■ 
PHILOSOPHICAL TRANSACTIONS 
OP THE 
ROYAL SOCIETY OP LONDON. 
Series A, VOL. 212, pp. 299-337. 
THE EFFECT PRODUCED BY AN OBSTACLE ON A TRAIN OP 
ELECTRIC WAYES. 
BY 
H. M. MACDONALD, F.R.S 
UNIVERSITY OF ABERDEEN. 
LONDON: 
PUBLISECED BY THE ROYAL SOCIETY, 
AND SOLD BY HAEEISON AND SONS, ST. MAETIN’S LANE. 
DULAU AND CO., LTD., 37, SOHO SQUARE, W. 
FEIEDLANDEE AND SON, BERLIN. 
1912. 
A 493. 
Price Two Shillings. 
13.11.12 
