September 9, 1920] 



NATURE 



55 



Notes. 



On August 31 and September i the centenary of the 

 discoverv- of electromagnetic action by the Danish 

 physicist, Hans Christian Oersted, was celebrated at 

 Copenhagen. Meetings were held in the Town Hall 

 ,nd University, at which many Scandinavian men of 

 ience were present, and the occasion was marked 

 by the publication of some of Oersted's scientific cor- 

 respondence. It was during the winter of 1819-20 

 that Oersted observed that a wire uniting the ends of 

 a voltaic battery affected a magnet placed in its 

 vicinity, and after prosecuting his inquiries some 

 months longer, in July, 1820, he published his Latin 

 tract, " Experimenta circa effectum Conflictus Elec- 

 tric! in .Acum Magneticum." The importance of 

 his discovery received instant recognition, .\mpire, 

 .•\rago, and Davy all seized on the idea, and four 

 months after the publication of his tract Oersted was 



■ ''cted a foreign member of the Royal Society and 

 '.arded the Copley medal. Efforts to connect mag- 

 netism with electricity had hitherto met with little 

 success, and Wollaston, in his discourse as president 

 of the Royal Society, referring to Oersted's discoven,', 

 expressed the hope that " the gleam of light which 

 thus beams upon us may be the dawn of a new day, 

 in which the clouds which have hitherto veiled from 

 our sight the hidden mysteries of light and heat, 



r electricity and magnetism, may be dispelled." 



' rsted. who was the son of a country apothecary, 



iginallv studied medicine, but turning his attention 



chemistry and physics while at Copenhagen Uni- 



\ersit>', he was in 1806 appointed to the chair of 



physics, and he held that position until his death in 



March, 185 1, at the age of seventy-three. Known alike 



for his genial and kindly nature and for his scientific 



labours, he was the author of some two hundred 



"lomoirs, and received many honours at home and 



'road. Twenty-five years after his death a bronze 



ctue of him was erected on the old fortification of 



openhagen. 



The joint committee appcMnted by the Illuminating 

 'rigineering Society to inquire into the subject of 

 ve-strain in kinema theatres has now presented an 

 !!erim report to the London County Council. The 

 '>tnmittee consisted of representatives of the Illu- 

 inating Engineering Society, the Council of British 

 )|>hthaImologists, the Physiological Society, and (he 

 iiiema industry, and also received the help of various 

 iTicers of the London County Council. Its main con- 

 kisions are concerned with the undue proximity of 

 •ats to the screen as a cause of eye-fatigue. The 

 ■mmittee expresses the opinion that a high angle of 

 ■'w is one of the most important causes of eye- 

 •rain. It is accordingly recommended that the angle 

 ■n the horizontal plane passing through the 

 .it's eye and the pbne containing the observer's 



■ ve and the top edge of the picture should not exceed 

 ;,'. This is, roughly, equivalent to specifying 

 that the ratio between the distance of the nearest 

 'eats from the screen and the height of the top of 

 the picture above eye-level should not be less than 

 I : 4^ A second recommendation limiting to 25° the 



NO. 26;4. VOL. I06l 



obliquity of view from the sides of the theatre is 

 also made. The conclusions are based on actual 

 experience in a number of kinemas in London, and 

 will doubtless be accepted as moderate in scope. 

 Various other matters, such as the origin of flicker, 

 the effect of imperfect films and apparatus, and the 

 conditions of artificial lighting to be provided in halls, 

 are also dealt with, although formal conclusions are 

 not presented at this stage. With proper precautions 

 it appears that the provision of a low general illu- 

 mination in halls is consistent with a satisfactory 

 image on the screen. Such inquiries, besides being in 

 the public interest, should ultimately also be for the 

 benefit of the kinema industry, and we are glad to 

 note that several representatives of the industry 

 shared in the investigation. 



Prof. J. B. Farmer, professor of botany in the 

 Imperial College of Science and Technology, has been 

 appointed bv an Order of Council to be a member of 

 the .-Xdvisory Council to the Committee of the Privy 

 Council for Scientific and Industrial Research. 



We learn- from Science of August 20 that Dr. 

 George Ellery Hale, director of Mount Wilson 

 Observatory, has been elected a foreign member of 

 the Societi Italiana deile Scienze, Rome, in succes- 

 sion to the late Lord Rayleigh. 



Severe earthquake shocks occurred at Milan, and 

 in other parts of Northern and Central Italy, shortly 

 before eight o'clock on September 7. The centre of 

 the disturbance seems to have been in the province 

 of Massa Carrara, where several villages have been 

 much damaged and the small town of Villa Colle- 

 mandina has been destroyed. 



The next meeting of the Association of Economic 

 Biologists will be held on Friday, September 24, at 

 the Royal Botanic Gardens, Kew. At 2.30 p.m. a 

 discussion will be opened on problems of suscepti- 

 bilitv or immunity to disease in plants, the following 

 being the princip.nl speakers : — A. Howard, The Rela- 

 tion of Soil .Aeration and Soil Temperature to Disease 

 in Plants; E. S. Salmon, The Relation of Climatic 

 Factors to Disease in Plants ; and F. T. Brooks, 

 Immunity to Disease in Plants as a Mendelian Factor. 



At a meeting of delegates appointed by the scientific 

 academies of the Allied nations held in Brussels in 

 July, 1919, an International Research Council was 

 formed for the co-ordination of work and effort in the 

 various branches of science and its applications. Each 

 country, by means of its national academy or national 

 research council or its Government, can take part 

 in the scheme. We gather from an address on the 

 organisation of research delivered before the .Associa- 

 tion of .American Universities by Dr. J. R. Angell, 

 and reproduced in the July number of the Scientific 

 Monthly, that the United States has established a 

 National Research Council to deal with the organisa- 

 tion and conduct of research in that country. While 

 in Germany the work was done most effectively by an 

 autocratic Government, it was felt that in a demo- 

 cratic country an enterprise of this type could only meet 

 with conspicuous success if freed from Government 



