PHILOSOPHICAL TRANSACTIONS 
OF THE 
ROYAL SOCIETY OF LONDON. 
Series A, Vol. 218. Pp. 1-118. 
. 
THE SOLAR AND LUNAR DIURNAL VARIATIONS OF 
TERRESTRIAL MAGNETISM. 
BY 
S. CHAPMAN, M.A., D.Sc., 
FELLOW AND LECTURER OE TRINITY COLLEGE, CAMBRIDGE, AND CHIEF ASSISTANT 
AT THE ROYAL OBSERVATORY, GREENWICH. ’ 
Printed and Published for the ROYAL SOCIETY by 
HARRISON AND SONS, 44-47, ST. MARTIN’S LANE, LONDON, W.C. 2, 
Printer^ m ©rtrutacy to Uflafrtfty. 
1919. 
A 561. 5.2.19. 
Price Seven Shillings and Sixpence. 
