VI CONTEXTS OF VOL. XX. — SIXTH SERIES. 



NUMBEE CXVIIL— OCTOBER. 



Pago 

 Prof. 0. W. Richardson and Mr. E. R. Hulbirt on the Specific 



Charge of the Ions emitted by Hot Bodies. — II 545 



Prof. W. M. Thornton : The Eye as an Electrical Organ . . 560 

 Dr. H. Stanley Allen on the Photoelectric Fatigue of Metals. 504 

 Mr. A. E. Garrett on the Positive Electrification due to 



Heating Aluminium Phosphate 573 



Dr. Alexander Russell on the Convection of Heat from a 



Body cooled by a Stream of Fluid 591 



Dr. J. W. Nicholson on the Accelerated Motion of an Electri- 

 fied Sphere G10 



Prof. E. Goldstein on Threefold Emission-Spectra of Solid 



Aromatic Compounds Gl 9 



Mr. H. Bateman on the Relation between Elect romagnetism 



and Geometry 023 



Dr. J. E. Mills on Molecular Attraction 629 



Dr. S. R. Milner on the Series Spectrum of Mercury G3G 



Prof. J. H. Jeans on the Analysis of the Radiation from 



Electron Orbits '. 642 



Mr. G. II. Berry on the Pianoforte Sounding-Board. (Plate 



XII.) 652 



Mr. W. Sutherland on the Mechanical Vibration of Atoms . G57 

 Prof. E. Taylor Jones and Mr. I). E. Roberts on Musical Arc 



Oscillations in Coupled Circuits. (Plate XIII.) 660 



31 r. Robert E. Baynes : Note on Mr. Bateman's Paper on 



Earthquake- Waves 664 



Dr. R. 1). Kleeman on the Equation of Continuity of the 



Liquid and Gaseous States of Matter 665 



Prof. H. S. Carslaw on the Scattering of Waves by a Cone. . 690 

 Dr. Hans Geiger and Prof. E. Rutherford on the Number of 



a Particles emitted by Uranium and Thorium and by 



Uranium Minerals 691 



Prof. E. Rutherford and Dr. H. Geiger on the Probability 



Variations in the Distribution of a Particles : with a Note 



by H. Bateman 698 



Prof. R. W. Wood on a New Radiant Emission from the Spark. 



(Plate XIV.) 707 



Prof. R. W. Wood : Some Experiments on Refraction by 



non-homogeneous Media. (Plate XIV. fig. 10.) 712 



Dr. G. W. C. Kaye on a Method of Counting the Rulings of 



a Diffraction Grating. (Plate XV.) 714 



Dr. G. W. C. Kaye on the Expansion and Thermal Hysteresis 



of Fused Silica 718 



Sir G. Greenhill on Pendulum Motion and Spherical Trigo- 

 nometry 728 



Prof. E. G. Coker on the Optical Determination of Stress . . 740 



Sir J. J. Thomson on Rays of Positive Electricity 752 



Prof. A . Trowbridge on a Vacuum Spectrometer. (Plate XVI.) 768 

 Prof. R. W. Wood on the Echelette Grating for the Infra- 

 Red. (Plate XVII.) 770 



