John McAdam
John McAdam, (1756-1836). Scottish inventor. He experimented with road construction in Ayreshire, Cornwall, and Bristol and developed a method that used a raised core of large rocks with drainage ditches at each side, covered with a surface of small stones bound with gravel. This technique, called ‘macadamizing’ after its inventor, has been widely adopted. Tar or asphalt is used to bind and smooth the surface in modern road-making. McAdam became surveyor-general of roads in 1827.
