PROCEEDINGS OF 

 THE EOTAL SOCIETY. 



vol. lxviii. No. 449. 



CONTENTS. 



FAG-B 



The Mechanism of the Electric Arc. By (Mrs.) Hertha Ayrton. Com- 

 municated by Professor Perry, E.R S 410 



Report of Magnetical Observations at Falmouth Observatory for the Year 



1900 415 



The National Physical Laboratory. Report on the Observatory Department 



for the Year ending December 31, 1900 . . . " . . . .421 



The Stability of a Spherical Nebula; By J. H. Jeans, B.A., Scholar of 

 Trinity College, and Isaac Newton Student in the University of Cam- 

 bridge. Communicated by Professor G-. H. Darwin, E.R.S. . . . 454 



The Spectrum of r\ Argus. By Sir David Gill, K.C.B., LL.D., F.R.S., 



H.M. Astronomer at the Cape (Plate 4) 456 



Croonian Lecture. — Studies in Visual Sensation. By C. Lloyd Morgan, 



F.R.S., Principal of University College, Bristol 459 



The Yellow Colouring Matters accompanying Chlorophyll and their Spectro- 

 scopic Relations. Part II. By C. A. Schunck. Communicated by 

 Dr. E. Schunck, F.R.S. (Plates 5, 6) 474 



Price Four Shillings. 



September 12, 1901. 



