Justin Croft Antiquarian Books - Rare and Antiquarian Books and Manuscripts

First edition of an important practical guide to the new metric system, designed to counteract the persistence of local customary measurements in the regions of France and containing numerous tables for conversion from the old measures to the new. François Gattey was, with Legendre, one of the members of the convention established in 1795 to enact the definitive adoption of the metric system. “One of the most significant results of the French Revolution was the establishment of the metric system of weights and measures....On June 19, 1791, a committee of 12 mathematicians, geodesists, and physicists met with Louis XVI, who gave his formal approval. The next day, the king attempted to escape from France, was arrested, returned to Paris, and was imprisoned; a year later, from his cell, he issued the proclamation that directed two engineers, Jean Delambre and Pierre Méchain, to perform the operations necessary to determine the length of the metre. The intervening time had been spent by the scientists and engineers in preliminary research; Delambre and Méchain now set to work to measure the distance on the meridian from Barcelona, Spain, to Dunkirk in northern France. The survey proved arduous; civil and foreign war so hampered the operation that it was not completed for six years. While Delambre and Méchain were struggling in the field, administrative details were being worked out in Paris. In 1793 a provisional metre was constructed from geodetic data already available. In 1795 the firm decision was taken to enact adoption of the metric system for France. The new law defined the length, mass, and capacity standards and listed the prefixes for multiples and submultiples. With the formal presentation to the assembly of the standard metre, as determined by Delambre and Méchain, the metric system became a fact in June 1799. The motto adopted for the new system was ‘For all people, for all time’” (Ency. Brit.).