IV CONTENTS OF VOL. XIX. SIXTH SERIES. 



Page 



Dr. Eobert A. Houstoun on the Damping of Long Waves in 



a Eectangular Trough 205 



Proceedings of the Geological Society : — 



Messrs. E. H. Eastall and J. Eomanes on the Boulders 



of the Cambridge Drift 206 



Mr. A. M. Finlayson on the Nephrite and Magnesian 

 .Rocks of the South Island of New Zealand 207 



NUMBEE CX.— FEBEUAEY. 



Prof. E. A. Millikan on a New Modification of the Cloud 

 Method of Determining the Elementary Electrical Charge 



and the most Probable Value of that Charge 209 



Dr. J.W.Nicholson on the Asymptotic Expansions of Bessel 



Functions 228 



Mr. F. E. Smith on Cadmium Amalgams and the Weston 



Normal Cell. (Plate III.) 250 



Dr. J. W. Nicholson on the Bending of Electric Waves 



round the Earth 276 



Mr. A. S. Eussell on some Variations observed in Electro- 



scopic Measurements and their Prevention 278 



Mr. T. Eoyds : Further Experiments on the Constitution of 



the Electric Spark. (Plate IV.) 285 



Mr. E. W. B. G-ill on the Electrical Effect of the Ultra-Violet 



Spectrum « 290 



Mr. F. J. Jervis-Smith on an Optical Method of Eeading the 



Torsional Angle of a Eotating Shaft 300 



Sir J. J. Thomson on a Theory of the Structure of the 

 Electric Field and its Application to Eontgen Eadiation 



and to Light 301 



Mr. Horace H. Poole on the Eate of Evolution of Heat by 



Pitchblende 314 



Prof. J. Joly on Pleochroic Halos 327 



Notices respecting New Books : — 



H. Bouasse's Cours de Physique 331 



Eesults of Observations made at the Coast and Geodetic 

 Survey Magnetic Observatory at Cheltenham, Mary- 

 land, 1905 and 1906 * 331 



C. W. Eaffety's Introduction to the Science of Eadio- 



activity 331 



Proceedings of the Geological Society : — 



Mr. O. T. Jones on the rlartfell-Yalentian Succession 

 around Plynlimon and Pont Erwyd (North Cardigan- 

 shire) . . . 332 



