CONTENTS OF VOL. XI 

 JUN 14 1907 S. 



J 



NUMf%E<LXXIII.-JANUAB^ 1907. 



Lord Kelvin on the Im^^QB^gl^^fie^^a Waves of Three 

 Classes : (1) from a Single Displacement; (2) from a Group 

 of Equal and Similar Displacements ; (3) by a Periodically- 

 Varying Surface-Pressure 1 



Messrs. K. Honda and T. Terada on the Change of Elastic 

 Constants of Ferromagnetic Substances by Magnetization. 



(Plates I.-V.) 36 



Prof. Bertram Hopkinson on the Measurement of Gas- 



Engine Temperatures. (Plate VI.) 84 



Dr. S. R. Milner on Surface Concentration, and the Formation 



of Liquid Films 96 



Prof. E. Rutherford on the Velocity and Energy of the 



a particles from Radioactive Substances 110 



Mr. G. F. C. Searle on the Impulsive Motion of Electrified 



Systems 118 



Dr. C. Chree : Auroral and Sun-spot Frequencies Contrasted. 149 



Dr. Otto Hahn on Radioactinium 165 



Mr. W. H. Patterson on the Carbon Cell . . . 181 



Notices respecting New Books : — 



Sir W. Huggins's The Royal Society, or, Science in the 



State and in the Schools 186 



Prof. H. A. Lorentz's Abhandlungen liber theoretische 



Physik 187 



Dr. R. Bornstein's Leitfaden der Wetterkunde. ....... 187 



J. F. Allen's Some Founders of the Chemical Industry . 188 

 Erich Marx's Die Geschwindigkeit der Rontgenstrahlen . 188 



NUMBER LXXIV.— FEBRUARY. 



Mr. G. A. Schott on the Electron Theory of Matter and on 



Radiation 189 



Lord Rayleigh on our Perception of Sound Direction 214 



