Abstract
PIERRE BOUGUER was born at Croisic in 1698. At an early age he was initiated in mathematics and problems of navigation by his father, who was one of the best hydrographers of his time. When only fifteen years of age he occupied the chair of his father, who had just died, and afterwards distinguished himself by his researches in physics, astronomy, and navigation. He is remembered to-day principally by his work on photometry, and by his expedition to Peru in 1735 to carry out a measurement of a degree of latitude, thus contributing to the solution of the important problem of the figure of the earth. It was during this expedition that he obtained an estimate of the mean density of the earth from pendulum observations in the neighbourhood of Chimborazo. The present essay, in which he laid down the fundamental bases of the science of photometry, is reproduced from the original text of 1729. The author discusses methods of measuring the intensity of light, the manner in which the intensity is changed by reflection or by absorption, and explains how to calculate the diminution in the intensity after the light has passed through various thicknesses of the absorbing medium. His work is distinguished by its clarity and the masterly realisation of the essential points in the problem to be solved.
Essai d'optique sur la gradation de la lumière.
Par Pierre Bouguer. (Collection “Les Maîtres de la Pensée scientifique.” ) Pp. xx + 130. (Paris: Gauthier-Villars et Cie, 1921.) 3 francs.
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Essai d'optique sur la gradation de la lumière. Nature 111, 320 (1923). https://doi.org/10.1038/111320b0
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DOI: https://doi.org/10.1038/111320b0