REDUCTION OF CURRENT RECORDS 75 
° 
Cc He 77 eKe, aS 
/ \ 
SUNS 
180° 
PTO) 
FIGURE 32.—Graphic solution of formula (5). 
constituent is especially useful in the preparation of a table for obtaining such values. 
This formula also may be deduced from the derivative formula (4) after equating the 
same to zero. 
Let R=the ratio H,/H,, and D=difference K,—K,, 
Then for (4) we have 
sin 2(7—K,,) + H?/H? sin 2(T—K,—K,+K,) 
=sin 2(7—K,)+R? sin 2(T—K,,— D) 
R? sin 2D 
SERCO SRO 1D) x tmaerrmin ae oh trier gee gre ec era ee (8) 
tan 2(7T—K,) = 
For a maximum velocity the quadrant for the angle 2(7—K,,) will be determined by 
the signs of the numerator and denominator of the above fraction, which will be the 
same respectively as for the sine and cosine of the angle. For a minimum velocity the 
signs will be reversed. 
878447°—50—6 
