How the pneumatic tyre became a million dollar idea

We can thank Alfred Dunlop for giving us an easy ride on our bikes and in our cars. He brought out the modern pneumatic - or air-filled - tyre. It caught on like wildfire amongst cyclists and motorists at the end of the 19th Century. But spare a thought for fellow Scotsman Robert Thomson, who invented it 50 years earlier, only to find no one wanted it yet. Aaron Heslehurst explains.

Video journalist: Jeremy Howell