CONTENTS OF VOL. XLI 



(SIXTH SERIES). 



NUMBER CCXLL— JANUARY 1921. 



Pago 

 Mr. W. N. Bond on the Properties of Plastic Crystals of 



Ammonium Nitrate. (Plates I. & II.) 1 



Mr. D. L. Hammiok on Surface Energy, Latent Heat, and 



Compressibility 21 



Dr. N. W. McLachlan on the Effective Inductance, Effective 



Resistance, and Self-Capacity of Magneto Windings .... 33 

 Mr. E. H. Darnley on the Transverse Vibrations of Beams 

 and the Whirling of Shafts supported at Intermediate 



Points 81 



Prof. E. Slate on Electronic Energy and Relativity 96 



Dr. H. Bateman on an Electromagnetic Theory of Radiation. 107 

 Dr. H. Stanley Allen on the Angular Momentum and some 



Related Properties of the Ring Electron 113 



Mr. L. Simons on the Beta-Ray Emission from Thin Eilms 



of the Elements exposed to Rontgen Rays. (Plate III.)*. 120 

 Prof. Alex. M c Aulay on the Inertial Frame given by a 



Hyperbolic Space-time 141 



Sir George G-reenhill on the Newton-Einstein Planetary Orbit. 143 

 Prof. F. T. Edgeworth on the Genesis of the Law of Error. 148 

 Proceedings of the Geological Society : — 



Mr. G. W. Lamplugh on some Features of the Pleistocene 



Glaciation of England 158 



Mr. H. Crunden Sargent on the Lower Carboniferous 

 Chert-Formations of Derbyshire 160 



NUMBER CCXLIL— FEBRUARY. 



Miss D. Wrinch on an Asymptotic Formula for the Hyper- 

 geometric Function oA-i(s) 161 



Miss D. Wrinch on a Generalized Hypergeomelric Function 

 with n parameters 174 



Dr. R. A. lToustoun and Miss M. A. Dunlop : A Statistical 

 Survey of the Colour Vision of 1000 Students L86 



