22 Proceedings of the Royal Society of Victoria. 



As the whole behaviour of the transformer is to be evolved 

 from the no-load readings for Ci, Pj, and Ej, and the full load 

 reading of E.^, it is necessary that these should be obtained with 

 accuracy. 



The figures for C^ and Pj given in the record of the test were 

 probably obtained very near the zeros of the scales of the 

 ammeter and wattmeter used, so instead of relying on single 

 readings 1 obtained the no-load values of Cj and Pj by plotting 

 a few of the readings for them near no-load against the output, 

 and taking the values given by the points where the curves 

 obtained intersect the no-load axis. 



In this way I find that Cj at no-load = .058 amp. and P^ = 

 110 watts, which values give the same power factor, .79, as 

 Fleming obtained. 



It will be seen on inspection of the following table, that the 

 agreement between the values I have calculated and those 

 observed by Fleming is remarkably close. A very slight modifi- 

 cation or correction of the primary wattmeter readings, which 

 the recorded values of the power factor seem to suggest, would 

 make the agreement almost perfect when allowance is made for 

 the inevitable variations from mathematical accuracy of any 

 series of observations. 



TABLE I. 



Compai'ison of the measured values of the variables obtained in 

 a test by Fleming of a VYestinghouse transformer with values 

 theoretically calculated by the author from no-load values and 

 voltage drop. 



Power, 6500 watts. Frequency, 82.5 periods per second. 



ri = 5.95 ohms; ^3 = 0.0108 ohms, at 96'F. 



-r-, -../Nrv 1. -n riOl volts at no-load 



E, = 2400 volts; E,= |gg g ^^^j^^ ^^ ggg^ ^^^^^^ 



Ti = 6950, T,=6780, Sin8 = 0.79, -' = 23.76, [ 

 A-i + x, = 0.003 J 



