ITS MODIFICATIONS. Ml 



The following modifications do not accord with the, 

 law of symmetry as defined in p. 77. 



Class g. Alternate solid angles replaced by tan- 

 gent planes. 



A regular tetrahedron would result from this 

 modification. 



Class h. Alternate solid angles replaced by three 

 planes resting on the primary planes. 



The series of new figures resulting from this class, 

 would be similar to those produced by class c of the 

 tetrahedron. 



Class i. Solid angles replaced by three planes, 

 each of which inclines unequally on the three adjacent 

 primary planes. 



The unequal inclination of each of the modifying 

 planes on the three adjacent primary planes, distin- 

 guishes this class from class 6, ea,ch plane of which 

 inclines equally on two of the adjacent planes, and 

 unequally on the third plane. 



The character of this class is similar to that of 

 class tf, if we suppose the alternate three only of the 

 modifying planes to be produced on each solid angle. 



Class k. Edges replaced by single planes inclining 

 at unequal angles on the adjacent primary planes, 

 and bearing the same analogy to class f, that class i 

 does to class d. 



A series of dodecahedrons with pentagonal planes 

 would result from this class of modifications, but 



