GRAPHICAL ALGEBRA 



Fig. 76. Projection of a vector. 



A. Field of given vector (F, ip) represented by intensity-curves 

 F = 6, 7, 8, . . . (fine) and isogons <p = 8, 4. o, 60 . . . (heavy). 



B. Isogons of angle o =52, 56, 60, . . . 



C. Isogons of angle a of the angles and of the difference <p a =16, 

 12,8,. . . (stippled). 



D. Isogons ipa, intensity-curves F, and intensity-curves A =1,2,3, 

 ... of projection derived by first of tables K. 



E. Field of projection (.4, a) represented by intensity-curves -4 and 

 isogons a. 



