The Pyréolophore (pronounced pea-ray-oh-loh-for; from Ancient Greek πῦρ, pyr, meaning 'fire', Αἴολος, Αiolos, meaning 'wind', and -φόρος -phoros, meaning 'bearer') was the world's first internal combustion engine. It was invented in the early 19th century in Chalon-sur-Saône, France, by the Niépce brothers: Nicéphore (who went on to invent photography) and Claude.
In 1807 the brothers ran a prototype internal combustion engine, and on 20 July 1807 a patent was granted by Napoleon Bonaparte after it had successfully powered a boat upstream on the river Saône.
The Pyréolophore ran on what were believed to be "controlled dust explosions" of various experimental fuels, although technically they were deflagrations (rapid burns). The fuels included mixtures of Lycopodium powder (the spores of Lycopodium, or clubmoss), finely crushed coal dust, and resin.
Operating independently, in 1807 the Swiss engineer François Isaac de Rivaz built the De Rivaz engine, a hydrogen-powered internal combustion engine. These practical engineering projects may have followed the 1680 theoretical design of an internal combustion engine by the Dutch scientist Christiaan Huygens. The separate, virtually contemporaneous implementations of this design in different modes of transport means that the de Rivaz engine may be correctly described as the first use of an internal combustion engine in an automobile (1808), whilst the Pyréolophore was the first use of an internal combustion engine in a boat (1807).
The Niépce brothers were living in Nice when they began their project to create an engine based on the newly defined principle of hot air expanding during an explosion. The challenge was to find a way to harness the energy released in a series of explosions.