3624840 Straightening of the walls at the Conservatoire des Arts et Metiers (engraving) by European School, (19th century); Private Collection; (add.info.: Straightening of the walls at the Conservatoire des Arts et Metiers. Illustration for The Phenomena and Laws of Heat by Achille Cazin translated by Elihu Rich (Scribner, Armstrong, 1872). Digitally cleaned image.); by Look and Learn.