Vlll CONTENTS OF VOL. XL. SIXTH SERIES. 



Page 

 Dr. Megh Nad Saha on Elements in the Sun. (Paper B.) . . 809 

 Proceedings of the Geological Society i — 



Mr. E. D. Oldham on a Model to illustrate the Origin 



of Mountain Ranges 825 



Mr. J. A. Douglas on Geological Sections through the 

 Andes of Peru and Bolivia: II. From the Port of 

 Mollendo to the Inambari River 826 



Index 827 



PLATES. 



I. Illustrative of Dr. P. D. Foote and Dr. W. F. Meggers's 



Paper on Atomic Theory and Low Voltage Arcs in Caesium 

 Vapour. 



II. Illustrative of Dr. F. B. Young, Mr. H. Gerrard, and 

 Mr. W. Jevons's Paper on Electrical Disturbances due to 

 Tides and Waves. 



III. Illustrative of Prof. W. L. Bragg's Paper on the Arrangement 



of Atoms in Crystals. 



IV. Illustrative of Mr. G. P, Thomson's Paper on the Spectrum 



of Hydrogen Positive Rays. 

 V.-VII. Illustrative of Sub-Lieut. A. L. Williams's Paper on the 

 Electrical Conductivity of Copper fused with Mica. 

 VIII. & IX. Illustrative of Mr. G. A. Hemsalech's Paper on the Light 

 Radiations emitted by the Vapours of Magnesium, Copper, 

 and Manganese under the Selective Actions of Thermo- 

 chemical and Thermo-electrical Excitations. 

 X. Illustrative of Mr. L. C. Ja :kson's Paper on Variably Coupled 

 Vibrations. 

 XI.-XIII. Illustrative of Prof. Barton a.d Miss Browning's Paper 

 on Triple Pendulums with Mutual Interaction and the 

 Analogous Electrical Circuits. 

 XIV. Illustrative of Dr. F. W. Aston's Paper on the Mass- Spectra 

 of Chemical Elements. 

 XV. Illustrative of Prof. R. Whiddington's Paper on the Ultra- 

 Micrometer. 

 XVI. Illustrative of Prof. J. Joly's Paper on the Closure of Small 



Cavities in Rocks exposed to High Pressures. 

 XVII. Illustrative of Mr. F. 0. Toy and Dr. J. C. Ghosh's Paper 

 on the Absorption of Light by the Goldberg Wed^e. 



ERRATUM. 



For formula on page 212, line 11, read 



