﻿G. 
  V. 
  Maclean 
  — 
  Velocity/ 
  of 
  Electric 
  Waves 
  in 
  Air. 
  15 
  

  

  This 
  latter 
  experiment 
  shows 
  that 
  the 
  wave-length 
  we 
  have 
  meas- 
  

   ured 
  was 
  that 
  of 
  the 
  fundamental 
  wave. 
  And, 
  moreover, 
  that 
  

   by 
  the 
  use 
  of 
  this 
  particular 
  coherer 
  or 
  the 
  electro 
  bolometer, 
  

   the 
  balancing 
  of 
  the 
  self-inductions 
  and 
  capacities 
  and 
  by 
  our 
  

   method 
  of 
  operating 
  the 
  oscillator, 
  all 
  the 
  electric 
  waves 
  in 
  the 
  

   number 
  of 
  different 
  waves 
  proceeding 
  from 
  the 
  E-uhmkorff 
  

   coil, 
  except 
  the 
  fundamental, 
  had 
  been 
  completely 
  damped. 
  If 
  

   such 
  had 
  not 
  been 
  the 
  case, 
  it 
  is 
  very 
  evident 
  the 
  measurement 
  

   so 
  taken 
  would 
  not 
  have 
  been 
  identical 
  with 
  those 
  first 
  observed. 
  

   The 
  experiment 
  was 
  pushed 
  further. 
  The 
  new 
  self-induc- 
  

   tion 
  (graphite) 
  of 
  the 
  coherer 
  circuit 
  being 
  retained, 
  the 
  

   <3apacity 
  of 
  the 
  oscillator 
  circuit 
  was 
  made 
  double 
  of 
  what 
  it 
  

   was 
  in 
  the 
  original 
  case 
  and, 
  therefore, 
  double 
  of 
  that 
  now 
  in 
  

   the 
  coherer 
  circuit. 
  At 
  those 
  points 
  where 
  the 
  original 
  read- 
  

   ings 
  indicated 
  nodes 
  and 
  an 
  ti- 
  nodes 
  the 
  readings 
  were 
  now 
  

   <jhanged. 
  The 
  following 
  table 
  shows 
  some 
  of 
  the 
  changes- 
  

  

  The 
  new 
  self-induction 
  in 
  the 
  

   The 
  new 
  self-induction 
  in 
  the 
  coherer 
  circuit 
  coherer 
  circuit 
  and 
  the 
  capacity 
  

   and 
  the 
  oritrinal 
  capacity 
  in 
  the 
  in 
  the 
  oscillator 
  circuit, 
  

  

  oscillator 
  circuit. 
  doubled. 
  

  

  istance 
  in 
  nis. 
  of 
  the 
  

  

  coherer 
  from 
  the 
  

  

  reflector. 
  

  

  Difl'erence 
  between 
  the 
  

  

  maxuiium 
  and 
  increased 
  

  

  maximum 
  readings 
  

  

  of 
  the 
  m-a-m. 
  

  

  Difl'erence 
  hetVeen 
  the 
  

  

  maximum 
  and 
  increased 
  

  

  maximum 
  readini^s 
  

  

  of 
  the 
  m-a-m. 
  

  

  1-1500 
  

  

  

  0-000 
  

  

  0075 
  

  

  2-6288 
  

  

  

  260 
  

  

  0-275 
  

  

  4-1075 
  

  

  

  0-000 
  

  

  0-150 
  

  

  5-5863 
  

  

  

  0-262 
  

  

  250 
  

  

  70650 
  

  

  

  0000 
  

  

  081 
  

  

  

  

  (average 
  of 
  5 
  

   readings) 
  

  

  (average 
  of 
  5 
  

   readings) 
  

  

  Similar 
  changes 
  took 
  place 
  at 
  other 
  points. 
  

  

  Next 
  the 
  capacity 
  of 
  the 
  coherer 
  circuit 
  was 
  altered 
  and 
  as 
  a 
  

   consequence, 
  at 
  those 
  points 
  where 
  the 
  original 
  readings 
  were 
  

   taken, 
  the 
  readings 
  now 
  were 
  different. 
  Finally 
  the 
  capacity 
  

   (i. 
  e. 
  the 
  tinfoil 
  plates) 
  of 
  the 
  coherer 
  circuit 
  was 
  left 
  out 
  

   entirely 
  and 
  so 
  also 
  was 
  the 
  self-induction, 
  for 
  at 
  this 
  stage 
  of 
  

   the 
  experiment 
  the 
  graphite 
  broke. 
  The 
  readings 
  were 
  now 
  

   of 
  all 
  sorts, 
  the 
  needle 
  moving 
  very 
  capriciously, 
  whenever 
  the 
  

   sparking 
  began 
  or 
  continued 
  at 
  the 
  oscillator. 
  No 
  regular 
  

   increase 
  and 
  decrease 
  in 
  the 
  readings 
  could 
  be 
  determined, 
  as 
  

   the 
  coherer 
  was 
  moved 
  farther 
  and 
  farther 
  from 
  the 
  reflector. 
  

   At 
  one 
  time 
  the 
  needle 
  would 
  be 
  deflected 
  four 
  or 
  five 
  whole 
  

   divisions 
  of 
  the 
  Mille- 
  Ampere 
  meter 
  scale 
  while 
  in 
  the 
  next 
  

   second, 
  at 
  the 
  same 
  place, 
  there 
  would 
  be 
  only 
  a 
  displacement 
  

   of 
  the 
  needle 
  of 
  '2 
  or 
  -3 
  of 
  a 
  division 
  in 
  the 
  forward 
  direction 
  

   or 
  else 
  a 
  deflection 
  in 
  the 
  opposite 
  direction, 
  and 
  even 
  at 
  times 
  

   the 
  needle 
  trembled 
  as 
  if 
  acted 
  upon 
  by 
  almost 
  equally 
  oppos- 
  

   ing 
  influences. 
  These 
  irregular 
  motions 
  of 
  the 
  needle 
  made 
  a 
  

   great 
  contrast 
  with 
  the 
  regular 
  motions 
  when 
  the 
  coherer 
  and 
  

  

  