116 



Trans. Acad. Sci. of St. Louis. 



This is shown and the method of plotting with the use of 

 three axes is plainly evident from fig. 5. 



The surface used is thus bounded by the lines AD, DB, 

 BC and CA. 



Fig. 5 



Series Dynamo Surface- The Condition of Power 

 Equal to a Constant is Shown. 



If we wish the relation between the variables for the 

 condition of constant power it may be gotten as follows: — 



Let Ei = a constant = d = 28400 



(14) Ei = 28400 



from equations (4) and (14) 



See fig. 5 OP. 



d db 



(15) 



av a\ 



= 4,060,000 , 16240 

 n i* + i 



See fig. 5 LM 



