PHILOSOPHICAL TRANSACTIONS 
OF THE 
ROYAL SOCIETY OE LONDON. 
Series A, Vol. 219. Pp. 1-135. 
[Plates 1-5 and Ap. 1-Ap. 3. Diagrams 1-6.] 
THE MAGNETIC RE-SURVEY OF THE BRITISH ISLES FOR 
THE EPOCH JANUARY 1. 1915. 
BY 
GEORGE W. WALKER, A.R.C.Sc., M.A., F.R.S., 
FORMERLY FELLOW OF TRINITY COLLEGE, CAMBRIDGE. 
AND 
APPENDIX 
A REPORT ON MAGNETIC DISTURBANCES IN 
NORTHAMPTONSHIRE AND LEICESTERSHIRE AND THEIR 
RELATIONS TO THE GEOLOGICAL STRUCTURE. 
BY 
ARTHUR HUBERT COX, M.Sc., Ph.D., F.G.S. 
(DRAWN UP AT THE REQUEST OF THE IRON-ORE COMMITTEE OF THE CONJOINT BOARD OF 
SCIENTIFIC SOCIETIES.) 
Printed and Published for the ROYAL SOCIETY by 
HAJHRISON AND SONS, 44^7, ST. MARTIN’S LANE, LONDON, W.C. 2, 
l^rintertf in ^dinars to Igiif 
1919. 
A 670. 
Price Fifteen Shillings. 
7.8.19 
