[334 
334] 
NOTE ON THE THEORY OF CUBIC SURFACES. 
139 
ES. 
496.] 
m, viz. each of 
irface in three 
i + B Y 3 = 0 are 
the equation of 
Dregoing linear 
oint of contact a 
with three double 
angent plane such 
ot in general any 
point. A surface 
ing the surface in 
a ‘ tritom’ tangent 
a tritom tangent 
singularity is sibi- 
al surfaces. 
18—2