756 



SCIENCE. 



.[N. S. Vol. VII. No. 178. 



talented inventor, a skilled mechanic, and per- 

 haps the most learned scientific man of his age 

 and nation. 



The fact is that it was Leonardo who re-im- 

 ported, more than any other scientific man of 

 his time, the sciences of the Saracens, after 

 their migration from ancient Greece with the 

 disciples of Aristotle and the Ptolemies, and 

 their long residence in Egypt, their incorpora- 

 tion with the older learning of the Orient and of 

 the Arabs, and their purification and systema- 

 tization by union with the mathematical, and 

 especially the astronomical, sciences of those 

 builders of its most solid foundations. It was 

 Leonardo who made applied science systematic, 

 who studied botany as a biologist, interpreted 

 geolog5% laid the scientific foundation of pro- 

 fessional engineering construction, and who, in 

 his studies of the true theories of mechanics, 

 and of their utilization in the arts of war and 

 of peace, made of himself that type of the 

 modern man of science now most characteristic 

 of our own time, the man of science employing 

 a combination of pure and applied science in 

 the iJromotion of all the arts of the civilization 

 of his time. These facts are not always even 

 suspected by the reader of existing biographies, 

 but a study of this unique collection of helio- 

 typed plates, fac similes of his drawings, will 

 bring the true character and the real life and 

 habits of the man into view, and will throw into 

 high relief the most important characteristics 

 of his genius. 



This graphical autobiography is the story of 

 the life and work and inmost thought of the 

 man, without intermediary. It shows him 

 constantly engaged in devising new machinery, 

 usually of war, with new plans for the applica- 

 tion of scientific learning, of reduction to prac- 

 tice in the art of war, principally, of the then 

 novel discoveries of science ; utilizing the re- 

 tui-ning current of physical, chemical and me- 

 chanical sciences ; then recrossing the Mediter- 

 ranean, never to be again lost to Europe or the 

 world. 



These singularly interesting drawings are re- 

 produced with all the fidelity coming of the 

 use of heliographic processes ; and one of the 

 interesting and curious evidences of the fact 

 that they are made perfect fac similes, without 



reference to their character, is seen in the in- 

 scriptions, autographic incriptions by Leonardo^ 

 which must be read by the use of a mirror. 

 The Italian is perfectly good and intelligible ;; 

 but, until it is noted that the plates are thu& 

 reversed, it is somewhat of a puzzle to the stu- 

 dent of Leonardo's sketches. The whole con- 

 stitutes, that form of condensation of the in- 

 vention and the arts for his time, which is simi- 

 larly illustrated by Hero, the Greek author, 

 many centuries earlier, in his ' Pneumatica, ' 

 and by Branca, by Leupold and by others since, 

 in other places and in more modern times. The 

 work will have value from many points of view 

 and will find its place in every library of im- 

 portance. It should, and undoubtedly will, be- 

 come familiar soon to all collectors, to all 

 men of science, and to the professional poster- 

 ity of Leonardo among members of the engi- 

 neering professions. Its publication cannot 

 fail to add enormously to the fame of an already 

 famous man who has rightfully been regarded, 

 even in the absence of this testimony, as per- 

 haps the most eminent example of the ' uni- 

 versal genius,' in science, literature and art, 

 and the arts as well, yet given a place in his- 

 tory. 



Leonardo, the biologist, anatomist, botanist, 

 hydraulician, geometrician, algebraist, mech- 

 anician, optician, the inventor of the marble- 

 sawing machine, a rope-making apparatus, of 

 innumerable varieties of ballistic machines and 

 ordnance, the seer of coming steam-engines and 

 of steam-navigation and transportation, of 

 steam-guns and breech-loading arms with the 

 ' modern ' screw-breech-block, of canals and 

 other engineering works, the maker of un- 

 counted plans, designs and inventions ; in 

 fact, this Leonardo is revealed, not in biogra- 

 phies, but in his manuscript, of which even this 

 great Codex constitutes only a fraction. Such 

 widely distributed interests and such variety 

 of talent could not be exhibited to-day, even 

 by a man like Leonardo, of rare genius, un- 

 equaled talent, indefatiguable industry and un- 

 limited ambition ; and even in the sixteenth 

 century this universality of genius was without 

 rival among men of science, and Leonardo's 

 was the noblest mind of his time. 



R. H. Thtteston. 



