Photographic painting by Auguste Couttet "crevasse passage end of the 19th century"

Photo on a board support by Mr Auguste Couttet: ascent of Mont Blanc in 1880, very good condition. It is an original since the photo is signed even if the process (photo9 board) was done at the end of the 70s (management of the heirs of Mr Auguste Couttet) (The reproductions sold in rolls are not signed)