Paris Imprimerie Gauthier-Villars et fils s.d. [1891] in-8 broché
Reference : 25958
40 pp.Rare extrait de l'Annuaire du bureau des longitudes. Le polytechnicien Alfred Cornu (1841-1902) est surtout connu pour ses travaux sur la diffraction de la lumière. Il reprit et développa l'expérience de la roue dentée d'Hippolyte Fizeau portant sur la mesure de la vitesse de la lumière, en introduisant un dispositif électrique d'enregistrement de la vitesse de rotation de la roue ; ses trois expériences successives (1872, 1874) permirent d'affiner les résultats obtenus par Fizeau.Un seul exemplaire au CCFr (Observatoire)
Librairie Chamonal
Rodolphe Chamonal
5 rue Drouot
75009 Paris
France
01 47 70 84 87
conformes aux usages du Syndicat de la Librairie Ancienne te Moderne et aux règlements de la Ligue International de la Librairie Ancienne
P., Bureau des Longitudes, 1891-1902, un fort volume in 8 relié en demi-chagrin rouge (reliure de l'époque)
---- TRES RARE REUNION DE MEMOIRES ORIGINAUX DE A. CORNU ---- ENVOI DE A. CORNU A SON CAMARADE GENTY ainsi libellé : "Au Camarade GENTY - Souvenir amical - signé cornu" ---- BEL EXEMPLAIRE ---- "A series of experiments dating from 1871 led to a redetermination of the velocity of light by Fizeau's method, for which Cornu was awarded the La Caze Prize and the Rumford Medal. Cornu made a number of important contributions to spectrum analysis including very precise measurements of the wavelenghts of certain lines in the hydrogen spectrum. By observing the dges of the solar disk and applying the Doppler-Fizeau principle, he found a means of separating the solar spectra from the terrestrial spectra ; in the case of the latter he separated the influence of water vapor from that of air. Following the discovery of the Zeeman effect Cornu showed that the D line of sodium is decomposed, under normal magnetization, into four components, as opposed to three, thus forcing Lorentz to modify his theory of the Zeeman effect. Cornu's optical researches also included studies of conditionsfor achromatism in interference phenomena ; his work on measurement of the curvature of lenses ; and his explanation of vertain observed anomalies in the behavior of diffraction gratings in terms of minute variations in the distance between successive lines... Cornu is remembered for the elegant method of the so-called Cornu spiral for the determination of intensities in interference phenomena". (DSB III)**5956/M2