‎SAGNAC (G.)‎
‎De l'optique des RAYONS DE RÖNTGEN et des rayons secondaires qui en dérivent -- EDITION ORIGINALE -- ENVOI de G. SAGNAC à son camarade GUSSON‎

‎P., Gauthier-Villars, 1900, un volume in 8, broché, couverture imprimée, (défraichie avec manque de papier dans la partie supérieure du premier plat de couverture et dans l'angle inférieur du second plat, petite déchirure sans gravité dans la marge extérieure du titre, faux-titre remonté sur un onglet), (2), 166pp., figures dans le texte‎

Reference : 4627

‎---- EDITION ORIGINALE ---- ENVOI de G. SAGNAC à son camarade GUSSON ainsi libellé : "A mon camarade GUSSON ; Bien cordialement - G. SAGNAC" ---- "Sagnac studied mainly the radiation produced by X rays and the optics of interference. He is remembered today primarily for his design of a rotating interferometer and for the experimental results it provided. He was very interested in the theoretical analysis of optics of moving systems ; his approach was classical and he interpreted the results of his optical experiments as contradicting Einstein's theory of relativity... Sagnac's earliest research (and the subject of his dissertation) was motivated by the newly observed X rays. From 1896, the year following Röntgen's discovery, to 1900 Sagnac studied the radiations produced by X rays. He observed that secondary radiation is produced when X rays fall on heavier metals. He showed that this radiation contained secondary X rays (of lower frequency than the original X rays) and negatively charged rays. He suggested that it was through the action of the negative rays that X rays produce ionization in air". (DSB XII pp. 69/70) ---- Cf. Glasser pp. 328, 465 & 466**4627/B6DE‎