﻿Audibility 
  Factor 
  of 
  a 
  Shunted 
  Telephone. 
  487 
  

  

  of 
  gravitation 
  on 
  the 
  velocity 
  of 
  the 
  planets; 
  or, 
  if 
  preferred,, 
  

   the 
  same 
  thing 
  may 
  be 
  expressed 
  iri 
  Walker's 
  phraseology. 
  

  

  In 
  this 
  last 
  case 
  the 
  motion 
  of 
  the 
  sun 
  can 
  have 
  no 
  influence 
  

   on 
  the 
  perihelion 
  of 
  Mercury, 
  and 
  the 
  observed 
  excess 
  must 
  

   be 
  ascribed 
  either 
  to 
  outside 
  causes, 
  such 
  as 
  the 
  mass 
  or 
  

   resistance* 
  of 
  the 
  Zodiacal 
  Light, 
  or 
  to 
  the 
  laws 
  of 
  relative 
  

   motion. 
  In 
  my 
  paper 
  only 
  -J 
  of 
  the 
  observed 
  excess 
  f 
  is 
  

   given 
  by 
  the 
  relative 
  motion; 
  and 
  the 
  difficulty 
  is 
  to 
  bring 
  

   it 
  up 
  to 
  the 
  required 
  amount 
  without 
  extravagant 
  or 
  ad 
  hoc 
  

   assumptions. 
  Walker's 
  investigation 
  appears 
  rather 
  to 
  em- 
  

   phasize 
  this 
  difficulty. 
  Nevertheless 
  Einstein's 
  generalized 
  

   relativity 
  theory 
  gives 
  the 
  precise 
  value 
  required 
  without 
  

   any 
  arbitrary 
  constants. 
  It 
  may 
  perhaps 
  be 
  said 
  that 
  the 
  

   factor 
  6 
  (or 
  3) 
  must 
  be 
  implicitly 
  contained 
  in 
  the 
  assumptions 
  

   of 
  his 
  theory. 
  I 
  suppose 
  that 
  the 
  results 
  of 
  any 
  theory 
  are 
  

   implicitly 
  contained 
  in 
  its 
  postulates; 
  so 
  I 
  cannot 
  deny 
  that 
  

   the 
  factor 
  6 
  is 
  concealed 
  in 
  Einstein's 
  Principle 
  of 
  Equi- 
  

   valence 
  — 
  " 
  that 
  it 
  is 
  impossible 
  by 
  any 
  experiment 
  to 
  dis- 
  

   criminate 
  between 
  a 
  gravitational 
  field 
  and 
  a 
  field 
  of 
  force 
  

   (such 
  as 
  the 
  centrifugal 
  force) 
  arising 
  from 
  a 
  transformation 
  

   of 
  the 
  coordinates 
  of 
  reference." 
  But 
  at 
  least 
  it 
  is 
  cieverlv 
  

   camouflaged 
  ! 
  Many 
  pages 
  of 
  analysis 
  are 
  required 
  to 
  

   obtain 
  the 
  result 
  for 
  Mercury, 
  and 
  I 
  do 
  not 
  think 
  any 
  simple 
  

   interpretation 
  of 
  the 
  occurrence 
  of 
  the 
  factor 
  can 
  be 
  given 
  

   at 
  present. 
  

  

  LVII. 
  On 
  the 
  Relation 
  of 
  the 
  Audibility 
  Factor 
  of 
  a 
  Shunted 
  

  

  Telephone 
  to 
  the 
  Antenna 
  Current 
  as 
  used 
  in 
  the 
  reception 
  

   of 
  Wireless 
  Signals. 
  

  

  To 
  the 
  Editors 
  of 
  the 
  Philosophical 
  Magazine. 
  

   Gentlemen, 
  — 
  

  

  IN 
  your 
  January 
  number 
  you 
  published 
  a 
  paper 
  with 
  

   the 
  above 
  title 
  in 
  which 
  I 
  criticised 
  a 
  previous 
  

   communication 
  from 
  Mr. 
  van 
  der 
  Pol 
  ; 
  my 
  paper 
  was 
  

   followed 
  by 
  an 
  explanatory 
  note 
  in 
  which 
  Mr. 
  van 
  der 
  Pol 
  

   attempted 
  to 
  justify 
  his 
  methods 
  and 
  conclusions. 
  He 
  

   suggests 
  that 
  1 
  had 
  rather 
  lost 
  sight 
  of 
  the 
  motives 
  of 
  his 
  

   paper 
  and 
  of 
  certain 
  experimental 
  difficulties; 
  I 
  wish 
  to 
  

   show, 
  however, 
  that, 
  through 
  depending 
  too 
  much 
  on 
  

   Prof. 
  Love's 
  account 
  of 
  Austin's 
  work 
  and 
  apparently 
  

  

  * 
  Sir 
  Oliver 
  Lodge, 
  'Nature,' 
  March 
  21, 
  p. 
  44. 
  

  

  t 
  Or 
  \, 
  if 
  the 
  added 
  inertia 
  is 
  subject 
  to 
  gravitation. 
  

  

  