Magnetic Survey of the British 
for epoch P* January 1916. 
by G,W, Walker, Esq,, F.R.S. 
Isles 
hKKU.AM) 
JHJ.ANJJS 
LINES OF EQUAL VERTICAL COMPONENT 
Terrestrial line* 
Dtstnci lines 
ta 
ULANUS 
4«CIOO 
I 
