MODIFICATIONS, 



265 



The right Square Prism. 

 Fig. 313. 



Simple and mixed decrements on the terminal angles. 



General symbol A, represents class a generally. 

 In this symbol p may be ^> 1. 

 or= 1. 

 or<1. 



Ifp =z I, an individual plane belonging to the 

 class is represented, whose three 

 edges would be respectively parallel 

 to the diagonals of the adjacent pri- 

 mary planes. This plane may, from, 

 its station in the series, be denomi- 

 nated the middle plane. 



p ^> 1, the planes represented would incline 

 more on P than the middle plane does. 

 p <^ 1, the planes represented would incline 

 more on the edge G. 



Simple and mixed decrements on the lateral angles. 



General symbol P A P , p being ^> 1. 



This symbol represents a series of planes belonging 

 to class by whose intersections with the planes M and 

 M', are parallel to the diagonals of those planes. 



