What year did John McAdam invent tarmac?

Tarmac was first invented by John MacAdam. got it?

Not True: John MacAdam came up with the idea of using graded stone to pave a road.

It was Edgar Purnal Hooley who when passing a works noticed that where a pot of tar had been spilled and stone scattered over to soak it up, there was a tight bound surface with no dust. He went on to develop tar-macadam and the company he formed went on to be the company we know as Tarmac today.