Waves along a Line of Negligible Leakage. 

 Table II. 



301 



Summary of Data and Results of Experiments, with previous 

 result added for comparison. 



Lengths < 

 before 



jf Line 



after 



Electrometer 



=/ 2 . 



Ratios of 

 Throws 



The unknowns for 



which the equations 



were solved. 



Attenuation 



Constant, 



tr. 



Reflexion 



Coefficient 



at Oscillator,} 



P- 



Electrometer 



=, 



s. 



P 2 . 



metr 



es. 



metres. 













o 



c -a 

 £ c 



b| 



9 

 Q 



116 

 65 



48 

 48 



2555 ±0044 

 2-955+00254 



0-000566 



0-513 



00000130 



0-716 



n 



3 2 

















u e8 



o g 



117-5 

 65-0 



20 

 20 



2-41 ±0-04 

 2-744+0035 



1 0-000564 



0-4776 



00000130 



0-69 



18 5 



a) « 

















Discussion of Results. — Heaviside has shown* that for 

 electric waves along a pair of parallel leads the attenuation 

 factor is 



e —(R'/2Lo+K/28v)x ^ /]\ 



where R', K, L, and S are respectively the effective resistance 

 to the waves in use, the leakage conductance, the inductance, 

 and the permittance, all per unit length of the line, v is the 

 speed of light, x the space coordinate along the line, all units 

 being on the C.G.S. electromagnetic system. 

 This, for the present case, reduces to 



e -Wx/2Lv^ (2) 



since K/2Syisof the order one hundred-thousandth of R'/2Lu. 

 Now to obtain an approximate value of R', use Lord 

 Rayleigh's high-frequency formula f 



R' = RVW", (3) 



where R is the resistance to steady currents of length I of 

 the wire, « = Z/R= the conductivity per unit length of the 



* ' Electrical Papers,' vol. ii. p. 148, and elsewhere, 

 t Phil. Mag. May 1886, p. 390, equation (26). 



