https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13995002
Telegram sent by G. Marconi in Wimereux to Édouard Branly in Paris, acknowledging Branly's work in developing the electric telegraph across the Channel. Photograph, ca. 1899.
Original public domain image from Wellcome Collection
Public DomainFree CC0 image for Personal and Business use