* PROCEEDINGS OF THE ROYAL SOCIETY OP LONDON S e r ie s A CONTAINING PAPERS OF A MATHEMATICAL AND PHYSICAL CHARACTER. YOL. CYI. LONDON: Printed for THE ROYAL SOCIETY and Sold by HARRISON AND SONS, Ltd., ST. MARTIN’S LANE, PRINTERS IN ORDINARY TO HIS MAJESTY. D ecember, 1924. LONDON : HARRISON AND SONS, LTD., PRINTERS IN ORDINARY TO HIS MAJESTY, ST. m a r t in ’s LANE. CONTENTS ------ >oXXo«------ SERIES A. VOL. CVI. Minutes of Meetings, June 5, 19, 26 ; November 6, 13, 20, 1924. No. A 735.—July 1, 1924. PAGE The Non-Luminous Oxidation of Phosphorus in an Oxygen Atmosphere. By Lord Rayleigh, F.R.S.................................................................................................... * On the Absorption and Scattering of y-Rays. By N. Ahmad, M.Sc., Peteiliouse, Cambridge, and E. C. Stoner, B.A., Emmanuel College, Cambridge. Com­ municated by Prof. Sir E. Rutherford, F.R.S.......................................................... The 27-day Period (Interval) in Terrestrial Magnetic Disturbance. By the Rev. A. L. Cortie, S.J., D.Sc., F.Inst.P., Director, Stonyhurst College Observatory. Communicated by Dr. C. Chree, F.R.S. (Plate 1) .............................................. 19 An Automatic and Continuous Recording Balance. .(The Od6n-Keen Balance.) By John R. H. Coutts, Edward M. Crowther, Bernard A. Keen, and Sven Oden. Communicated by Sir John Russell, F.R.S.................................................. 33 Absorption of Lithium Vapour. By Prof. A. L. Narayan, M.A., D.Sc., and D. Gunnaiya, M.A. Communicated by Lord Rayleigh, F.R.S. (Plate 2) ....... 51 The Use of the Coherer to Investigate Adsorption Films. By William George Palmer, Fellow of St. John’s College, Cambridge. Communicated by Sir William Pope, F.R.S.................................................................................................... 55 The Band Spectrum of Hydrogen. By H. Stanley Allen, M.A., D.Sc., Professor of Natural Philosophy in the University of St. Andrews. Communicated by Prof. O. W. Richardson, F.R.S................................................................................... 69 An Experimental Study of the Viscous Properties of Water Vapour. By C. J. Smith, M.Sc., A.R.C.S., D.I.C., Demonstrator, Physics Department, Imperial College of Science and Technology. Communicated by Prof. H. L. Callendar, F.R.S.............................................................................................................................. 83 The Destruction of Rennin by Agitation : A Case of Catalysis at an Air-Liquid Interface. By Eric Keightley Rideal and Charles George Lewis Wolf. Com­ municated by Prof. Sir W. J. Pope, F.R.S............................................................... 97 No. A 736.—August 1, 1924. The Light of the Night Sky : Its Intensity Variations when Analysed by Colour Filters. By Lord Rayleigh, F.R.S........................................................................... 117 IV PAGE On the Luminescence of Nitrogen, Argon, and other Condensed Gases at very Low Temperatures. By J. C. McLennan, F.RS., Professor of Physics, and G. M. Shrum, Ph.D., University of Toronto. (Plate 3) .................................................. 138 The Nature and Artificial Production of Consonant Sounds. By Sir Bichard A. S> Paget, Bt. Communicated by Sir Wm. Bragg, F.R.S........................................... 150 On the Band-Spectra of Silicon Oxide and Chloride, and Chlorides of Carbon, Boron, and Aluminium. By W. Jevons, M.Sc., A.R.C.Sc., F.Inst.P., Lecturer in Physics, Artillery College, Woolwich. Communicated by Prof. H. C. Plummer, F.R.S. (Plate 4) ................. — .............................................................. 174 The Effect of Argon on Certain Spectra. By R. C. Johnson, B.A., B.Sc., Lecturer in Physics, and W. H. B. Cameron, B.Sc., Research Student, Queen’s University, Belfast. Communicated by T. R. Merton, F.R.S. (Plates 5 and 6) .................. 195 A Discontinuity in the Dehydration of Certain Salt Hydrates. By Edward Mortimer Crowther and John Reginald Horder Coutts. Communicated by Sir John Russell, F.R.S......................................................................... ............................ 215 No. A 737.—September 1, 1924. On the Drift of Spinning Projectiles. By J. W. Campbell, Ph.D., Assoc. Professor of Mathematics, University of Alberta, Canada. Communicated by Dr. J. S. Plaskett, F.R.S.............................................................................................................. 222 The Indirect Measurement of the Aqueous Vapour-Pressure of Capillary Systems by the Freezing-point Depression of Benzene. By Edward Mortimer Crowther and Amar Nath Puri, Soil Physics Department, Rothamsted Experimental Station. Communicated by Sir John Russell, F.R.S.................... 232 Activity Measurement by the Partition Method.—I. By Bernard Cavanagh, B.A., Balliol College, Oxford. Communicated by Prof. J. W. Nicholson, F.R.S......... 243 The Catalytic Action of Copper. Part IV.—The Periodic Variation of the Activity with Temperature of Reduction. By W. G. Palmer, Fellow of St. John’s College, Cambridge, and F. H. Constable, Strathcona Research Student of St. John’s College, Cambridge. Communicated by Sir William Pope, F.R.S. ... 250 The Elastic Stability of an Annular Plate. By W. R. Dean, B.A., Fellow of Trinity College, Cambridge. Communicated by Prof. G. I. Taylor, F.R.S. ... 268 The Homogeneous Thermal Decomposition of Nitrous Oxide. By C. N. Hinshelwood, Fellow of Trinity College, Oxford, and R E. Burk, Merton College, Oxford. Communicated by Prof. J. W. Nicholson, F.R S..................... 284 I’he Kinetics of the Interaction of Nitrous Oxide and Hydrogen. By C. N. Hinshelwood, M.A., Fellow of Trinity College, Oxford. Communicated by Prof. J. W. Nicholson, F.R.S.................................................................................... 292 Double Fourier Series of a Discontinuous Function. By E. C. Titchmarsh, lellow of Magdalen College, Oxford ; Senior Lecturer in Pure Mathematics m University College, London. Communicated by Prof. G. H. Hardy, F.R.S. 299 VT PAGE The Cataphotesis of Gas Bubbles in Water. By Thomas Alty, M.Sc. (Liv.), Ph.D. (Cantab.). Communicated by Sir Joseph Thomson, O.M., F.K.S........................ 315 Boundary Lubrication.—Further Consideration of the Influence of the Composition of the Solid Face. By Ida Doubleday. Communicated by W. B. Hardy, Sec.RS............................................................................................................................. 341 No. A 738.—October 1, 1924. The Influence of Atomic Arrangement on Refractive Index. By W. L. Bragg, F.R.S., Langworthy Pi’ofessor of Physics, Manchester U niversity...................... 346 A Theoretical Calculation of the Rhombohedral Angle of Crystals of the Calcite Type. By W. L. Bragg, F.R.S., Langworthy Professor of Physics, and S. Chapman, F.R.S., Beyer Professor of Mathematics, Manchester University ... 369 On Ultra-Violet Spectro-photometry. By T. R. Merton, F.R.S. (Plate 7) ........... 378 The Thermal Expansion of Crystals of Metallic Bismuth. By J. Keith Roberts, Ph.D. (Cantab.). Communicated by Sir Joseph Petavel, F.R.S............................ 385 On the Fine Structure of the Band-Spectra of Sodium, Potassium, and Sodium- Potassium Vapoui’s. By H. Grayson Smith, M.A. Communicated by Prof. J. C. McLennan, F.R.S...................................................................... ........................... 400 Elastic Waves at the Surface of Separation of Two Solids. By R. Stoneley, M.A., University of Leeds. Communicated by Prof. H. F. Baker, F.R.S..................... 416 Note on Vegard’s Theory of the Aurora. By R. d’E. Atkinson, B.A., Research Fellow, Hertford College, Oxford. Communicated by Prof. F. A. Lindemann, F.R.S............................................................................................................................... 429 On the Determination of Molecular Fields.—I. From the Variation of the Viscosity of a Gas with Temperature. By J. E. Jones, D.Sc. (Manchester), 1851 Exhibition Senior Research Student, Trinity College, Cambridge. Com­ municated by Prof. S. Chapman, F.R.S..................................................................... 441 On the Determination of Molecular Fields.—II. From the Equation of State of a Gas. By J. E. Jones, D.Sc., 1851 Exhibition Senior Research Student, Trinity College, Cambridge. Communicated by Prof. S. Chapman, F.R.S....................... 463 No. A 739.—November 1, 1924. The Lattice Points of a Circle. By J. E. Littlewood, F.R.S., and A. Walfisz. (With a Note by Prof. E. Landau) ........................................................................ 473 Studies of Co-ordination. Part I.—Absorption Spectra and Co-ordination of some Cupric Compounds. By Helen Somersby French and Thomas Martin Lowry, F R S ............................................................................................................................. 489 Perturbations of Harmonic Tidal Constants. By A. T. Doodson, Tidal Institute, University of Liverpool. Communicated by H. Lamb, F.R.S............................. 513 On the Possible Ellipticity of Saturn’s Ring. By G. R. Goldsbrough, D.Sc., Armstrong College, Newcastle-upon-Tyne. Communicated by Prof. T. H. Havelock, F.R.S................................................................................. 52g VI PAGE Some Relations between the Optical Spectra of Different Atoms of the Same Electron Structure. I —Lithium-like