Report by Charles Fabry on Leroy's papers (1930). 2. Patent for the invention of a system of aplanetic objectives (December 28, 1891). 3. Various studies: electricity (G. Berson's notes), precision shooting, teleobjective, excentricity of divided circles, photometers, telescopic combinations, measurement of astigmatism, ophtalmometer. 4. Magnetism, batteries, resistance, galvanometer, telephone, lighting, Ruhmkoroff's coil, electro-optical phenomena. 5. Physical optics, achromatism, spectroscopy, stereoscopy, optometry, photometry. 6. Diffraction, objectives, melanochromoscopy, negative ocularity [eye-piece], spheric aberration.
