After
the 14 July 1837 Act was implemented on 1 January 1840, declaring that the
decimal metric system was from now on the only legal system in France, the
French government applied to promote this system to foreign countries, and
therefore to bring it into general use.
In
this spirit in November 1841, the Minister for Trade suggested to the
countries that had trade relations with France exchanging collections of
length, capacity and weight standards. It was to concern the United Kingdom,
Russia, Netherlands and the states of Germany and Italy. Then, it was
planned establishing comparison tables between French and foreign weights
and measures.
The
French ambassadors in these countries were entrusted with offering exchanges
in December.
Fourteen
countries agreed and sent their standards to Paris in the following years:
Bade, Brunswick, Hamburg, Hannover, Hesse-Cassel, Lubeck, Lucques, Norway,
Prussia, Roma, Russia, Sweden, Tuscany, Wurtemberg.
Another
four agreed to the proposal but said they would postpone their sending until
they received the French standards. These states are Bavaria, Breme,
Hesse-Darmstadt, Sardinia.
The
French collections - metre, litre and kilogramme - were ordered to Gambay, a
manufacturer of mathematics instruments, since the mid-1842. However, his
workshop suffered a lot of difficulties. Besides, Gambey had to develop a
comparator and a set of scales to check - with the accuracy required - the
metres (at 0.001 mm) and the kilogrammes (at 0.5 mg). Thus, the collections
were ready and sent to the eighteen above-mentionned countries only in
October 1847.
The
sending consisted of the three brass-made standards put in a mahogany
lockable box, plus a calibration certificate, an official book of legal
texts and directives and an issue of "l'Atlas des poids et mesures" - the
Atlas of weights and measures.
A
little later, the School of Technology and Engineering prepared other
similar collections. It seems that it sent specimens of these collections to
these countries: the United-Kingdom, Austria, Spain, the United-States,
Japan, Portugal, Mexico, New-Granada (Colombia), Venezuela.
Besides
the fourteen above-mentionned countries, the only countries which sent to
France its collections of length, capacity and weight measure standards are
the United-Kingdom, Spain, and the United-States. These objects were
received in Paris between 1850 and 1855.