In October 1887, John Boyd Dunlop developed the first practical pneumatic or inflatable tyre for his son's tricycle and, using his knowledge and experience with rubber, in the yard of his home in Belfast fitted it to a wooden disc 96 centimetres across. The tyre was an inflated tube of sheet rubber. He then took his wheel and a metal wheel from his son's tricycle and rolled both across the yard together. The metal wheel stopped rolling but the pneumatic continued until it hit a gatepost and rebounded. Dunlop then put pneumatics on both rear wheels of the tricycle. That too rolled better, and Dunlop moved on to larger tyres for a bicycle "with even more startling results." He tested that in Cherryvale sports ground, South Belfast, and a patent was granted on 7 December 1888. Unknown to Dunlop another Scot, Robert William Thomson from Stonehaven, had patented a pneumatic tyre in 1847.