Overview: Tonight's stories of pioneering scientists and inventors come from Northern Ireland. Host Adam Hart-Davis discovers that the pneumatic tyre, invented by Belfast vet John Boyd Dunlop, began life as a remedy for his son's sore bottom. He also finds out how the name Harry Ferguson became synonymous with the development of the tractor. Taking his bike underwater, Hart-Davis goes in search of the origins of the submarine and wet suit. And, in Armagh, he learns how a child poet and astronomer rocketed to fame.