336 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



In this case the drop in potential about the rectifier was obtained from 

 the curve of current from molybdenite to copper of Figure 5. The 

 equation to this curve, within the limits employed in the calculations, 

 is approximately 



(10) e r = qi + rx/'s, in which q x = 3.8 volts and r x = 6470 ohms. 



These values substituted in an equation of the form of equation (7) 

 gave, since the exponential term was found to be negligible, 



(11) — i s = .72 X 10~ 3 sin (wt - 4.8) - .55 X lO" 8 . 



Computations from this equation gave the values of current recorded 

 in Table VII. 



TABLE VII. 



Computed Values of the Rectified Cycle. Lower Loop. 



The computed values of Tables VI and VII are plotted as the continuous 

 curve E, of Figure 7, along with the voltage-phase curve, which is the 

 dotted sine curve S. 



The data used in the computations are entirely independent of the 

 oscillograms, except that the amplitude of the voltage-phase cycle was 

 taken from oscillogram No. 1 or No. 2, and this value was used in de- 

 termining the self-inductance of the circuit. 



The agreement of the diagram of Figure 7 with the oscillograms Nos. 

 1 and 2 of the Plate is very striking, as regards both the form and the 

 absolute value of the curves. The agreement with oscillogram No. 2 is 

 a little better than with No. 1, and is within the limit of error of the 

 measurement of the photograph. No departure in amplitude or in 

 phase exists between the rectified cycle and the voltage-phase cycle 

 that is not accounted for by the inductance and resistance of the oscil- 

 lographic apparatus or by the current-voltage curves of the rectifier 

 with steady currents. 



