162 - BREGUET, Antoine (1851–1882), French physicist and inventor, great-grandson of the watchmaker and physicist Abraham Breguet

BREGUET, Antoine (1851–1882), French physicist and inventor, great-grandson of the watchmaker and physicist Abraham Breguet An exceptional collection containing Antoine Breguet’s archives for the years 1874 through 1880. It includes carbon copies of letters and scientific texts written by Antoine Breguet. Approximately 300 pp., in-4 format. Numerous signatures, mechanical and scientific diagrams and sketches, and mathematical calculations. A fascinating collection of Breguet’s correspondence regarding his inventions: the telegraph and the telephone. Notably included are texts concerning the creation of his mercury telephone (presented to the Academy of Sciences in 1878), his capillary telegraph device and its application to the telephone and to the devices of Bell and Edison, etc., accompanied by descriptive texts and supporting drawings. Patent filed with Brandon and Morgan Brown on Rue Lafitte, along with various amendments to this patent. “New amendment. I also claim the idea of maintaining, by means of a metal rod and through capillarity, a small column of liquid raised above the average level of that liquid. When the current flowing through the circuit of the rod and the liquid changes in intensity, the height of the raised liquid column changes, so that if a small spring causes the metal rod to separate from the liquid, the rod will oscillate vertically in response to variations in current intensity. I claim the application of the movements of this rod described above to telephony and telegraphy. I reserve the right to replace the metal rod with a graphite rod […]” (1878); Cornelius Roosevelt; Gabriel Lippmann, etc. Description of a telegraphic device designed to reproduce handwriting and characters remotely and continuously. Notes on Zénobe Gramme’s machine (direct current electric generator—theory, sketches, and machines of this kind, etc.); lecture on electrical energy, etc. There are also numerous scientific letters (to Gaston Tissandier, Léon Léonard Lavallée, Edmond Becquerel, etc.) and calculations and equations (gravity, vital forces). Index of names at the end. Valuable scientific sources on Antoine Breguet’s inventions, including numerous documents, some of which had been lost until now.