92 Anniversary Address by Lord Rayleigh. [Nov. 30, 



Callendar devised a continuous electrical method of attacking this problem, 

 possessing many important advantages as compared with older methods. He 

 was assisted by Dr. Barnes in carrying out this work, the results of which 

 form the subject of papers by Callendar and Barnes in the ' Phil. Trans. Eoy. 

 Soc.,' 1901. As an illustration of the probable accuracy of their results it 

 may be observed that, whereas by any of the older formulae accepted for the 

 variation of the specific heat of water the values of Kowland and of Eeynolds 

 and Moorby for the mechanical equivalent are seriously discordant, they are 

 brought into perfect agreement by the work of Callendar and Barnes. 



In the subject of conduction of heat Professor Callendar has contributed 

 many original methods described in various minor papers, and, in addition to 

 the thermal investigations with which his name is chiefly associated, has 

 carried out some purely electrical researches. 



One of the Koyal Medals has been awarded, with the approval of His 

 Majesty, to Professor Alfred George Greenhill, a Fellow of the Society, 

 on account of the number and importance of his mathematical investi- 

 gations produced between the year 1876 and the present time. They 

 embrace a variety of mechanical and physical subjects, including dynamics, 

 hydromechanics, electricity, and gunnery. He is the author of two treatises 

 on hydromechanics, both remarkable for originality of treatment. 



The subject, however, to which he has devoted most time and attention is 

 the theory of elliptic functions. His work on this subject may be placed 

 in two classes : (1) Investigations in which he has extended the subject into 

 new fields, as in the series of memoirs on the " Transformation and Complex 

 Multiplication of Elliptic Functions," contributed to the ' Proceedings of 

 the London Mathematical Society ' (vols. 19, 21, 25, 27), and in the memoir 

 on the " Third Elliptic Integral and the Ellipsotomic Problem," in the 

 ' Phil. Trans. ' (vol. 203). (2) Applications to Mechanical Problems, mainly 

 dynamical, for purposes of calculation or illustration. In this class may be 

 placed his treatise on the Elliptic Functions, as well as numerous papers in 

 journals and the proceedings of scientific societies. 



All Professor Greenhill's work is characterised by much originality, and 

 by a rare power and skill in algebraic analysis. 



His Majesty has also approved the award of a Pioyal Medal to 

 Dr. Dukinfield Henry Scott, also a Fellow of the Society, for his investi- 

 gations and discoveries in connection with the structure and relationship 

 of fossil plants. Dr. Scott began the very important work which he has 

 accomplished in this subject by helping the late distinguished palseo- 



