MODIFICATIONS. 



271 



The right Oblique-angled Prism. 

 Fig. 316. 



Decrements on the acute solid angles, are all comprised 

 within class b. 



1. Simple and mixed. 



E represents the middle plane. 



E . . the planes which intersect the 

 plane P parallel to a diagonal. 



P E . . . the planes which in the same 

 manner intersect the plane T. 



E p M. 



2. Intermediary. General symbol (B P Gr C q ). 



Decrements on the obtuse solid angles are all comprised 



within class a. 



The symbols representing the planes corresponding 

 in character with those above described, are, 



A. 



A. 

 P A. 



A p . 



(Cp Hr Bq). 



. 



