Thèses présentées a la Faculté des Sciences de Paris pour obtenir le grade de docteur ès sciences physiques
Georges Sagnac's doctoral theses on X-rays, secondary radiation and cathode rays, printed in Paris by Gauthier-Villars in 1900 for the Faculty of Sciences and a readership of physicists. The plates are line-engraved optical diagrams: solid and dashed ray paths with arrowheads, hatched metal plates and prisms, screens drawn as double rules, and italic letter labels on tinted paper.
