﻿10 Prof. E. Taylor Jones on tlie most 



of the secondary circuit separately, and (B) the result 

 of their superposition. It will be seen that two positive 

 maxima in the oscillations agree at about £ = '0006 sec, 

 giving rise to the maximum secondary potential (596900 

 volts) at this time. Fig. 4 shows the square of the secondary 



Fiir. 4. 



t. 10 3 sec. 



Square of secondary potential. 



potential plotted against the time. This curve shows clearly 

 the peaked maxima and the flattened zeroes which are 

 characteristic of the 3/1 ratio. 



In Plate I. figs. 6 and 7 are shown photographic 

 records of the secondary potential wave obtained with the 

 oscillograph. In these curves the ordinates are proportional 

 to the square of the secondary potential, owing to the idio- 

 static connexion of the instrument, and these curves are 

 therefore directly comparable with fig. 4. The currents 

 interrupted when these photographs were taken were 1*5 

 and 2*0 amperes respectively*. It will be seen that the 

 greatest ordinates of the curves are proportional to the 

 squares of the currents. In period t, rate of decay, and form 

 the calculated curve of fig. 4 agrees well with the photo- 

 graphs. The photographic curves are perhaps rather more 



* The greatest spark-length for 2 amperes, between spark-balls 2 cm. 

 in diameter, was 18*2 cm. The external inductance being removed, and 

 the primary coil being still in its symmetrical position within the 

 secondary, the greatest spark-length at 2 amperes (C l = , 6 mfd.) was 

 12'8 cm. No sparks passed when the photographs shown were taken. 



t The time curve shown on the photographs has a period of 1/768 sec. 



