January 21, 19 15] 



NATURE 



D/O 



universal reply, which is a certain proof of victor}- 

 for our ideal. 



Amongst the scientific events of the year, prominent 

 mention is due to the unveiling of the monument of 

 our colleague Marey, one of those men to whom 

 modern physiology owes so much. As M. Richet has 

 said (■■ Inauguration du monument eleve a la memoire 

 de Etienne Jules Marey, au Pare des Princes, a 

 Boulogne-sur-Seine, le mercredi 3 Juin, 1914"; Paris : 

 Gauthier-Villars), he is one of those who leave a work 

 so firm, so fruitful, so perfect that every year adds to 

 its renown. In fact, time takes no toll on a well- 

 founded scientific work. The pages of Descartes on 

 "la Geometrie analytique," of Harvey on "the con- 

 tractions of the heart," of Lavoisier on "les combus- 

 tions respiratoires," remain intact and intangible, like 

 the Greek marble statues, the beaut\- of which remains 

 unchanged after a lapse of twenty centuries. The 

 idea conceived by Marey in his youth and realised b)' 

 him in his work was the creation of methods per- 

 mitting the direct and precise inscription of motion, 

 either by graphical records, or by photographs taken 

 at intervals so short as to appear continuous. A 

 running man, a galloping horse, a flying bird, a 

 beating heart, execute movements only a confused 

 average of which can be seized by the eye. The 

 photographs of Marey give an exact analysis of them ; 

 it is only necessary to realise the synthesis of the 

 successive images by the aid of a method employed a 

 long time ago in certain toys to obtain a kinemato- 

 graph. This apparatus, possessing innumerable scien- 

 tific applications, has then its origin in the worx of 

 Marey. 



It presents the great philosophic interest of giving 

 control of the time, which, until then, had been the 

 one independent variable. Once a phenomenon is 

 recorded it can be repeated in its successive phases, 

 accelerating or retarcfing at will. Thus deceleration 

 permits the study at leisure of the beats of the heart, 

 the movements of a bird's wings, and acceleration 

 shows in a few minutes the germination of a plant or 

 the hatching of an egg. It is even possible to change 

 the sign of the variable and reverse the order of 

 events. Marey then was an inventor of genius, a man 

 who extracted something from nothing; the improve- 

 ment of a discoven" is a small matter, the essential 

 point is to make it. 



This year French physicists have been actively occu- 

 pied with the construction of a huge electromagnet, 

 in which the intensity- and dimensions of the field were 

 to be much greater than those of the most powerful 

 apparatus in current use. A magnet of this nature 

 would permit of absolutely new researches on the 

 magnetic properties of matter at different tempera- 

 tures, on the constitution of crystals, on Zeeman's 

 phenomenon, rotatory magnetic polarisation, and, in 

 another order of work, on modifications of vital 

 phenomena under the action of the magnetic field. 

 The council of the Faculty- of Science of Paris, struck 

 with the importance of these researches, had reserved 

 from the funds placed at its disposition by the 

 liberality of M. Commercy for the advancement of 

 science a sum of 50,000 francs, as a first contribution, 

 although small, to the total expenditure required for 

 the realisation of the scheme. Prince Bonaparte, who 

 is alwaj's ready with active generosity to support 

 great French scientific enterprises, has taken an active 

 interest in this question. At his request an official 

 committee, composed of the most competent members 

 of our academy, was constituted, in order to study 

 under what conditions France could be endowed with 

 an instrument that should be unique in the world. 

 This committee has held numerous meetings to dis- 

 cuss the various suggestions and hear the best-known 



NO. 2360, VOL. 94] 



specialists; its results have been published in a 

 pamphlet which is a credit to our academy. Without 

 quoting any names, the conclusions may be sum- 

 marised thus : it is desirable that an important labora- 

 tory of magnetic research should be created; this 

 laborator)- should be placed under the patronage of 

 ; the academy, and administered by the Universit)' of 

 ' Paris; in this laboratory should be installed the most 

 • powerful electromagnets of the tj'pes chosen. 



While we are thus dreaming of a gigantic magnet 

 destined to enlarge the field of human knowledge, 

 Germany, carried away by its dream of world-domina- 

 tion, prepared in secret enormous mortars in view of 

 a sudden overwhelming attack on Belgian and French 

 fortresses; when the time was thought favourable, 

 war was declared against Russia and France, and 

 Belgian neutrality was violated. Since the first days 

 in August our academy has had but one thought, to 

 assist the Government in the defence of the country 

 and libert}'. 



At the meeting of August 3, the academy notified 

 the Government that all its members who were not 

 mobilised in the public service held themselves in 

 readiness to aid in the national defence, each accord- 

 ing to his speciality. After the meeting six large 

 committees \vere constituted under the following 

 denominations : — (i) Mechanics (including Aviation) ; 

 (2) Wireless Telegraphy ; (3) Radiography ; (4) Chem- 

 istry (including Explosives) ; (5) Medicine, Surgerj-, 

 Hygiene ; (6) Food. All these committees have worked 

 their hardest; the time has not come to speak of the 

 reports which they have presented and the results 

 they have obtained. 



On August 10 the academy addressed to its corre- 

 spondants in Belgium, M. Boulvin at Ghent, and M. 

 Francotte at Brussels, the expression of its brotherly 

 friendship and its profound admiration for the Belgian 

 people and army. W'e solemnly renew to-day the 

 expression of these sentiments, adding our indignant 

 protest against the destruction of the treasures of art 

 and science; the acts of violence on the libertv", life, 

 and property of the non-combatants, committed 

 deliberately in order to punish noble nations because 

 they did not hesitate in their choice between the laws 

 of honour, the respect for treaties, the love of in- 

 dependence, and the base suggestions of material 

 interest or of fear. 



yi AT HEMATICS IX ARTILLERY SCIENCE. 



SIR GEORGE GREEN HILL, president of the 

 Mathematical Association, delivered an address 

 upon " Mathematics in Artillery Science " at the 

 annual meeting of the association on January" 9. We 

 have been unable to obtain a copy of the address from 

 the officials of the association, though we think that 

 one of the chief purposes of a scientific society should 

 be to secure as wide a publicity- as possible for its 

 papers and addresses. Sir George Greenhill's re- 

 marks have, however, been summarised in the daily 

 papers, and from the Times report the subjoined 

 abstract has been derived. We may add that as Sir 

 George was formerh- professor of mathematics in the 

 Artillery College, Woolwich, his opinions upon the 

 position which science occupies in our technical train- 

 ing for modern warfare must be given careful con- 

 sideration. 



Six months ago artillery officers would have said 

 there was no such thing as mathematics in artillery- 

 science; but that outlook was now ancient histor}% 

 for at the present time we are engaged in what is, 

 in fact, a mathematical war. Drawing upon his 

 experience as a professor of artiller\- theory for in- 



