Towards the end of the 18th and the first years of the 19th centuries the processes of adiabatic expansion and compression of gases were studied by John Dalton (1766-1844) and Joseph Louis Gay-Lussac (1778-1850), who some consider the inventor of the pneumatic lighter; but the phenomenon was discovered by chance in 1802 by a worker in a St. Etienne arms factory who observed that a thread of linen in the barrel of a compressed-air gun had caught fire after the gun was shot. The discovery was announced to the Académie in Lyon on 20 December of the same year by Joseph Mollet, a professor of physics at the Ecole Centrale in Lyon, and commercial production of pneumatic lighters began in 1805 in the Paris factory of the Dumotiez brothers. Both in the metal and glass versions, the lighter was used for demonstrative purposes throughout the 19th and in the first half of the 20th centuries.
It is interesting to observe that in inventing his engine, Rudolph Christian Karl Diesel (1858-1913), the first of which was assembled in 1897, was inspired by a lecture on and demonstration of the pneumatic lighter that he had witnessed.
The Diesel engine is an internal combustion engine in which ignition is not caused by an electrically produced spark, but takes place spontaneously when the liquid fuel is injected in an atomized state into the cylinder by effect of the high temperature reached by the air contained in it in a previous compression phase.