Dictionaries, manuals, grammars, study guides and topic notes, classical authors and the entire book trade in de Viris, Quintus-Curtius, Sallust, and Livy peacefully crumbled to dust on the shelves of the old Hachette publishing house; but introductions to mathematics, textbooks on civil engineering, mechanics, physics, chemistry, astronomy, courses in commerce, finance, industrial arts- whatever concerned the market tendencies of the day - sold by the millions of copies.