Father Eugenio Barsanti – together with Felice Matteucci – was the inventor of the internal combustion engine; the photo above is of a model of the engine, currently on display in Florence.
Wikipedia drives home the details: “Father Eugenio Barsanti (12 October 1821 – 19 April 1864), also named Nicolò, was an Italian engineer, who together with Felice Matteucci of Florence invented the first version of the internal combustion engine in 1853. Their patent request was granted in London on June 12, 1854, and published in London’s Morning Journal under the tile “Specification of Eugene Barsanti and Felix Matteucci, Obtaining Motive Power by the Explosion of Gasses”, as documented by the Fondazione Barsanti e Matteucci,
Barsanti was born in Pietrasanta, Tuscany. Lean and short of stature, he studied in a Catholic scientific-oriented institute near Lucca, in Tuscany, and became a novitiate in Florencein 1838 of the Piarist Fathers or Scolopi, who were known for being open to scientific study.
In 1841 Barsanti began teaching in the Collegio San Michele, situated in Volterra. Here, during a lecture describing the explosion of mixed Hydrogen and air, he realised the potential for using the energy of the expansion of combusting gases within a motor.
Subsequently, when teaching in a college level institute in Florence he met Felice Matteucci, a hydraulic engineer. Matteucci appreciated the idea for the engine, and the two men worked together on it for the rest of their lives.
They patented their invention in London, on 12 June 1854 as Italian law at that time could not guarantee sufficient international protection on the patent. The construction of the prototype was later completed in the 1860s.
The main advantage of the Barsanti-Matteucci engine was the use of the return force of the piston due to the cooling of the gas. Other approaches based on the pushing force of the explosion, like the one developed by France’s Etienne Lenoir, were slower. The Barsanti-Matteucci engine was proven to be much more efficient, and won a silver medal from the institute of science of Lombardy.”
Read the rest of the Wikipedia article, linked here.