John Loudon McAdam, Scottish engineer (died 1836)

John Loudon McAdam was a Scottish civil engineer and road-builder. He invented a new process, "macadamisation", for building roads with a smooth hard surface, using controlled materials of mixed particle size and predetermined structure, that would be more durable and less muddy than soil-based tracks.

September 23 is the 266th day of the year in the Gregorian calendar; 99 days remain until the end of the year.