The question of priority

The first document attesting to the research activity of Barsanti and Matteucci on the possibility of obtaining mechanical energy from the explosion of a gaseous mixture is the paper that was deposited at the Accademia dei Georgofili on 5 June 1853. This document described the first experiments, carried out using simple apparatus consisting of hollow cylinders and pistons; indications were given on the possible developments of the research, but what is more important is that the opportunity of
“… use this return, and not the outward, to produce the desired useful effect by means of gears and mechanisms …”, or the concept of a motor with action delayed on the return stroke.

In 1860, in France, the mechanic Lenoir patented his direct-action internal combustion engine without precompression. In an internationally circulated article, Figuer presented the engine as a sensational innovation and Lenoir as the inventor of the gas engine. At the same time, also in France, the Abbé Migne defended, in the newspaper Le Monde, the priority of the Italian invention.
Following the outcry caused by the appearance of the Lenoir engine, the two Italians, to assert their ownership of the invention, deemed it useful to unseal the package deposited at the Accademia dei Georgofili in September 1863; it was probably for the same purpose that the Ximenian Manuscript was drawn up, which reconstructs the entire work of the two inventors.
Also in 1863, the so-called Bauer engine was built according to the English patent of 1857, which, following in-depth experiments, was awarded the silver medal and priority recognition over the Lenoir engine by the Royal Lombard Institute of Sciences, Letters and Arts.

The engine designed by Germans Otto and Langen appeared in 1867 at the Paris Universal Exhibition, where it won first prize. However, the engine designed by the two Germans was, except for a few minor details, nothing more than the version without an auxiliary piston, cited in the 1858 French patent, developed by the two Italians.

The analogy between the two engines was highlighted by many, including the Frenchman Durand, director of the Paris newspaper “Le Gaz”, who, in 1867, wrote: “… the gold medal that it (the Exhibition) awarded them was wrong in its purpose… At first glance, this device appeared to us to be nothing other than a poor imitation of the invention of Messrs. Barsanti and Matteucci, patented in France on 9 January 1858…”
Durand was kind enough to send a letter to Matteucci informing him of the developments. Matteucci immediately left for Paris, taking with him the designs of the engines he had built, to claim the invention's primacy. Unfortunately, his arguments were not taken into consideration. Matteucci attempted several more times over the years to assert his rights, without success.

The priority of the Italian invention was later recognized also by German historians, who remarked that Otto and Langen's machine could possibly be considered an improvement on the Italian machine.

In Italy, Senator Giuseppe Colombo published an article in the 1868 Italian Scientific Yearbook defending the priority of the Italian invention; in December 1931, the then director of the Osservatore Ximeniano gave a speech, presenting detailed documentation, to obtain official recognition of the invention, but to no avail.

In the early years of its activity, the Barsanti and Matteucci Foundation promoted numerous initiatives aimed at recognizing the priority of Barsanti and Matteucci's invention, starting with the collection of fundamental documents and their translation into English and German, so that they could be presented to the international scientific community and more easily demonstrated their theories.

On this basis, the Deutsches Museum in Munich was the first to recognize the Italians as the inventors and placed a plaque in the room dedicated to the internal combustion engine, stating that the first three-stroke internal combustion engine had been invented by Barsanti and Matteucci. Furthermore, since 2004, the model of the two-cylinder engine, built and donated by the Foundation, has been on display in the same museum. Finally, the two illustrious men from Lucca have been universally recognized as the inventors.

In 2025, after two years of study and patient work, a group of technicians belonging to the Florentine Vintage Motorcycle Club managed to reconstruct a engine according to the designs of Barsanti and Matteucci, fully functional.