﻿438 Prof. Lyle and Mr. Baldwin on Propagation of 



The specific resistance of each specimen was also measured. 



In the case of specimen A, after all the observations that 

 were deemed necessary for its full length had been taken, it 

 was shortened by successive steps by cut^ng off each time 

 equal lengths from both ends ; each reduced length was then 

 investigated for one frequency and one central flux. 



4. We now proceed to give the results of the different 

 experiments. 



For every series the Fourier characteristics of the mag- 

 netizing current w T ave and of the resultant flux wave at 

 different distances from the centrally placed magnetizing 

 solenoid will be given in tabular form, and curves will be 

 given showing how the phase, and the natural logarithm of 

 the amplitude, of the first harmonic of the resultant flux 

 varies as we pass along the specimen from the centre to the 

 end. In the tables will also be given for different points the 

 values of the leakage coefficient X x of the amplitude f x of the 

 first harmonic of the flux, where 



x'-x (q * p,; 



at the point ■£(# + #'), where x and x' are two adjacent points 

 at which f\ has been determined. By means of the last 

 expression the values of \ 1 have been calculated, and they 

 are placed in the tables between the two adjacent rows of 

 characteristics from which they have been obtained. 



In the tables T will represent the period of the alternating- 

 current and flux in any one experiment, x the distance from 

 the centre of the specimen (and of the magnetizing solenoid) 

 of the section across which the resultant flux F (in absolute 

 measure) passes, and C the magnetizing current used during 

 one series (also in absolute measure). 



No harmonics higher than the 5th will be given, though 

 they were determined in all cases, unless their amplitudes were 

 below one per cent, of the amplitude of the corresponding 

 first harmonic. 



The galvanometer circuit of the wave-tracer when search- 

 coil No. 3 was used had a very small time constant which 

 was allowed for. 



[Note. — The figures given in the tables are the results 

 from the individual experiments. No smoothing of values 

 has been resorted to, though a small error in the setting of 

 the search-coil would make a large error in the result.] 



