ITS MODIFICATIONS. 



Primary form. A doubly oblique prism. 

 * ' 



This class of prisms may be supposed to stand in 

 the same relation to the right oblique-angled prisms, 

 that the oblique rhombic prism does to the right 

 rhombic prism ; and the following modifications will 

 be better understood, by supposing a right oblique- 

 angled prism to become oblique from an acute or 

 an obtuse edge of the prism. This form will then be 

 readily perceived to vary from the oblique rhombic 

 prism, in the dissimilarity of its plane angles A, E, 

 I, and O, of its acute terminal edges B C, and of its 

 obtuse terminal edges D and F. 



The edges and angles of this class of prisms may 

 be designated by the same terms as have been used 

 for the corresponding ones of the oblique rhombic 

 prism. 



The individuals belonging to this class will differ 

 from each other in the inclination of P on M, P on T, 

 and M on T, and in the ratios of the edges D, H, 

 and F. 



Modifications. 



Class o. Obtuse solid angles O, replaced by single 

 planes. 



