Vol,. 6, 1920 PHYSICS: A. G. WEBSTER 319 
3 
-2 
1 
X. — 
0 
10 
1 
20 
1 
3o 
1 
4 
0 
30cn, 
1 
with about the same degree of accuracy as it was confirmed by these re- 
sults more than four years ago. Professor Stewart has also given a theo- 
retical treatment that is an improvement on mine. We shall see whether 
it agrees better with the observations. The formulae I have used in cal- 
culating these curves are : 
In cylinder P sin ^ cos h% 
^ = ^7~"' 
Yo COS kl 
In cone = P sin kir — Tq + l3)/r, 
— c 
> 
< 
r 
> 
2 
N 
— ^ 
\ 
\ 
1 
— V 
N 
/ 
/ 
> 
\ 
; 
i 
' ^< 
> — ( 
0 
>^ 
\ 
Y 
— /- 
/ 
r 
10 
1 
20 
1 
1 
50cm 
1 
, 60 
1 
7 
? 
80 
1 
1 
lOOcm 
/ 
0 
# 
