36 



Prof. E. Taylor Jones on Electrical 



In Table II. are given the values of the frequencies ?? l5 n 2 , 

 of T and T', the damping coefficients k 1 and k 2 , ft, and the 

 phase angles 8, 8' in degrees, for the four cases. 











Table II. 













n x . 



n . 



T x 10 4 . 



T'xlO*. 



K 



K 



f (3xl0 3 . 



d. 



8*. 



I.... 



542-2 



882-7 



29851 



1-8030 



80-21 



169-1 



-707 



1-81 



2-95 



II.... 



582-8 



905-0 



2-7307 



1-7585 



77-50 



171-8 



-233 



2-08 



3-24 



III.... 



527-0 



814-7 



30201 



1-9535 



77-24 



172-0 



-240 



2-36 



3-651 



IV.... 



560-3 



844-4 



2 8405 



1-8847 



76-16 



173-1 



+ 1-79 



2475 



3-743 



The primary current, / , was taken as 5*5 amperes, and 

 values of the secondary potential, 2V 2 , were calculated from 

 (3) for various values of t up to about *008 second. For 

 the purpose of comparison with the photographs the values 

 of 2Y 2 were squared and the results plotted in curves. 

 Figs. 1, 2, 3, 4 show the curves so obtained for the four 

 cases, the abscissae representing the time in thousandths of a 

 second measured from the moment when the primary circuit 

 was broken, and the ordinates one millionth of the square of 

 the potential-difference in volts of the plates of the secondary 

 condenser. 



In obtaining the photographs, the primary condenser was 

 connected directly across the terminals of the primary coil 

 whose circuit contained also a battery and the mercury break 

 described above. The terminals of the secondary coil were 

 connected to the leyden-jar and to the electrometer. The 

 curve was photographed three or four times on each plate, 

 this being moved vertically in its own plane between the 

 exposures. In addition the two spots were photographed in 

 a number of positions in order to obtain the ratio of their 

 average velocities in any portion of the curve. The primary 

 current was not measured before each discharge, but before 

 and after a group of several discharges ; in the four cases 

 here considered the value so obtained was 5'5 amperes, but 

 there might possibly have been small variations during each 

 group of discharges which were not recorded. 



PL I. figs. 5, 6, 7, 8 show the photographs obtained with 

 the coils and condensers specified in Table I., the lower 

 wave -curve in each representing the oscillations of a 



