The metre, equal to the ten millionth part of a quarter of the terrestrial meridian, the distance from the Pole to the Equator, as a universal and invariable measure, reproducible and verifiable everywhere and always, was introduced in France in 1795 by the National Convention of the French Republic.
First attempts to introduce the metric system in the Este Duchy
In Modena at the end of the 18th century, the subject remained confined to academic circles, despite the urgings of Giovanni Battista Venturi (1746-1822), a physics lecturer at the University. When the French arrived in Modena in 1796, Venturi moved to Paris and sent to Modena the sample metre, which had been made by Etienne Lenoir for the Physics Cabinet on the first floor of the eighteenth-century University Palace Palazzo, today the seat of the Rectorate.
In northern Italy during the Napoleonic era, the Italian Republic, proclaimed in 1802, introduced the decimal metric system with a law of 27 October 1803. After the fall of Napoleon in 1814, the previous governments were re-established and the old measures were readmitted: only the decrees for the verification of weights and measures remained in force.
After the Restoration of the old sovereigns in the Italian States, during the period of sovereignty of Archduke Franz IV of Austria Este (1779-1846, Archduke from 1814), the weights and measures legally in use in the Duchy of Este continued to be used from 1814 to 1846.
First ducal legislation to introduce the metric system
In 1849, his son and successor, Franz V (1819-1875, Archduke from 1846) issued a decree stating that from 1852, the decimal metric system would be definitively introduced in the Este Duchy in order to standardise the measurements that still differed from one locality to another. The reform stemmed from the desire to promote the development of trade with other Italian states, especially with the French-Piedmontese axis, where the metric system had already been adopted, and with Austria, where it was considered imminent. The intention was to put an end to the chaotic coexistence of the innumerable weights and measures of the Este Dukedom in order to facilitate commercial transactions.
The Special Commission on Weights and Measures
To make the new metrological system effective, Count Ferdinando Castellani Tarabini, the Este Duchy’s Finance Minister, appointed a special Commission on Weights and Measures to draw up regulations for the production of samples of the metric system, and oversee their manufacture. It was made up by two professors from the University of Modena, Stefano Marianini (1790-1866), president of the Italian Society of Sciences, based in Modena, and Giuseppe Bianchi (1791-1866), director of the Astronomical Observatory and secretary of the same Society. In order to start these operations, the Commission should have obtained copies of the metre and kilogram samples made in France.
Making metric samples in Paris
For the realization of the samples of the metric system, Marianini made contact in Paris with Jean Baptiste Biot (1774-1862), physicist and mathematician, member of the Italian Society of Sciences, who wanted him to be assisted by Henry Victor Regnault (1810-1878), physicist and professor at the College of France, a great connoisseur of the most accurate instruments and techniques in the field of metrology. Biot suggested the manufacture of a brass rather than platinum standard metre, a dial gauge for linear measurements and a straight-line dividing machine entrusted to Louis Guillaume Perreaux (1816-1889), a mechanical engineer. Biot also proposed that the task of making a sample kilogram and a precision balance be assigned to the optician Louis Joseph Deleuil (1765-1862).
In order to relieve the French technicians and Biot of all responsibility for verifying the new instruments with those kept in Paris in the National Archives, Giuseppe Bianchi was sent to Paris in August 1850. Together with Biot, Perreaux, Deleuil and Regnault, he carried out the comparisons at the Paris Observatory.
The arrival of samples in Modena and the creation of the Metrology Laboratory
On 18 January 1851, the instruments made in Paris arrived in Modena from Livorno after a long journey through France. In a letter dated 31 January 1851, Bianchi announced to Biot that the Special Commission on Weights and Measures had begun work with the new instruments in the Metrology Laboratory. The latter had been set up in the Ducal Palace in a flat adjacent to the Astronomical Observatory located in the east tower. In February 1852, thanks to Bianchi’s intervention, Cesare Zoboli, who was already in charge of the Observatory’s mechanical laboratory, was appointed “inspector and mechanic of the Weights and Measures Office”.
The creation of the Metric Workshop for making samples
In the same year, a set of regulations was published, but the tables were missing because the sending of samples by the communities of the Duchy was slow and difficult. For this reason, it was decided to postpone the entry into force of the metric system to 1 January 1853 and it was also decided that the complete set, which the 72 Communities of the Este Duchy should have, consisted of 13 weight and measurement instruments based on multiples and submultiples of the metre and kilogram.
The creation of the Metric Workshop for making samples
On 1st January 1856, Zoboli was commissioned to manufacture the samples and it was decided to set up a Metric Workshop in a building in the eastern part of the city, which two centuries earlier had been used as stables by Duchess Laura Martinozzi (1639-1687), regent of the Este Duchy from 1662 to 1674 after the death of her husband, Duke Alfonso IV d’Este (1634-1662, duke from 1658). The famous Modenese architect Cesare Costa made the architectural survey and the Weights and Measures Workshop was opened on 1st June 1856, despite the fact that the installation of the instruments had not yet been completed.
The introduction of the metric system was postponed until 1st of January 1857, but in the first months of 1857 all the samples to be sent to the Communities had not yet been completed due to the lack of equipment and specialised personnel in the Workshop.
By the beginning of December 1857, only 14 Communities had received the complete set of weights and measures, six of which had not yet paid.
The closure of the Metric Workshop and the dissolution of the Weights and Measures Commission
In February 1858, as the General Treasurer of the Ministry of Finance of the Este Duchy testifies, the activities of the Metric Workshop had been greatly reduced, and the Special Commission for Weights and Measures was also dissolved. Shortly afterwards, on 17 March 1858, the Metric Workshop was finally closed down by Franz V.
The fame of the Metric Wokshop
The Metric Workshop’s activities had, however, gained a good reputation. Angelo Secchi (1818-1878) from Reggio Emilia, director of the Observatory of the Collegio Romano in Rome, had already asked Bianchi to carry out a test with a copy of the Perreaux meter made by the Modenese Metric Workshop for measurements along the Via Appia from the monument of Cecilia Metella (Rome) to the tower at Frattocchie (Marino). In 1857 Secchi commissioned the Metric Workshop of Modena to make a double decimeter, and in 1858 he received as a gift a set of metric samples made by Zoboli to be used as sample instruments for measurements in the Observatory of the Collegio Romano.
A video Measuring in metres was made with a text of the present authors in collaboration with Massimiliano Venturelli and Giorgia Gavanelli Association Save Italian Beauty. The video, with photos of Vincenzo Negro, was edited by Enrico Montanari. It was presented on the occasion of the 20th “Settimana della didattica e dell’educazione al patrimonio in archivio” (Week of didactics and heritage education in archives), organised by the Cultural Heritage Service of the Emilia Romagna Region as part of the annual meeting “Quante storie nella storia”.