VI 



CONTENTS OF VOL. XXXII. SIXTH SERIES. 



NUMBER CXCL— NOVEMBER. 



Page- 

 Mr. S. Ratner on the Mobility of the Negative Ion . 441 



Mr. S. G. Starling on the Equilibrium of the Magnetic 



Compass in Aeroplanes 461 



Prof. H. S. Carslaw on Napier's Logarithms : the Deve- 

 lopment of his Theory 476 



Dr. L. Silberstein on Multiple Reflexion 487 



Dr. Manne Siegbahn and Dr. Einar Eriman on an X-Ray 



Vacuum Spectrograph 494 



Dr. Einar Eriman on the High-Erequency Spectra (L-Series) 



of the Elements Lutetium-Zinc. (Plate XL) . , 497 



Messrs. E. B. AVood, 0. A. de Long, and K. T. Compton 



on Diffusion Cells in Ionized Gases 499 



Dr. L. Vegard on Results of Crystal Analysis. — III. 



(Plate XII.) 505 



Prof. A. Ogg and Mr. F. Lloyd Hopwood on a Critical Test 

 of the Cry stall ographic Law of Valency Volumes : a Note 

 on the Crystalline Structure of the Alkali Sulphates .... 518 

 Notices respecting New Books : — 



Alfred A. Robb's A Theory of Time and Space 526 



Proceedings of the Geological Society : — 



Mr. Arthur Holmes on the Tertiary Volcanic Rocks of 



Mozambique 526 



Dr. A. S trah an on Cores from borings in Kent 527 



Mr. E. P. Mennell on the Geology of the northern 

 margin of Dartmoor 528 



NUMBER CXCIL— DECEMBER. 



Lord Rayleigh on Convection Currents in a Horizontal Layer 

 of Eluid, when the Higher Temperature is on the Under 

 Side 529 



Mr. C. W. Raffety on some Investigations of the Spectra of 

 Carbon and Hydrocarbon. (Plate XIII.) 543 



Mr. A. P. Carman on the Collapse of Short Thin Tubes. 

 (Plate XIV.) 559 



Dr. C. B. Bazzoni : Experimental Determination of the 

 Ionization Potential of Helium 566 



Mr. H. Jeffreys on the Compression of the Earth's Crust in 

 Cooling 575 



Messrs. Miles Walker and W. Witcomb Stainer : An Inquiry 

 into the Possible Existence of Mutual Induction between 

 Masses 592 



