Pierre Hugon is mainly known through his contribution to the early internal combustion engine, especially the "Hugon" engine, which was the second internal combustion engine to go into commercial production - and was a stationary engine along similar lines to the earlier "Lenoir" engine. According to various patents and other entries Pierre Hugon is variously described as a "Civil Engineer",[1] and also as "directeur de la Compagnie du Gaz de Paris". In 1866 the London Gazette[2] informs us that he is resident in Paris at 56 Rue de l'Orient, and in his US patent of 1874 he is still listed as a resident of Paris.