CONTENTS. 
(A) 
VOL. 218. 
List of Illustrations.page v 
Advertisement.. vii 
I. The Solar and Lunar Diurnal Variations of Terrestrial Magnetism. By 
S. Chapman, M.A., D.Sc., Fellow and Lecturer of Trinity College, Cam¬ 
bridge, and Chief Assistant at the Royal Observatory, Greenwich. Communi¬ 
cated by Sir F. W. Dyson, Astronomer Royal, F.R.S . page 1 
II. The Specific Heat of Aqueous Solutions, with Special Reference to Sodium and 
Potassium Chlorides. By W. R. Bousfield, M.A., K.C., F.R.S., and C. 
Elspeth Bousfield . . .119 
III. Bakerian Lecture, 1917 .—The Configurations of Rotating Compressible 
Masses. By J. H. Jeans, M.A., F.R.S .157 
IV. On the Propagation of Sound in the Free Atmosphere and the Acoustic 
Efficiency of Fog-Signal Machinery: An Account of Experiments Carried 
Out at Father Point, Quebec, September, 1913. By Louis Vessot King, 
M.A. [Cantab.), D.Sc. [McGill), Associate Professor of Physics, McGill 
University, Montreal. Communicated by Prof. Howard T. Barnes, 
F.R.S. .211 
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