1522. This ship, guided by Magellan, was the first which ever sailed quite round the world; and all these voyages, proving that the earth is a round globe, and bringing back accounts of new stars in the heavens, set men thinking that there was much still to be learnt about the universe. Leonardo da Vinci, 1452.-We must not pass on into the sixteenth century without mentioning Leonardo da Vinci, the great painter, who was also very remarkable for the number of interesting inventions which he made in mechanics. Leonardo was born in 1452 at Vinci, in Tuscany; he is so generally spoken of as a painter that many people do not know that he left behind him fourteen valuable works on Natural Philosophy. He invented watermills and water-engines, as well as locks to shut off the water, such as are now used on our canals and rivers. He studied the flight of birds, and tried to make a machine for flying, and, besides being one of the best engineers of his day, he made many curious machines, such as a spinningmachine, a water-pump, and a planing-machine. Some of these things were only models which he made for his own pleasure, but they show that he, like Roger Bacon, was very much in advance of his age; and he did good service to science by the careful experiments which he made, and by insisting that it was only by going to Nature herself that men can really advance in knowledge. Chief Works consulted.-Draper's 'Hist. of Intellectual Development;' Baden Powell's 'Hist. of Natural Philosophy,' 1834; Sprengel 'Histoire de la Médecine,' 1850; 'Penny Cyclopædia,' art. 'Arabians ;' "Encyclopædias Metropolitana and Britannica;' Rodwell's 'Birth of Chemistry,' 1874; 'The Works of Geber,' Englished by R. Russell, CH. VIII. SCIENCE OF THE MIDDLE AGES. 59 1678; Whewell's History of the Inductive Sciences;' Priestley's 'History of Vision,' 1772; Smith's 'Optics,' 1778; Edinburgh Encyclopædia,' art. Chemistry; Bacon's 'Opus Majus,' by Dr. Jebb, 1733; Bacon, 'Sa Vie, ses Ouvrages, et ses Doctrines,' by M. Charles, 1861; Ventura, 'Ouvrages Physico-mathématiques de Léonardo da Vinci,' 1797; Draper's 'Conflict between Religion and Science,' 1875. |