December 7, 191 1] 



NATURE 



183 



of the same work in the twentieth century as the •" Inter- 

 national Catalogue of Scientific Literature." 



Having gone to so much trouble and expense in the 

 preparation of the materials for these subject-indexes, the 

 society is natuially desirous to see that the results become 

 accessible to the scientific public, for whose use the 

 volumes are intended. All the funds which the Royal 

 Society can possibly devote to this work are necessary 

 for its completion ; thus there can be no question of free 

 exchange, as was the case with the earlier volumes, how- 

 ever much the Royal Society might desii-e it. But, as the 

 fellows are already aware, the Cambridge University Press 

 has consented to undertake the entire risk of printing and 

 publication, and has agreed to sell the volumes at a very 

 moderate price. We are informed that the volumes of the 

 index already issued have, for some reason, not yet 

 attracted the attention among universities and public 

 libraries that was confidently anticipated. 1 have therefore 

 thought it desirable to bring this matter to notice to-day. 



On July 15 of next year the Royal Society will have 

 lived for exactly two centuries and a half. Looking back 

 upon this long career, and considering the friendly rela- 

 tions which the society has for generations maintained with 

 the men of science in all quarters of the globe, the presi- 

 dent and council have thought that the occasion will be 

 one which ought not to be passed over in silence, but which 

 deserves to be marked in some worthy way. They have 

 accordingly decided to invite the chief universities, 

 academies, scientific societies, and other institutions in this 

 country, in our colonial dominions, and abroad, to send 

 delegates hither to join with us in celebrating our 250th 

 birthday. The invitations will be issued next month, so 

 as to allow ample time for the selection and the arrange- 

 ments of the delegates and for our own preparations here. 

 Our patron, his Majesty the King, has been pleased to 

 signify his appreciation of the importance of our proposed 

 celebration. Though the details of the function have not 

 yet been settled, it is thought that the first reception and 

 welcoming of our guests should be held in our own rooms, 

 which, with their portraits and other memorials of our 

 past, will doubtless be of interest to the visitors. For the 

 banquet, at which the fellows and their guests will dine 

 together, we hope to enjoy the use of a large hall specially 

 lent to us for the occasion. Considering the early associa- 

 tion of the Royal Society with Gresham College and the 

 Cit\', we trust that some opportunity will be afforded to us 

 of renewing that intercourse, and thus of allowing our 

 delegates to partake of the well-known hospitality of 

 London. There will doubtless be a good deal of private 

 hospitality. Of course, every facility will be arranged for 

 our guests to see public buildings, museums, libraries, and 

 other objects of interest. At the end of the function in 

 London, the delegates may not improbably be invited to 

 visit the Universities of Oxford and Cambridge. 



As a permanent memento of the occasion, the council 

 has decided to reproduce in facsimile the pages of the 

 charter-book, containing the signatures of the fellows from 

 that of the founder, Charles II., down to the present day. 

 I^This interesting volume is now in course of preparation at 

 le Oxford University Press. It has also been arranged to 

 Kssue a new edition of the society's " Record," in great 

 part rewritten, closely revised, and brought up to date. 

 H This volume is also in progress. 



MEDALLISTS, 1911. 

 The Copley Medal. 

 The Copley medal is this year awarded to Sir George 

 Howard Darwin, for his long series of researches on tidal 

 theory, including its bearing on the physical constitution of 

 the earth and on problems of evolution in the planetary 

 system. 



As regards the actual oceanic tides, he has perfected the 

 method of harmonic analysis initiated by Lord Kelvin, and 

 has greatly promoted its practical application by the inven- 

 , tion of simplified methods of ascertaining the tidal constants 

 3f a port from the observations and of framing tide-tables. 

 'In another series of researches the tides of a solid planet 

 of slightly viscous material are investigated, including the 

 consequent secular changes in the motion of the planet and 

 of the tide-generating satellite. He traced from this point 

 of view the past history of the earth and moon, and was 



NO. 2197, VOL. 88] 



led to the now celebrated hypothesis that the latter body 

 originated by fission from its primary when in a molten 

 state. 



He has further studied in great detail the classical 

 problem as to the possible figures of equilibrium of a 

 rotating mass of liquid and their respective stabilities, 

 which has engaged in succession the attention of Mac- 

 laurin, Jacobi, Kelvin, and Poincar^. The difficult theory 

 of a binary system composed of two liquid masses revolving 

 in relative equilibrium, now known as Roche's problem, 

 has been greatly developed and extended by him. Such 

 investigations have, of course, an important bearing on the 

 theory of the evolution of the earth-moon system already 

 referred to. 



The above is a mere summary of the main lines of Sir 

 George Darwin's activity. There are, in addition, a 

 number of highly important memoirs on more or less 

 cognate subjects. For example, in dealing with the ques- 

 tion as to the degree of rigidity of the earth as it now 

 exists, he has treated it from various points of view ; he 

 has considered the theory of the long-period tides, and the 

 stresses produced in the interior by the weight of continents 

 and mountain chains. Mention should also be made of 

 remarkable papers on the history of meteoric swarms, and 

 (in the domain of the more classical astronomy) on periodic 

 orbits. 



Royal Medals. 



The assent of his Majesty the King has been signified 

 to the following awards of the two Royal medals : — 



The Royal medal on the physical side was assigned to 

 Prof. George Chrystal, of Edinburgh University, on 

 account of his contributions to mathematical and physical 

 science, especially, of late years, to the study of seiches on 

 lakes. Conspicuous in his early years as one of Clerk 

 Maxwell's principal lieutenants, it is to him that we owe 

 the experimental proof of the extreme precision of Ohm's 

 law of electric conduction (Brit. Assoc. Report, 1876). His 

 memoir on the differential telephone (Trans. Roy. Soc. 

 Edin., 1880) was a notable early extension of the theory 

 and practice of Maxwell's principles as regards inductances,, 

 now become more familiar when power transmission, as. 

 well as telephonic intercourse, proceeds by use of alter- 

 nating currents. His duties as a teacher of mathematics 

 led to the "Treatise on Algebra," which, besides being a 

 book of original vein, was the earliest systematic exposi- 

 tion in our language of the more rigorous methods 

 demanded in recent times in algebraic analysis. But this 

 purely mental discipline, and its continuation in various 

 memoirs on abstract mathematics, could not wholly occupy 

 a mind trained originally in the school of physical science. 

 Of late years Prof. Chrystal had been engaged with great 

 success in a most interesting subject of research, in the 

 theory and the observation of the free persisting oscilla- 

 tions of level in lakes, first observed and analysed by Fore! 

 on the Lake of Geneva. 



At the moment when the council was adjudicating this 

 medal it was unaware that the illustrious mathematician 

 at Edinburgh was then lying on his death-bed. He had 

 been in failing health for some time, but the latest news 

 was more favourable. The end came, however, before he 

 could learn that a Royal medal had been assigned to him. 

 In these circumstances it was felt that the award should 

 not be cancelled, but that the medal should be transmitted 

 to his family as a visible token of the admiration with 

 which the Royal Society regards his life-work. On appeal- 

 ing for the sanction of the Royal donor of the medal, his 

 Majesty was pleased to approve of our proposal, and to 

 add aii expression of his condolence : " The King trusts 

 that vou will be so good as to convey to the family the 

 assurance of his Majesty's sincere sympathy in the terrible 

 loss that they have sustained, through which ^ so dis- 

 tinguished a career has been brought to a close." Those 

 who had personal acquaintance with Prof. Chrystal mourn 

 the extinction of ? life full of charm and brightness. 



The Royal medal on the biological side has been 

 awarded to William Maddock Bayliss, F.R.S. During the 

 last twenty-five years the part taken by Dr. Bayliss in the 

 advancement of physiology has perhaps been unequalled by 

 any other physiologist in this country. His work has 

 ranged over a wide field. In his earlier papers dealing 

 with the electrical phenomena associated with the excita- 



