May 6, 1920] 



NATURE 



309 



Mich as found expression, either mainly or in part, in 

 Lonstructive work and jLhose revealed only in his 

 writings. The first category comprises painting, 



ulpture, architecture, and engineering. In painting 



is enough to instance the fresco of the Last Supper 

 tiiid the portrait of Mona Lisa, each of its type 

 unique among all works of the Renaissance, and 

 beyond all power to appraise in its union of technical 

 mastery and the inevitability of supreme art. In 

 sculpture the Sforza statue, the master-work of his 

 Milanese years, lives only in the drawings which 

 furnish some faint index of its power. In architec- 

 ture there is no outstanding memorial. 



Sir Theodore Cook, in his elaborate study of spiral 



ims entitled "The Curves of Life," has collected a 



inarkable array of evidence in favour of attributing 

 10 Leonardo the design for the oj^en spiral staircase in 

 the Chateau of Blois. The documentary evidence is 

 missing, but the date of construction is known to 

 have been between the years 1516 and 1519, and 

 Leonardo was then living a few miles distant in the 

 iKinor-house of Cloux, near Amboise. A spiral stair- 



se occurs in one of Leonardo's drawings for a 



rtified tower, and he made many studies of spiral 



lormations occurring in Nature, in shells, in smoke, 



nul in the eddies of water. The staircase at Blois is 



Mparently modelled on Voluia vespertilio, a shell 



mmon on the coast of northern Italy. The theory 



IS obvious attractions. It supplies an example of a 

 Aork in architecture emanating from the brain of 

 Leonardo, and this a work of supreme distinction. 



Records of his activity as an engineer are con- 



ined with schemes of canalisation in Florence, 

 connection with the diversion of the Arno 

 iiom Pisa as a war measure; and in Friuli, in 

 similar circumstances, he devised movable sluices 

 in order to prevent the advance of the Turks across 

 the Isonzo. He made canals in Lombardy for pur- 

 poses of irrigation, and also aqueducts to improve the 

 water-supply of Milan ; and the canal of Romorantin, 

 for which he made plans when in France, was 

 intended to connect the waters of the Loire and the 

 Sa6ne. 



The potential list of Leonardo's activities in the con- 

 struction of instruments of warfare figures in the letter 

 to Ludovic Sforza. He says there : " I can make 

 armoured wagons safe and immune from attack which 

 will open up a passage through the enemy with their 

 artillery, and, however great the multitude of the 

 enemy mav be, thev will be able to break through. 

 And behind them the infantry will be able to follow 

 quite unhurt and without hindrance." 



This armoured wagon is seen ready for action in 

 .1 drawing in the British Museum. It is moved on 

 wheels, and a sketch of the lower half shows the 

 internal machinery, but it is not possible to discern 

 I lie nature of the motive power. The use of the 

 .-irmoured wagon in order to open up a passage 

 through the enemy, as described above, is identical 

 with that of the tank in the late war. The manu- 

 ^. ripts reveal a strangely prophetic insight in regard 



two other developments of recent warfare, namely, 



ison gas and submarining. 



Leonardo contemplated the use of poisonous gas 

 powders in naval warfare for the purpose of 



ifnrating the enemv, and told how to make a simple 

 preventive mask. He also contemplated the con- 

 tingency — as happened on occasions in Flanders — of 

 -n adverse wind causing the poison to recoil upon 

 usprs. The passage, which occurs in MS. B 



the Paris manuscripts, is entitled "How to throw 

 poison in the form of powder upon ships." 



"Bv means of catapults," he says, "a mixture of 

 powdered quicklime, arsenic, and verdigris may be 

 NO. 2636, VOL. 105] 



thrown upon the ships of the enemy, and all who 

 inhale the powder will die. 



" But take care that the wind is favourable, lest it 



j blow the powder back upon you, and be sure you 



j have a fine piece of damp cloth to cover the nose and 



I mouth in order that the powder may not enter." 



I In the Leicester manuscript (folio 22b) he foretells 



! the horrors of submarine warfare, and refuses to 



impart any information as to the machine which he 



has constructed lest it should serve to bring them 



about : 



" How by means of a certain machine many people 



may stay some time under water. How and why I 



; do not describe my method of remaining under water, 



or how long I can remain without eating; and I do 



not publish or divulge this because of the evil nature 



of men who would use them as means of destruction 



at the bottom of the sea by smashing the ships in the 



i keel and sinking them together with the men in them. 



! But I will impart others which are not dangerous, 



because the mouth of the tube by which you breathe 



appears above the water supported on leather bottles 



or corks." 



In connection with this passage reference may be 

 made to one in MS. B of the Paris manuscripts 

 entitled "A Way of Escaping in a Tempest or Ship- 

 wreck at Sea," in which Leonardo tells how to con- 

 struct a coat of leather of double thickness which will 

 be capable of being inflated when necessary, and thus 

 of serving as a life-saving jacket in case of emergency. 

 Senatore Luca Beltrami associates the former of 

 these passages with the Turkish war. Leonardo, as 

 a reference to his manuscript shows, had been em- 

 ployed in the construction of a movable dam which 

 should enable the line of the Isonzo to be flooded in 

 i the defence of the Veneto against the Turkish in- 

 : vasion. The reference is to the construction of sub- 

 \ marine boats in order to sink the Turkish galleys in 

 ' the Gulf of Venice " by smashing the ships in the 

 I keel and sinking them together with the men in 

 them." Leonardo considers this to be justifiable, 

 because it is an act of defence " for the safety of our 

 Italian lands" (" delli nostre parti italiche"); but he 

 will not give any details of the construction of his 

 submarine craft in which it would be possible to 

 remain under water for four hours, because he is 

 fearful of the evil use to which it might be put in 

 future times. 



(To be continued.) 



Public Support of Scientific Research. 



ON Wednesday, April 28, a public meeting was 

 held at Birkbeck College to hear an address 

 from Prof. F. Soddv on "The Public Support of 

 Scientific Research."' Mr. H. G. Wells, who took 

 the chair, claimed that everything in which the world 

 of to-day differed from that' of years ago was due to 

 science and the scientific worker. Prof. Soddy ex- 

 pressed his regret that the greater encouragement 

 of scientific research during the war had not resulted 

 in any appreciable improvement in the position of 

 pure science, which was the tree of which applied — 

 industrial and trade— science were the fruits. He 

 deprecated the exploitation of science by financiers 

 and commercial men and its employment to increase 

 the indebtedness to them of those who had done the 

 creative work of the world. The scheme framed by 

 the Government to foster scientific research en- 

 deavoured to place the man of science who was to 

 do the work under the same type of men — often the 

 same men— as had thwarted progress in the past. 

 The change from gross inefficiency in the medical 



