Evans steam power demonstration. Illustration of 'Christmas Crackers' in December 1773 in a blacksmith's forge in the USA, inspiring the 17-year-old future US inventor and engineer Oliver Evans (1755-1819). A stoppered gun barrel containing water was heated, causing steam to eject the stopper with a loud report like a firecracker. This demonstration of the power of steam inspired Evans to apply it to the design of high-pressure, rather than low-pressure steam engines. Artwork from 'Chaudieres et Machines a Vapeur' (1911) by French civil engineer Max de Nansouty (1854-1913), part of the 'Les merveilles de la science' series of 1867-1891 by Louis Figuier.