Xiv CONTENTS. 



Department of Cosmical Physics. 



Page 



1. Is our Climate Changing ? By Sir John W. Moore, M.A., M.D 623 



2. A Comparison of the Changes in the Temperature of the Waters of 



the North Atlantic and in the Strength of the Trade Winds. By 

 Commander M. W. C. Hepworth, C.B., R.N.R 625 



3. Temperature Conditions in Scottish Lochs. By E. M. Wedderburn, 



F.R.S.E 626 



4. The Constants of the Limar Libration. By F. J. M. Stratton 626 



5. Investigations on the Electrical State of the Upper Atmosphere. 



By W. Makower, Margaret White, and E. Marsden 627 



TUESDAY, SEPTEMBER 8. 

 Department of Mathematics. 



1. *Apphcations of Quaternions to Problems in Physical Optics. By 



Professor A. W. Conway '. 627 



2. *0n a GenoraUsation of the Question in Probabilities known as ' Le 



Scrutin de Ballotage.' By Major P. A. MacMahon, F.R.S. . .' 627 



3. On Conformal Transformations of a Space of Four Dimensions and 



their Apphcation to Geometrical Optics. By H. Bate]vl\n 627 



4. On the Extension of Optical Ideas to General Electromagnetic Fields. 



By Professor E. T. Whittaker, Sc.D., F.R.S 629 



5. *Distribution of Electricity on a Moving Sphere. By Professor A. W. 



Conway 629 



6. Tlie Theory of Solids movijig in an Incompressible Fluid. By Pro- 



fessor F. PxTRSER, F.T.C.D 629 



7. On the Analysis of Projection. By Professor R. W. Genese, M-A 632 



Department of General Physics. 



1. A Suggestion Avith regard to the Meaning of Valency. By H. Bateman 634 



2. *Secondary Radiation. By Professor J. A. McClelland 635 



3. *The Scintillations of Zinc Sulphide. By Professor E. Rutherford, 



F.R.S 635 



4. A Determination of the Rate of Evolution of Heat by Pitchblende. 



By Horace H. Poole 635 



5. The Grating Spectrum of Radium Emanation. By T. Royds, M.Sc. . . 635 



6. *Photogi'aphs of Arc Spectra of Metals under Pressure. By Dr. W. G. 



DUFFIELD 636 



7. Secondary Effects in the Echelon Spectroscope. By H. Stansfibld, 



B.Sc 636 



8. Further Experiments on the Constitution of the Electric Spark. By 



T. Royds, M.Sc .637 



Department of Cosmical Physics. 



1. On New Methods of obtaining the Spectra of Flames. By G. A. 



Hemsalech, M.Sc, D.Sc 638 



2. Polar Lines in Arc Spectra. By Dr. W. G. Duffield 638 



3. *The Zeeman Effect in Sun-spots. By Professor J. Larmor, Sec.R.S. . . 639 



