CONTENTS. 







(A) 

 VOL. 220. 



List of. Illustrations . . page v 



Advertisement vii 



I. Tidal Friction in the Irish Sea. By G. I. TAYLOR, M. A. Communicated by 



Sir NAPIER SHAW, F.R.S. page 1 



II. Electromagnetic Integrals. By Sir G. GREENHILL, F.R.S 35 



III. BAKERIAN LECTURE, 1918. Experiments on the Artificial Production of 



Diamond. By the Hon. Sir CHARLES ALGERNON PARSONS, K.C.B., 

 F.R.S. 67 



IV. The Pressure upon the Poles of the Electric Arc. By W. G. DUFFIELD, D.Sc., 



Professor of Physics, Captain, Royal Air Force, THOS. H. BURNHAM, B.Sc., 

 and A. H. DAVIS, B.Sc., Post-Graduate Students in Physics, University 

 College, Reading. Communicated by Prof. O. W. RICHARDSON, F.R.S. . 109 



V. On Intensity Relations in the Spectrum of Helium. By T. R. MERTON, D.Sc., 



Lecturer in Spectroscopy , University of London, King's College, and 

 J. W. NICHOLSON, F.R.S., Professor of Mathematics in the University of 

 London 137 



VI. The Scattering of Plane Electric Waves by Spheres. By T. J. I' A. BROMWICH, 



Sc.D.,F.R.S. 175 



a -J 



