Units of measurement in France before the French Revolution 4 parts in one million) than the "pied" used in France. According to the law of 19 Frimaire An VIII (December 10, 1799), Traditionally, the French pound ("livre") was defined as the mass of exactly of a French cubic foot of water. When the kilogram was defined, the knowledge that a "pied du Roi cube" filled with water masses exactly 70 French pounds was apparently lost. According to the traditional (cubic foot) definition, one "livre" would have been about 489.675 grams. According to the kilogramme definition, one "livre" was about 489.506 grammes. The difference is about 0.035%. However, a small
Pied-winged swallow Pied-winged swallow The pied-winged swallow ("Hirundo leucosoma") is a species of bird in the family Hirundinidae. It has distinctive steel-blue upperparts with white wing patches. It is native to parts of West Africa. The pied-winged swallow was described by the English ornithologist William Swainson in 1837 who introduced its current binomial name "Hirundo leucosoma". The specific epithet combines the Ancient Greek words "leukos", "white" and "sōma, sōmatos", "body". The species is monotypic. Evolutionarily, the pied-winged swallow occupies a basal position within the clade of "Hirundo" swallows and is most closely related to the pearl-breasted swallow ("Hirundo dimidiata"). The pied-winged swallow