Waves along a Line of Negligible Leakage. 

 Table III. 



305 



The effect on the Attenuation of possible errors in the Ratios 

 of the Electrometer-throws. 



Ratios of electrometer- 

 throws with length of 

 line after electrometer 

 48 metres, and length 

 before 



Value of s 



where 



attenuation 



factor 



= 10-* 



per metre. 



Value of cr 

 where 



attenuation 

 factor 

 =«— <r 



per centim. 



Remarks. 



116 metres. 



65 metres. 



2-555 



2955 



0000566 



000001 30 ' Standard result. 



2-599 



2-980 



0000533 



( Result when each ratio 

 0-00001224 \ is increased by its pro- 

 | bable error. 



2-599 



2-930 



0000478 



[ First ratio increased and 

 0-0000110 \ second diminished by 

 1 probable error. 



2-511 



2-980 



0000655 



( First ratio diminished 

 0-0000149 j and second increased 

 [ by probable error. 



There are other possible causes of a discrepancy between 

 the two values of a. For example, any irregularity in the 

 spacing or diameter of the wires would lead to a slight re- 

 flexion at the place of its occurrence, thus making the line 

 behave towards the electric waves somewhat as a turbid or 

 translucent medium behaves towards light. But as great 

 care was taken in the spacing of the w^ires, no appreciable 

 effect is likely to have arisen from this cause. 



In conclusion I must thank Mr. Oliver Heaviside both for 

 the suggestion which initiated this investigation and for his 

 advice, ever freely given, during its continuance. 



I am also specially indebted to one of our advanced students, 

 Mr. Louis Lownds, for his able and painstaking assistance 

 throughout the work both in the experimental and theoretical 

 portions. 



Universitv College, Nottingham, 

 May 24, 1898. 



