Fig. 10. 
466 
Lord Kelvin on the Front and Rear of a 
=~ 
~~ BS 2 PY ~ 
he) 
br) 
[\ 
em 
0 
7 
Y 
[\ 
| 
0 
7 
/ 
a 
[\ 
V/ 
awa 
Weak 
Tailfand rear of leftward procession. 
[\ 
Vay 
er Owe 
VY 
0 
¥ 
VV) 
