
Original poster by Andry-Farcy for this exhibition, intended to promote both the hydroelectric industry and tourism in a city whose industrial expansion was then closely bound up with hydroelectric power: the expression "houille blanche" (literally "white coal") referred to the hydraulic energy of waterfalls and watercourses, converted into electrical power.
Sheet slightly yellowed, with traces of folding and a few tears, some of them along the folds.