Édouard BRANLY, Physicist, He imagined in 1890 the cohearer - Lot 560

Lot 560
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100 - 120 EUR
Édouard BRANLY, Physicist, He imagined in 1890 the cohearer - Lot 560
Édouard BRANLY, Physicist, He imagined in 1890 the cohearer with filings first detector of hertzian waves which was used by MARCONI in his experiments of wireless telegraph etc.. (Amiens 1844 - Paris 1940) - Autograph letter signed on his letterhead "Laureate of the Institute", Sept 19, 1905. 1p 1/2 in-8° (on the same side). "Sir, I am very annoyed to be forced to refuse a second time, but, I have works started that I would like to finish before the Catholic Institute closes its doors. That is why it is absolutely impossible for me to be absent. I had to stay in Paris for the whole holiday..."
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