MEP2380679: Mario Crepaz at work on board Leonardo da Vinci / Bridgeman Images

MEP2380683: Mario Crepaz in the cockpit of the transatlantic Leonardo da Vinci / Bridgeman Images

LSE4095884: The Virgin - School of Leonardo da vinci, Museum of Menton, Vinci, Leonardo da (1452-1519) (school of) / Bridgeman Images

DGA548581: Grotesque heads, 1730, by Anne-Claude-Philippe (aka Count de Caylus, 1692-1765), from works by Leonardo Da Vinci, engraving. / Bridgeman Images

DGA3938223: Perspectives, layouts and architectural details of a mobile house used as temporary residence or office, designed by Oppermann, engraving from Nouvelles annales de la construction, 1877 / Bridgeman Images

DGA3938529: Cosmographical plate, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938574: Screw bombard, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938585: Counterweight trebuchet, siege engine, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3939637: Woodcut from De re militari libri quatuor (Epitoma rei militaris), by Publius Flavius Vegetius Renatus, printed by Christian Wechel, Paris, 1535 / Bridgeman Images

DGA3939638: Woodcut from De re militari libri quatuor (Epitoma rei militaris), by Publius Flavius Vegetius Renatus, printed by Christian Wechel, Paris, 1535 / Bridgeman Images

DGA3939370: Bronze shield with figures of warriors in relief / Bridgeman Images

SSI2207655: Roller Bearing (b/w photo), Unknown photographer, (20th century) / Bridgeman Images

DGA3938535: Crossbows, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938571: Crossbowman, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938582: Counterweight trebuchet, siege engine, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938593: Battle flag, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938573: Bombard mounted on a wooden frame, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938576: Bombards mounted on gun carriages, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938583: Counterweight trebuchet, siege engine, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938594: Battle flag, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

TEP445774: Caricatures and deformities after Leonardo, 1645 (etching), Hollar, Wenceslaus (1607-77) / Bridgeman Images

DGA3938612: Life-belts, woodcut from De re militari, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938551: Water-drawing device, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938584: Counterweight trebuchet, siege engine, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3939375: Silver censer / Bridgeman Images

DGA3939385: Red-figure terracotta vase with lid / Bridgeman Images

DGA3939388: Red-figure terracotta vase / Bridgeman Images

DGA3939632: Woodcut from De re militari libri quatuor (Epitoma rei militaris), by Publius Flavius Vegetius Renatus, printed by Christian Wechel, Paris, 1535 / Bridgeman Images

MEV5049169: Leonardi Hall, Bibliioteca Ambroisana, Milan (colour photo) / Bridgeman Images

DGA2583196: Barometer, 19th century / Bridgeman Images

DGA3939405: Cloisonne metal box / Bridgeman Images

DGA3938232: Scales, engraving from Nouvelles annales de la construction, 1882 / Bridgeman Images

DGA3938544: Armored siege engine, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3938599: Battle flag, woodcut from De re military, by Roberto Valturio, printed by Christian Wechel, Paris, 1532 / Bridgeman Images

DGA3939618: Mantelet, woodcut from De re militari libri quatuor (Epitoma rei militaris), by Publius Flavius Vegetius Renatus, printed by Christian Wechel, Paris, 1535 / Bridgeman Images

DGA3939631: Siege ladders, woodcut from De re militari libri quatuor (Epitoma rei militaris), by Publius Flavius Vegetius Renatus, printed by Christian Wechel, Paris, 1535 / Bridgeman Images