FIGURES OF CRYSTALS. 



417 



thus obtained, and from the point d 1 , draw the lines 

 requisite to complete the figure. 



To draw the Hexagonal Prism. 

 Fig-. 377. 







The size of the figure should be first determined. 

 Draw the lines a b, and if, parallel to each other. 

 From the point o in the line if, describe a circle 

 with a radius equal to the line h' g', which is to be 

 the front edge of the prism. Draw the chords jfg-, gh, 

 &c. and from the points e, f, g, h, i, k, draw the 

 oblique lines to the line a b ; and from the termination 

 of the oblique lines at that line, raise the several 

 perpendiculars shewn in the figure. To elevate the 

 back of the prism, take some quantity i 1 /, f ' m, on 

 the perpendiculars at i' and/ 7 ; draw the lines h 1 /, and 

 g' m, and complete the base by drawing parallels to 

 these and to k' e f , as shewn in the figure. Let us 

 suppose the height of the prism to be to its edge as 5 

 to 7; divide the edge h' g' into 7 equal parts, and 

 make h f h" equal to 5 of those parts. Then complete 

 the figure by drawing the upper terminal edges paral- 

 lel to the edges of the base. 



SG 



