Whitehead and Hill — Measurement of Self -Inductance. 157 



If, however, R' had to be altered, the observations were 

 regarded as separate and so worked out. 



It was not the purpose of the authors to measure inductance 

 to any great degree of accuracy, but to indicate the possibilities 

 of the methods. Resistances were measured only to about two 

 or three parts in ten thousand on the post office box, which 

 had a considerable temperature correction. Still it will be seen 

 that the determinations of L, except those of coil P, differ from 

 the mean by less than 3/10 per cent. 



The measurements *of coil P were among the first made with 

 this method, and the resistances were not measured with as 

 much care as in the case of the other coils. 









Table 



III. 













Oct. 24, 



1903. 







R„ 



E" 



r 



R, 



E' 



n 



L 



103-75 



103-67 



425-06 900-76 



870-9 



65*644 



•5722 henry 



a 



a 



a 



900-76 



870-9 



65-614 



•5725 " 



a 



a 



a 



948-23 



919*72 



65-763 



•5715 " 



a 



<.( 



a 



989-3 



961-7 



65-763 



•5737 " 



«' 



a 



a 



900-76 



870-94 



65-614 



•5723 " 



a 



u 



a 



948-23 



918-67 



65-614 



•5733 " 



a 



a 



a 



989-3 



Table IV, 

 Dec. 10, 



961-7 



Coil C. 

 1903. 



65-614 

 Mean 



•5749 " 

 •57291 " 



Temp 



R„ 



E" 



r 



E' 



E' 



n L (henrys^ 



16°-3C. 



99-907 



99-78 



968-8 1199-86 1088-6 63'288 1*3044 



After the elapse of some minutes. 



1199-86 1088-6 63*288 1'3044 









Dec. 



13, 1903. 









15°-0 



99-94 



99*42 



968-9 



1200*47 



1088*0 



62*366 



1*3055 



a 



a 



a 



a 



a 



a 



62-446 



1*3008 



a 



a 



(i 



ii 



a 



a 



62-259 



1*3047 



a 



a 



u 



a 



a 



a 



62*206 



1*3058 



Mean 1*30257 









Table V, Coil S. 















Nov. 13, 1903. 









R fl 



E" 



r 



E ; 



E' 



n 



L 



(henrys) 



100-0 



100-0 



425*06 



1815-5 



1767-2 



65*393 





1*0309 



it 



a 



n 



<e 



1766-67 



65*393 





1*0366 



ii 



a 



a 



1862-9 



1815*5 



65-688 





1*0303 



ii 



a 



a 



1904-0 



1856-96 



66-091 





1*0311 



it 



a 



a 



1904-0 



1856-96 



65*763 

 Mean 





1*0353 

 1*0329 



A.M. Jour. 



Sci.— 



Fourth Series, Vol. XIX, No. 110. 



—February 



1905. 



11 



