitWissen yesterday: "As a young man Einstein corresponded with friends about helicopters and measuring equipment, tinkered with small experiments, and filed patents."

Germany is gearing up for a double Einstein celebration next year. Events are planned to mark the centenary of his theory of relativity and the 50th anniversary of his death.