Planes. 
PROFESSOR CAYLEY ON CUBIC SURFACES. 
269 
Section IV=12-2C a . 
Equation WXZ-}-Y 2 (yZ+SW) + («, b, c, <T£X, Y) 3 =0. Article Nos. 73 to 84. 
3. The diagram of the lines is 
Lines. 
Co h oj ta 
■— • 
[ 0 ] 
ir 
22 ' 
33' 
44' 
12 
13 
14 
23 
24 
34 
1 ' 2 ' 
1'3' 
1'4' 
2'3' 
2'4' 
3'4' 
12.34 
13.42 
14.23 
1x2= 2 
Plane touching along 
axis. 
Planes through axis, 
each containing a ray 
of the one node and 
a ray of the other 
node. 
12x2 = 24 
_3xl = _3 
>0 45 
o a o b a- 
Biradial planes, each 
containing two rays 
of the one node or 
two rays of the other 
node. 
Planes each containing 
three mere lines. 
