And the meter was explained to people

 May 20, 1875 at the Ministry of Foreign Affairs in Paris, the Metre Convention was signed, the treaty by which a country agrees to adopt of the Metric Decimal System.

 Among the 16 signatory countries there is Italy, which with its scientists, from the mathematician Langrange to the astronomer father Secchi, had contributed to the construction of the system.

The king Carlo Alberto, shortly before leaving for exile in Oporto, had promulgated a law in which was established the date of 1 January 1850 for the formal introduction of the Metric Decimal System into the kingdom of Sardinia. The Metric Decimal System progressively was extended throughout Italy, after the consequences of the Ann exations and the wars of Risorgimento.

It was adopted by law, the most difficult task remained: the Metrological literacy of citizens.

In Piedmont this task was carried out with the Government's commitment, with a massive intervention of the church and with the "social saints" of Turin.

The names are the ones of San Giovanni Bosco who founded the Salesiani community, of the blessed Faá di Bruno (engineer, mathematician, academician, professor and priest), of Murialdo, of Cottolengo, of the canon Allamano and others.

The introduction of a metric system clashed with consolidated costumes and traditions, it couldn't just be entrusted to laws or fines, but a capillary, long and patient operation of education should have been done. The simple notion of a decimal system collided with millennia of tradition of measures linked by relation 2, 6, 12 and almost never 10. On the other hand we're still buying eggs in dozens!

The problem of metrological literacy should have been faced differently based on different cultural groups of the population: students and adults.

At first courses for teachers were organized, a particular text for professors was commissioned to the Brothers of the Christian School, boards were distributed and models of wooden or cardboard of champions and geometric solids were sent to all public schools of every grade and order.

The text of the Brothers of the Christian School is remarkable for two reasons, the first is the interesting and instructional preparation, in the sense that each chapter is equipped with questions that the teacher has to ask himself before teaching the single concepts, with other questions that have to be posed to the students; exercise's text are also suggested with answers included.  Another interesting characteristic is the fact that single concepts are systematically faced in three steps; it begins in one or two paragraphs and then goes back to the same concept for few pages. The second reason lies in the fact that in this 1849's text in the first chapters the story of the construction of the metric system appears, which is probably the most complete until now, it appeared in Italian language. To find the same news, sometimes we have to resort to fundamental texts of the history of metric system written in other languages.

It remained the problem of metrological literacy of adults, in absence of communication media like radio and television and in the presence of a strong component of illiterate.

The Ministry of Agriculture, through the Ministry of Interior, asked the United Diocese of Sardinia to send to the parish priests of over seven parishes of the Kingdom, a Metrology manual with an invitation to present the new system during the Sunday sermons. And so the meter was taught by all the pulpits of the Kingdom of Sardinia. Among the metrological education texts addressed to students of vocational schools, artisans and peasants, the book "The metric system reduced to simplicity preceded by the first four operations of arithmetic to use artisans and country people" is particulary interesting in care of the priest St. John Bosco, Salesians’s founder . The text, of 80 pages, was reprinted about 6 times between 1849 and 1872.

Don Bosco emphasizes that the purpose of this book  is reducing the metric system to the most simplicity: “to be more easily understood sometimes I ignored the features of mathematics language, and I cared about being intense and no more embellishment because are useless, maximum simplicity, effectiveness and to reach the intended purposes”. In Piedmont are still in use two unit of measure used before the introduction of the metric system by parish priests. Around 1850, the miria used as an abbreviation of Minagramma, used in the grapes and the stero  commerce, synonymous of metric cube, currently used in the trade of wood, straw and hay. On the other hand the prefix miria for 104, now obsolete doesn't desappear from scientific literature in French, English and Italian language; for example the band of eletromagnetic waves between 3 103 and 3 104 Hz, is called  miriametric band.


Edit by Giorgia Ciappa, Martina Guidotti, Ginevra Colturato, Bianca Baracco e Estella Colombo

Liceo Gioberti (Torino)

Progetto di Alternanza Scuola-Lavoro anno 2016-2017