S. L. Penfield — Crystal Drawing. 



65 



of the crystals may be fully 

 appreciated. Taking an- 

 other example ; it has 

 always seemed to the writer 

 that the clinographic pro- 

 jection of epiclote, figure 

 49, was poorly adapted for 

 showing the form of so sim- 

 ple a crystal. It represents 

 a combination lengthened 

 in the direction of the h 

 axis andjterminated by two 

 faces n (111), one of which, 

 however, in the position 

 adopted, happens to be 

 foreshortened to a line. 

 The accompanying ortho- 

 graphic projection, espec- 

 ially if studied in connec- 

 tion with a model, helps to 

 give an understanding of 



44 



46 



47 



48 



7h 



Pyroxene. Tremolite. Adular. 



the shape. A clinographic projection better adapted for giving 

 an idea of the development of the crystal is shown in figure 50. 

 -Fourth Series, Vol. XIX, No. 109.— January, 1905. 



Am. Jour. Sci. 

 5 



