﻿016 
  Mr. 
  J. 
  J. 
  Taudin 
  Ohabot 
  on 
  Rotating 
  

  

  in 
  assuming 
  that 
  the 
  distribution 
  of 
  velocity 
  determined 
  by 
  

   the 
  experiments 
  is 
  the 
  same 
  as 
  that 
  which 
  would 
  hold 
  in 
  

   the 
  steady 
  state. 
  Strictly 
  speaking, 
  this 
  conclusion 
  is 
  true; 
  

   but 
  when 
  the 
  matter 
  is 
  looked 
  at 
  quantitively 
  it 
  will 
  be 
  

   seen 
  thai 
  for 
  all 
  practical 
  purposes 
  it 
  is 
  false. 
  The 
  number 
  

   of 
  electrons 
  which 
  strike 
  the 
  bounding 
  surface 
  from 
  the 
  

   inside 
  is 
  enormous 
  compared 
  with 
  the 
  number 
  which 
  escape, 
  

   and 
  the 
  number 
  which 
  escape 
  must 
  be 
  approximately 
  the 
  

   same, 
  whether 
  the 
  state 
  is 
  steady 
  or 
  otherwise, 
  since 
  the 
  

   electric 
  fields 
  are 
  too 
  small 
  to 
  be 
  appreciable 
  within 
  the 
  sur- 
  

   face 
  layer. 
  It 
  fellows 
  that, 
  even 
  in 
  the 
  steady 
  state, 
  but 
  

   an 
  insignificant 
  proportion 
  of 
  tin 
  1 
  electrons 
  which 
  escape 
  

   from 
  the 
  metal 
  will 
  be 
  made 
  up 
  of 
  those 
  returned 
  to 
  it 
  and 
  

   which 
  do 
  not 
  undergo 
  a 
  considerable 
  number 
  of 
  encounters 
  

   within 
  the 
  metal. 
  The 
  number, 
  and 
  distribution 
  of 
  velocity, 
  

   of 
  the 
  electrons 
  emitted 
  by 
  the 
  metal 
  must 
  therefore 
  be 
  

   the 
  same, 
  for 
  all 
  practical 
  purposes, 
  under 
  the 
  conditions 
  

   of 
  these 
  experiments 
  as 
  in 
  the 
  steady 
  state. 
  We 
  may 
  

   therefore 
  claim 
  to 
  have 
  proved 
  by 
  direct 
  experiment 
  the 
  

   truth 
  of 
  .Maxwell'- 
  classical 
  theorems 
  relating 
  to 
  the 
  dis- 
  

   tribution 
  of 
  velocity 
  among 
  a 
  collection 
  of 
  material 
  particles 
  

   in 
  statistical 
  equilibrium. 
  

  

  Several 
  of 
  the 
  preceding 
  statements 
  are 
  true 
  only 
  within 
  

   the 
  limitation 
  imposed 
  by 
  u 
  considerable 
  experimental 
  error. 
  

   There 
  appears 
  to 
  be 
  no 
  obvious 
  reason 
  why 
  the 
  limit 
  of 
  error 
  

   should 
  not 
  be 
  materially 
  reduced. 
  Experiments 
  with 
  this 
  

   object 
  and 
  in 
  other 
  directions 
  suggested 
  by 
  the 
  results 
  of 
  

   these 
  researches 
  are 
  being 
  instituted. 
  

  

  Princeton, 
  N. 
  J., 
  

   July 
  6, 
  1908. 
  

  

  LXXVI1. 
  Rotating 
  EarthAnduclor 
  without 
  Sliding 
  Contacts. 
  

   By 
  J. 
  J. 
  Taudin 
  Chabot*. 
  _ 
  

  

  [Plate 
  XXVII.] 
  

  

  AS 
  shown 
  in 
  a 
  former 
  article! 
  it 
  is 
  possible 
  — 
  in. 
  spite 
  of 
  

   all 
  constructions 
  which 
  previously 
  apparently 
  demon- 
  

   strated 
  the 
  contrary 
  — 
  to 
  connect 
  together 
  the 
  stationary 
  part 
  

   of 
  a 
  circuit 
  and 
  the 
  rotating 
  coil 
  (the 
  rotation 
  being 
  con- 
  

   tinuously 
  in 
  one 
  direction) 
  by 
  means 
  of 
  an 
  unbroken 
  con- 
  

   ducting 
  connexion 
  — 
  i. 
  e. 
  without 
  any 
  sliding 
  contacts. 
  

  

  I 
  have 
  recently 
  had 
  an 
  earth-inductor 
  made 
  according 
  to 
  

   the 
  principle 
  then 
  explained, 
  but 
  which 
  as 
  constructed 
  has 
  

  

  * 
  Communicated 
  by 
  the 
  Author. 
  

   t 
  Phil. 
  Ma?. 
  October 
  1902. 
  

  

  