Autograph letter card signed.
N. p. [Paris], 26. VI. 1924.
12mo. 1 p. With autograph address. Mounted on paper (4to).
€ 250,00
To the inventor and engineer Édouard Belin (1876-1933), congratulating him on the solution of a difficult problem: "Ce fut pour moi un grand plaisir de voir comment vous étiez parvenu à résoudre un problème passionnant et bien difficile. Je ne doute pas que vous continuerez à progresser dans le merveilleux".
As a pioneer of wireless telegraphy and radio transmission, Branly was an important predecessor to Belin, who invented the Bélinographe, the first phototelegraphic device.
Ink very slightly faded.
