122 Mr. Edward McCurdy [March 19, 



is well made, that is to say made of linen of which the pores are 

 stopped up with starch, and is turned swiftly, the said screw will 

 make its spiral in the air, and it will rise high." 



He adds that a small model may be made of cardboard with the 

 axis formed of fine steel wire bent by force, and that this when 

 released will turn the screw. To his drawing of this instrument the 

 architect Luca Beltrami has— to me, as it seems, justly— applied the 

 word aeroplane. 



Another page in the Codice Atlantico (311 v. d.) of unique 

 interest contains three studies of artificial wings, a name, and a note 

 that the machine is to be made not with " sportelli" that is shutters, 

 but united. The natural interpretation is that the note refers to a 

 commission for the construction of a machine for flight, with regard 

 to which the patron Gian Antonio de Mariolo has expressed a desire 

 that the wings should be such that no wind would be able to pass 

 through them as it would if they had shutters, i.e. should be like the 

 wings of the bat. 



I might occupy as many hours as I have minutes at my disposal 

 without in any way exhausting the sum of his researches in natural 

 and applied science. They cover so wide a field, and specialisation 

 in these days has so divided knowledge into water-tight compart- 

 ments, that to properly gauge the value of his contributions to 

 scientific research would require a combination of many trained 

 intelligences. But it is not possible to devote a number of years to 

 the close study of all that concerns Leonardo without becoming 

 imbued with the conviction of the complete oneness of his work and 

 method. The dominant purpose which animates him, whatever the 

 nature of the problem, is to investigate, to examine, and define 

 primary causes. His pen reinforces his practice. "Nature," he 

 says, " is constrained by the order of her own law, which lives and 

 works within her." Again, " There is no result in nature without a 

 cause ; understand the cause and you will have no need of the 

 experiment " ; and, " Nature is full of infinite causes which were 

 never set forth in experience." 



Maybe the purpose to investigate arose primarily out of what he 

 conceived to be the necessities of his art. " The painter," as he 

 says, " contends with and rivals nature," and as a means to this end 

 he must acquire all possible knowledge of her processes. 



With Leonardo the latter end of this search forgot the beginning. 

 His intellectual curiosity into the origins and causes of all created 

 things is revealed in infinite variety in the thousands of pages of his 

 manuscripts, compact, as has been said, " of observation, of pro- 

 phecy, of achievement," and in this triple legacy forming a record 

 probably unequalled, certainly unsurpassed, by that of any other man 

 in the history of the world. For consider what he was ! Printer, 

 painter, sculptor, engineer, architect — all these to the wonder of his 

 contemporaries. His manuscripts reveal that he was no less distin- 



