PERROTIN, HENRI JOSEPH ANASTASE

(b St. Loup, Tarn-et-Garonne, France, 19 December 1845; d Nice, France, 29 February 1904)

astronomy.

Perrotin was the son of an employee in the telegraph service. His scholastic ability earned him scholarships to the lycé at Pau adn the Faculteé des Sciences of Toulouse. His professor at the latter, F. Tisserand, invited him to work at the Toulouse observatory (of which he was the director); and in 1873 he appointed Perrotin astronomer there.

During his career Perrotin made many observations, both astrometric(double stars, planets satellites, asteroids comets) and astrophysical (sunpots, study of plantely surfaces). He discovered five asteroids between 1874 and 1878 a sixth in 1885. Perrotin turned to celestial mechanics and in his doctoral dissertation established the first precise theory of the asteroid Vesta (1879). In this work he expanded the perturbing function as far as the eighth order relative to the eccentricites and inclinations, an achievement that has been applied by astronomers to verify recent theories of Vesta.

In 1879 Perrotin was engaged by Raphaël Bischoffsheim, the banker who built the Nice observatory, to become director of the observatory and to install its equipment. Perrotin devoted himself to this task until his death. The most important of the instruments that he put into service was the seventy-six-centimeter refractor (1886), which was then the world's largest. An inspiring leader of men, he obtained a great deal from his collatborators; and the first years of the observatory were marked by important projects, notably in spectroscopy and work on the asteroids. Perrotin’s measurements of the speed of light were based on the slotted-wheel method applied ti beams sent between the observatory and surrounding hilltops. The value of 299,880 kilometers per second, obtained in 1902 utilizing a combined trajectory of ninety-two kilometers, was considered the best estimate for more than thirty years.

In 1892 Perrotin was elected a corresponding member of the Académie des Sciences, which had twice awarded him a prize; and in 1894 he became a corresponding member of the Bureau des Longitudes.

BIBLIOGRAPHY

I. Original Works. Perrotin’s most important papers are “Théorie de Vasta,” in Annales de l’Observatioire astronomique magnétique et météorologique de Toulouse, 1 (1880), Bl-B90, also in Annales de l’Obervator’s Nice, 3 (1890), B1–B118, and 4 (1895), A3–A71; “Détermination des différences de longitudes entre Nice, l’lle Rousse et Ajaccio,” Annales de l “Observatorie de Nice8 (1904), 3–242, written with P. Hatta and L. Driencourt; and “Determination de la vitesse de la lumiere … ,” ibid., 11 (1908), A3–A98, written with A. Prim.

Perrotin published his astronomical observations, princupally in about fifty “Notes,” in Comptes rendus … de l’ Academie des sciences from 1875 to 1903 and, between 1875 and 1889, in Astronomische Nachricheten Also worthy of mention is “Parallaxe solaire déduite des observations d’Eros,” in Bulletin astronomique 20 (1903), 161–165.

Perrotin founded the Anates afe l’Observatore de Nice directed the publication of the first 10vols., and wrote several of them; among the latter are 2 (1887), devoted to various of his astronomical works, and “Description de l’Observatoire de Nice,” in 1 (1899), 1–152, with a view toward the establishment of the Nice observatory, Perrotin made an extensive inquiry, the main findings of which he published in Visite a divers observatories d’Europe (Paris, 1881) which describes the equipment of 31 European observatories.

II. Secondary Literature. The most important obituary notices are the unsigned “Todes-Anzeige,” in Astronomische Nachricten165 (1904), 254–255; and “M. Henri Perrotin,” in Nature, 69 (1904), 468; and E. Stephan, “J. A. Perrotin,” in Annales de l’Observatiore de Nice 8(1904), i–iv.

Jacques R. LÉvy