CONTENTS. Xi 



Page 



2. The Essentials of a Machine for the Accurate Measurement of Celestial 

 Photographs. By A. R. Hinks, M.A 541 



3. Note on the Singkep Commutator. By David P. Todd 641 



4. The Drift in Longitude of Groups of Faculae on the Sun's Sui-face. By 



the Rev. A. L. Cortie, S.J., F.R.A.S 542 



5. On an Exceptional Case in the determination of the Constants of a Photo- 



graphic Plate from known Stars. By Professor H, H. Tttrner, F.R.S. 543 



6. "On the Position of a Planet beyond Neptune. By G. Forbes, F.R.S. ... 543 



SATURDAY, SEPTEMBER 14. 

 Department I. — Mathematics. 



*A joint Discussion with Section L on the Teaching of Mathematics, opened 

 by Professor John Perry, F.R.S 543 



Department II. — Physics. 



1. Report on Radiation in a Magnetic Field (p. 39) 544 



2. Note on a Method of determining Specific Heats of Metals at Low Tem- 

 peratures. By T. G. Bedford, M. A., and C. F. Green, M. A 544 



3. A New Gauge for Small Pressures. By Professor Edward W. Morley 

 and Charles F. Brush 544 



4. The Transmission of Heat through Water Vapour. By Charles F. 



Brush and Professor Edward W. Morley 546 



5. Comparison of the Constant Volume and Constant Pressure Scales for 

 Hydrogen between 0° C. and —190° 0. By Morris W. Travers, D.Sc, 

 and George Senier, B.Sc 546 



6. Note on the Variation of the Specific Heat of Water. By Professor 



H. L. Callendar, F.R.S. (p. 34) 547 



7. The Laws of Electrolysis of Alkali Salt Vapours. By Harold A. 



Wilson, D.Sc, M.Sc, kA '. 547 



8. Preliminary Note on the Theory of the Lippmann Electrometer and 



related Phenomena. By F. G. Cottrell 548 



9. *Effect of Non-Electrolytes on the Lippmann Electrometer Curve. By 



J. A. Craw 549 



10. ^Determination of the Surface Tension of Mercury by the Method of 



Ripples. By J. A. Craw 549 



11, *The Potential Differences of AUotropic Silver. By J. A. Craw 549 



MONDA Y, SEPTEMBER 16. 

 Department I. — Mathematics. 



1. Report on Tables of certain Mathematical Functions (p. 64) 549 



2. A Criterion for the Recognition of the Irregular Points of Analytic 

 Functions. By Professor Mittag-Lefeler, Foreign Member R.S 549 



3. Poincar^'s Pear-shaped Figure of Equilibrium of Rotating Liquids By 



G. H. Daewin, F.R.S 550 



