The KBCB has received a major donation of almost 500 books for its library. They belonged to Stefan Banz (1961-2021) and are devoted exclusively to the artist Marcel Duchamp (1887-1968). For several years, Banz and his partner Caroline Bachmann devoted themselves to an impressive project based on Duchamp's last work, Étant donnés: 1° la chute d'eau, 2° le gaz d'éclairage... (1946-1968). It all started with a discovery: the waterfall reproduced in miniature in Duchamp's work was modelled on the Forestay waterfall in the Lavaux region, just a few kilometres from Cully, where the couple lived. This discovery led the couple to carry out unprecedented research into the work. In 2010, this led to the organisation of an international symposium in Cully, which will be followed by a major publication. This work on the Forestay waterfall prompted Banz to take an interest in another aspect of Duchamp's work. Étant donnés is in fact a kind of diorama to which we have access only through two small holes drilled in an old wooden door. Banz has meticulously studied what this mise en scène owes to the New York painter Louis Michel Eilshemius (1864-1941), for whom Duchamp had great admiration.