In 1836 Collas developed a new machine that carefully copied, in mathematically precise reduction or enlargement, the relief and chiaroscuro of medallions and other bas-relief objects onto engraved steel plates, producing what he called a ‘numismatic engraving’ also known as Anaglyptograph. The collection of the Trésor de Numismatique, a precursor to photomechanical reproduction, contains over a thousand engraved plates and reproduces upward of 15,000 specimens. Brunet V, 938 (International Weekly Miscellany, No. 9, Vol.1, p. 257, August 26, 1850)