PIERRE

See also:

• PIERRE BOUGUER (1698-1758)

BOUGUER (1698-1758)  , French mathematician, was born on the 16th of February 1698 . His father, John Bouguer, one of the best hydrographers of his time, was regius professor of hydrography at Croisic in lower Brittany, and author of a treatise on navigation . In 1713 he was appointed to succeed his father as professor of hydrography . In 1727 he gained the prize given by the Academie des Sciences for his paper " On the best manner of forming and distributing the masts of ships "; and two other prizes, one for his dissertation " On the best method of observing the altitude of stars at sea," the other for his paper " On the best method of observing the variation of the compass at sea." These were published in the Prix de l' Academic des Sciences . In 1729 he published Essai d' optique sur la gradation de la lumiere, the object of which is to define the quantity of light lost by passing through a given extent of the atmosphere . He found the light of the sun to be 300 times more intense than that of the moon, and thus made some of the earliest measurements in photometry . In 1730 he was made professor of hydrography at Havre, and succeeded P . L . M. de Maupertuis as associate geometer of the Academic des Sciences . He also invented a heliometer, afterwards perfected by Fraunhofer . He was afterwards promoted in the Academy to the place of Maupertuis, and went to reside in Paris . In 1735 Bouguer sailed with C .

M. de la Condamine for

Peru, in order to measure a degree of the meridian near the equator . Ten years were spent in this operation, a full account of which was published by Bouguer in 1749, Figure de la terre determinee . His later writings were nearly all upon the theory of navigation . He died on the 15th of August 1758 . The following is a list of his principal works:—Traite d'optique sur la gradation de la lumiere (1729 and 176o) Entretiens sur la cause d'inclinaison des orbites des planetes (1734) ; Traite de navire, &c . (1746, 4to); La Figure de la terre determinee, &'c . (1749), 4to; Nouveau traite de navigation, contenant la theorie et la pratique du pilotage (1753); Solution des principaux problemes sur la manoeuvre des vaisseaux (1757); Operations faites pour la verification du degre du meridien entre Paris et Amiens, par Mess . Bouguer, Camus, Cassini et Pingre (1757) . See J . E . Montucla, Histoire des mathematiques (1802) .