Arago, Francois Jean

Aiton's Encyclopedia (1910)

a'ra-go, Francois Jean (1786-1853), a French scientist. Though dead little over half a century, Arago is a marked example of the way in which eminent men and eminent services pass from the public mind. As a student, director of the Observatory of Paris, editor of the Annals of Chemistry and Physics, member of the Chamber of Deputies, Minister of War and Navy, professor in the Polytechnical School and secretary of the French Academy of Sciences, he was a brilliant, able, prominent figure for half a century. With the celebrated Biot he completed the measurements of a geographical meridian on which the scientific meter is based. Among his contributions to scientific knowledge are researches regarding the polar snows of Mars, the belts of Jupiter and Saturn, sunspots, the effects of atmospheric refraction, the oscillations of the magnetic needle , the connection between the aurora borealis and magnetism, the creation of a magnet by the use of the galvanic current, the polarization of light, the construction of a polariscope, the interference of colors, and the velocity and the wave theory of light. In the discharge of legislative and administrative duties to which he was called, Arago was influential in establishing public education, in the development of railroads and telegraphs, in improving the navigation of the Seine, and in the boring of artesian wells . He abolished flogging in the navy, and brought about the downfall of negro slavery in the French colonies. He was a brilliant writer, an eloquent speaker, a public spirited citizen, and, as we have seen, contributed in no small degree to the advancement of science. 2026 Editor's Note: This page uses language about race that was commonplace when the book was published and is offensive by today's standards. The text has been left exactly as it was printed, rather than cut or softened, so that the historical record — including how ordinary such language once was — is preserved. (Ed: BR 2026-07-22) 2026 Editor's Note: The entry's lament that Arago was forgotten proved half-wrong: physics still teaches the ' Arago spot ,' the bright dot at a shadow's center that helped prove light is a wave. And 135 bronze medallions bearing his name are set into the pavements of Paris along the old meridian — a hidden trail made famous by The Da Vinci Code . (Ed: BR 2026-07-09)