Aveling and Porter 'road roller', 1867.

Engraving taken from the 'Illustratred London News'. Traction engines are mobile steam-powered road vehicles which can be used for haulage, agricultural purposes, or as a mobile power source. Thomas Aveling, a Kentish farmer, is widely recognised as the father of the mobile traction engine as, disatisfied with using horse power to move engines from place to place, he devised and built self-propelled steam engines at Rochester, Kent. He became a major manufacturer of the machines, specialising in steam road rollers, which were exported all over the world. Aveling and Porter continued to build traction engines until World War II.