NA TURE 



[December 5, 1907 



' Stratton, he perfected a remarkable machine which is' 

 ■ based on the equilibrium of a rigid body under the action 

 of springs. 



Prof. Michelson has also investigated by his interfero- 

 meter (he important subject, both theoretically and prac- 

 tically, of the breadth and the structure of spectral lines, 

 including the effect of a magnetic field, and in various 

 other ways his genius has opened up new ground in 

 experimental optics. 



Rov.\L Med.als. 



One of the Royal medals has been awarded, with the 

 approval of His Majesty, to Dr. Ernest William Hobson, 

 F.R.S. 



During the last twenty years Dr. E. W. Hobson has 

 been distinguished for the fundamental character of his 

 contributions to mathematics and mathematical physics. 

 His earlier published work, from 1888 onwards, deals 

 largely with the so-called harmonic analysis, which 

 embraces many topics having for their common aim the 

 solution of the potential equation in forms suitable for 

 application to the problems of physics. The exhaustive 

 examination of the general types of harmonic functions 

 contained in his paper in the Phil. Trans., 1896, has been 

 found to be of high utility for this application. He was 

 led by these researches, and particularly by the difficulty 

 of describing in general terms the characteristics of a func- 

 tion capable of being represented by Fourier's series, to 

 take part in the revision of the logical basis of differential 

 and integral calculus which is now in progress ; his presi- 

 dential address to the London Mathematical Society in 

 igo2 on the questions here arising aroused general interest 

 among mathematicians, and he has recently (1907) pub- 

 lished an extensive volume dealing with the whole matter 

 and its applications to the theory of Fourier's series, which 

 is of great importance for the history and development of 

 mathematics. 



His Majesty has also approved the award of a Royal 

 medal to Dr. Ramsay H. Traquair, F.R.S. Dr. Traquair 

 is honoured on the ground of his long-continued researches 

 on the fossil fishes of Palaeozoic strata, which have culmin- 

 ated, within the past ten years, in his discovery of new 

 groups of .Silurian and Devonian fishes, and in his complete 

 exposition of the structure of Drepanaspis, Phlyctenaspis, 

 and other remarkable forms. 



For nearly forty years Dr. Traquair has been busy with 

 the description of fossil fishes, mostly from the Palreozoic 

 rocks of Scotland, and he is deservedly held to be one of 

 the most eminent paljeontologists of the day. He has been 

 highly successful in the interpretation of the often very 

 obscure and fragmentary remains which he has had to 

 elucidate, and his restorations of fishes have won such 

 credit as to appear in all modern text-books of palaeonto- 

 logy. It may be said that his work, notwithstanding the 

 great difficulties of the subject, has well stood the test of 

 time. 



Dr. Traquair has done much to advance our knowledge 

 of the osteology of fishes generally. His earliest memoirs 

 on the asymmetrical skull of flat-fishes and on the skull of 

 Polypterus remain models of exactness. His acquaintance 

 with osteology enabled him to show how former superficial 

 examination of the Palfeozoic fishes had led to wrong 

 interpretations. He demonstrated that Chirolepis was not 

 an Acanthodian, as previously supposed, but a true 

 Pateoniscid. In 1877 he satisfactorily defined the 

 Palreoniscid^ and their genera for the first time, and con- 

 clusively proved them to be more nearly related to the 

 sturgeons than to any of the other modern ganoids with 

 which they had been associated. He thus made an entirely 

 new departure in the interpretation of extinct fishes, re- 

 placing an artificial classification by one based on phylo- 

 genctic relationship. His later memoir on the PlatysomidcTe 

 was equally fundamental and of the same nature. 



K\\ subsequent discoveries, many made by Traquair him- 

 self, have confirmed these conclusions, which are now 

 universally accepted. 



In 1878 Dr. Traquair demonstrated the dipneustan 

 nature of the Devonian Dipterus, and somewhat later he 

 "began the detailed study of the Devonian fishes. His 

 latest researches on the Upper Silurian fishes of Scotland 

 are equally important, and provide a mass of new know- 



NO. 1988, VOL. ']']'\ 



ledge for which we are indebted to his exceptional skill 

 and judgment in unravelling the mysteries of early 

 vertebrate life. 



Davy Medal. 



The Davy medal is awarded to Prof. Edward Williams 

 Morley. Prof. Edward W. Morley is well known bpth to 

 chemists and to physicists for his work in the application 

 of optical interferences and other physical phenomena to 

 increase the accuracy of measurement. Numerous valu- 

 able papers have appeared, either in collaboration with 

 Prof. Michelson and others, or in his own name, on such 

 subjects. Special reference may be made to his experi- 

 ments, in conjunction with Prof. Michelson, on the funda- 

 mental question of the absence of effect of translatory 

 motion of material bodies on luminous phenomena. 



His claim to the Davy medal rests on grounds closely 

 related to these researches, for he has combined thorough 

 mastery of accurate measurement with an intimate know- 

 ledge of modern chemistry, and has utilised them in his 

 attempt to solve one of the most difficult and fundamental 

 problems of chemical science. The special problem to 

 which he has consecrated many years of his life is the 

 determination of the relative atomic weights of hydrogen 

 and oxygen ; it has been attacked by him with rare insight 

 and skill, and with indomitable perseverance, and he seems 

 to have settled it for many years to come, if not perma- 

 nently. All the recent work devoted to this problem, and 

 there has been much, has tended to establish more firmly 

 the ratio arrived at by Prof. Morley. 



His determinations of the absolute weights of a litre of 

 hydrogen and of oxygen, and his investigations of the 

 amounts of moisture retained by gases dried by various 

 desiccating agents, are of the very greatest importance for 

 scientific progress. 



Sylvester Medal. 



Prof. Wilhelm Wirtinger, of Vienna, is the recipien: 

 of the Sylvester medal. He is distinguished for the import- 

 ance and wide scope of his contributions to the general 

 theory of functions. Our knowledge of the general proper- 

 ties and characteristics of functions of any number of 

 independent variables, and our ideas for the further in- 

 vestigation of such functions, are, for the most part, at 

 present bound up with the theory of multiply-periodic 

 functions, and this theory is of as great importance for 

 general solid geometry as the ideas of Abel have proved 

 to be for the theory of plane curves. Prof. Wirtinger has 

 applied himself for many years to the study of the genera! 

 problems here involved. A general summary of his re- 

 searches is given by him in the Abel centenary volume 

 (xxvi., 1902) of the "Acta Mathematica." Two of his 

 papers may be particularly referred to, both of 1895. One 

 of these deals with the reduction of the theory and general 

 multiply-periodic functions to the theory of algebraic func- 

 tions, with a view to their expression by Theta functions ; 

 this was one of the life problems of Weierstrass, who did 

 not, however, during his lifetime, publish anything more 

 than several brief indications of a method of solution. 

 Prof. Wirtinger's memoir obtains a solution, and is, more- 

 over, characterised throughout by most stimulating depth 

 and grasp of general principles. This paper was followed 

 by two others, one continuing the matter in detail, the 

 other making an application of its principles to the general 

 theory of automorphic functions. Another extensive paper, 

 which obtained the Beneke prize of the Royal Society of 

 Gottingen, deals with the general theory of Theta func- 

 tions. In it he obtained results of far-reaching import- 

 ance, for geometry as well as for the theory of functions, 

 the full development of which will require many years of 

 work. 



Hughes Medal. 



The Hughes medal is awarded to Principal Ernest 

 Howard Griffiths. Principal Griffiths has conferred great 

 benefit on physical science by his series of measurements of 

 fundamental constants, mainly in the domain of thermal 

 and electric energy. At a time when the equivalent of 

 the thermal unit in mechanical energy stood urgently in 

 need of revision, he devoted himself to the problem with 

 all the refinements and patient manipulation that could be 

 devised, the result being a value for Joule's equivalent 

 which at once acquired authority in the light of the 



