How do you separate the wheat from the chaff? For thousands of years farmers had simply beaten their grain with sticks or ropes to knock the seeds from the stalks. But this was back-breaking work and to supply enough food for the country's rapidly growing population British farmers needed a better way to do it.

When Scottish millwright Andrew Meikle unveiled his prototype threshing machine in 1778, it was a failure. So was his second attempt a few years later. Meikle's prototype - and the machines that he had based it on - simply weren't beating the wheat in the same way that the workers did: they were tending to rub it, and that wasn't a very effective way to release the grain.

So Meikle had a rethink and constructed a strong drum with fixed wooden arms that beat the wheat rather than just rubbed it. It is believed that the drum that made Meikle's machine a success may have been copied from a "scutching" machine used to beat the fibres from flax plants.

Powered by a horse or a steam engine, his rotating drum design gave better results than other threshing machines. He took out a patent in 1788 and probably began manufacture a year later.

Although his threshing machine was eventually a huge success it received a stormy reception from farm workers. Like many labour-saving devices designed during the period, it wasn't welcomed by the workers whose livelihoods it threatened. In fact, the machine designed to beat grain was regularly on the receiving end of beatings meted out by mobs of angry workers. Things came to a head in 1830 in what became known as the Swing Riots, during which workers destroyed threshing machines and attacked farmers. It was too late, however, and Meikle's thresher soon became a common sight throughout the countryside.