VI 



Pape 



On the Intensely Penetrating Rays of Radium. By Hon. R. J. Strutt, 

 Fellow of Trinity College, Cambridge. Communicated by Lord 

 Rayleigh, F.R.S 208 



No. 481.- August 31, 1903. 



On the Formation of Definite Figures by the Deposition of Dust. By 

 J. Aitken, F.R.S. (Abstract) 21 1 



Mean Results of Monthly Determinations of the Magnetic Elements at 

 the Valencia Observatory, Cahirciveen, lat. 51 56' N., long. 10 15' W. 

 By J. E. Cullum 211 



On the Measurement of the Diffusion of Salts in Solution. By J. C. 

 Graham. Communicated by Professor W. E. Ayrton, F.R.S 212 



Surface Flow in Crystalline Solids under Mechanical Disturbance. 

 By G. T. Beilby. Communicated by F. H. Neville, F.R.S. 

 (Plates 9 and 10)..! 218 



The Effects of Heat and of Solvents on Thin Films of Metal. By G. T. 

 Beilby. Communicated by F. H. Neville, F.R.S. (Plates 1113).... 226 



The " Hunting " of Alternating-Current Machines. By Bertram 

 Hopkinson, M.A. Communicated by Professor J. A. Ewing, F.R.S. 235 



No. 482. October 19, 1903. 



The Spectra of Metallic Arcs in an Exhausted Globe. By A. Fowler, 

 A.R.C.SC., F.R.A.S., and Howard Payn, F.R.A.S. Communicated by 

 Sir Norman Lockyer, K.C.B., LL.D., F.R.S. (Plate 14) 253 



The Phenomena of Luminosity and their possible Correlation with 

 Radio- Activity. By Professor Henry E. Armstrong, F.R.S., and 

 T. Martin Lowry, D.Sc 258 



Radiation in the Solar System : its Effect on Temperature and its 

 Pressure on Small Bodies. By J. H. Poynting, Sc.D., F.R.S., 

 Professor of Physics in the University of Birmingham. (Abstract).... 265 



The Theory of Symmetrical Optical Objectives. By S. D. Chalmers, B. A. 

 (Cantab.), M.A. (Sydney), St. John's College, Cambridge. Communi- 

 cated by Professor Laraior, Sec. R.S 267 



On the Discharge of Electricity from Hot Platinum. By Harold A. 

 Wilson, D.Sc., B.A., Fellow of Trinity College, Cambridge. Com- 

 municated by C. T. R. Wilson, F.R.S. (Abstract) 272 



The Properties of the Aluminium-Tin Alloys. By W. Carrick Anderson, 

 M.A., D.Sc., and George Lean, B.Sc. Communicated by Professor 

 H. A. Miers, F.R.S. (Plate 15) 277 



Cyanogenesis of Plants. Part III. On Phaseolunatin, the Cyanogenetic 

 Glucocide of Phuseohis lunatua. By Wyndham R. Dunstan, M.A., 

 F.R.S., Director of the Imperial Institute, South Kensington, and 

 Thomas A. Henry, D.Sc. (Lond.) 285 



The Differential Invariants of Space. By Professor A. R. Forsyth, Sc.D., 

 LL.D., F.R.S. (Abstract; 294 



The Ultra-violet Spectrum of Radium. By Sir William Crookes, F.R S. 

 (Plates 1C 18) 295 



