1920] on Leonardo da Vinci L23 



guished as physicist, biologist and philosopher. But in the field of 

 science he was essentially a forerunner. The results that he achieved 

 must be reckoned as small compared with his grasp of basic principles, 

 with the vistas that he opened up, and the unerring instinct Avhich 

 he displayed in choosing the true method of investigation. 



Science, as he held, came by observation, not by authority, but 

 to say this is not to deny the use of the inherited wisdom of the 

 ancient writers as being the natural starting point of all knowledge, 

 even that founded on observation and experiment. References to 

 the scientific authors of antiquity occur frequently in the manuscripts, 

 and a few memoranda as to the whereabouts of books which he 

 apparently intended to consult may be quoted as showing how this 

 knowledge was built up as occasion offered. 



"Enquire at the Stationer's about Yitruvius," and, again, " Messer 

 Ottaviano Palavicino for his Yitruvius." 



" The Archimedes which belongs to the Bishop of Padua." 



" Maestro Stefano Caponi, a physician, lives at the piscina and 

 .has Euclid ' De Ponderibus.' " 



" The heirs of Maestro Giovanni Ghiringallo have the works of 

 Pelacauo." 



" An algebra, which the Morliani have, written by their father." 



" Try to get Yitolone which is in the Library at Pavia, and 

 which treats of mathematics." 



" A grandson of Gian Angelo the painter has a book on water 

 which belonged to his father." 



A list of forty books of a more general character on a page of 

 the Codice Atlantico is generally accepted as indicating a portion of 

 Leonardo's own library ; among the titles are an Arithmetic, a Bible, 

 a copy of the Psalms, Pliny, Livy, Ovid's Epistles, Petrarch, and 

 the Travels of John de Mandeville. 



References also occur in the manuscripts to Latin poets, Virgil, 

 Horace, Lucretius, but far more numerous are the references to his 

 predecessors in scientific investigation, such as Aristotle and Archi- 

 medes. He refers also to Avicenna, Galen, Clemedes, Hippocrates, 

 and Roger Bacon. 



The predominantly scientific character of his mind is shown by 

 the fact that the record of his friendships is concerned almost 

 exclusively with his scientific pursuits. In a note in the manuscripts 

 he says, " Vespuccio will give me a book of Geometry," and Yasari 

 says that he made a drawing of the head of Amerigo Vespucci as an 

 old man, this being presumably after his return to Florence in 1502, 

 as Vespucci was born in 1451. The friendship thus indicated must 

 have stimulated that interest in physical geography which led to his 

 making enquiry by letter of the condition of the tides in the Black 

 and Caspian Seas, and may have been instrumental in causing him 

 to construct many maps. A map of the world attributed to him, in 

 the Royal Library at Windsor, is the earliest map on which the name 



