﻿Distribution 
  of 
  Energy 
  in 
  the 
  Spectra 
  of 
  Gases. 
  817 
  

  

  (1) 
  Outside 
  effects, 
  whose 
  magnitude 
  and 
  direction 
  might 
  

  

  vary. 
  These 
  would 
  vitiate 
  the 
  smaller 
  readings 
  to 
  a 
  

   greater 
  extent 
  than 
  the 
  larger. 
  A 
  time 
  must 
  be 
  chosen 
  

   when 
  the 
  system 
  appears 
  as 
  quiescent 
  as 
  possible, 
  and 
  

   in 
  the 
  present 
  case 
  this 
  has 
  precluded 
  the 
  possibility 
  o£ 
  

   reiving 
  on 
  any 
  readings 
  obtained 
  either 
  after 
  8 
  o'clock 
  

   in 
  the 
  morning 
  or 
  before 
  6 
  o'clock 
  in 
  the 
  evening. 
  At 
  

   the 
  best 
  of 
  times 
  the 
  system 
  would 
  ;; 
  wobble 
  " 
  over 
  not 
  

   more 
  than 
  about 
  0'3 
  mm., 
  although 
  there 
  might 
  be 
  

   a 
  slow 
  creep 
  of 
  the 
  zero 
  which 
  would 
  not 
  affect 
  the 
  

   readings 
  to 
  any 
  degree. 
  

  

  (2) 
  An 
  effect 
  dne 
  to 
  the 
  magnetic 
  field 
  of 
  the 
  transformer 
  

  

  was 
  noticed, 
  but 
  it 
  was 
  not 
  very 
  great. 
  In 
  order 
  to 
  

   obviate 
  it 
  the 
  transformer 
  was 
  moved 
  into 
  the 
  next 
  

   room 
  so 
  as 
  to 
  be 
  at 
  least 
  25 
  feet 
  away 
  from 
  the 
  galva- 
  

   nometer. 
  

  

  (3) 
  An 
  effect 
  due 
  to 
  the 
  proximity 
  of 
  the 
  discharge-tube 
  to 
  

  

  the 
  slit 
  of 
  the 
  spectrometer. 
  This 
  was 
  partly 
  of 
  the 
  

   nature 
  of 
  an 
  electrostatic 
  induction, 
  for 
  it 
  was 
  lessened 
  

   on 
  earthing 
  the 
  spectroscope. 
  Both 
  this 
  and 
  the 
  pre- 
  

   vious 
  cause 
  of 
  disturbance 
  affect 
  the 
  smaller 
  readings 
  

   to 
  a 
  greater 
  extent 
  than 
  the 
  larger. 
  

  

  (4) 
  The 
  rapid 
  electric 
  oscillations 
  seem 
  to 
  have 
  an 
  effect 
  on 
  

  

  the 
  control-magnet 
  of 
  the 
  galvanometer, 
  for 
  even 
  when 
  

   there 
  was 
  a 
  space 
  of 
  some 
  'Z0 
  feet 
  between 
  the 
  oscilla- 
  

   tory 
  circuit 
  and 
  the 
  galvanometer 
  there 
  was 
  a 
  small 
  

   residual 
  disturbance. 
  For 
  some 
  unexplained 
  reason 
  it 
  

   was 
  very 
  much 
  greater 
  when 
  the 
  spark-gap 
  was 
  

   immersed 
  in 
  oil. 
  

  

  (5) 
  The 
  most 
  influential 
  source 
  of 
  inaccuracy, 
  especially 
  

  

  when 
  large 
  currents 
  were 
  used, 
  was 
  the 
  variation 
  ot 
  

   the 
  strength 
  and 
  conditions 
  of 
  the 
  discharge 
  itself. 
  

   From 
  the 
  electrometer 
  curve 
  (no. 
  1 
  A) 
  and 
  from 
  the 
  

   radiation 
  curve 
  (no. 
  5), 
  it 
  is 
  clear 
  that 
  with 
  uncon- 
  

   densed 
  discharges 
  the 
  current 
  does 
  remain 
  fairly 
  

   constaut, 
  but 
  the 
  great 
  heating 
  in 
  the 
  case 
  of 
  the 
  dis- 
  

   ruptive 
  currents 
  makes 
  this 
  sort 
  of 
  error 
  by 
  far 
  the 
  

   most 
  formidable. 
  There 
  is 
  this 
  advantage, 
  that 
  the 
  

   errors 
  so 
  occasioned 
  will 
  affect 
  all 
  readings 
  in 
  the 
  same 
  

   proportion. 
  

  

  The 
  conditions 
  which 
  make 
  for 
  constancy 
  in 
  the 
  readings 
  

   have 
  been 
  carefully 
  investigated. 
  

  

  AVhen 
  the 
  galvanometer-circuit 
  is 
  closed 
  the 
  deflexions 
  are 
  

   larger 
  than 
  when 
  it 
  is 
  open, 
  and 
  appear 
  to 
  have 
  a 
  tendency 
  

   to 
  be 
  negative 
  in 
  sign. 
  When 
  the 
  radiation 
  is 
  being 
  

  

  PMl. 
  Mag. 
  S. 
  6. 
  Vol. 
  26. 
  No. 
  155. 
  For. 
  1913. 
  3 
  K 
  

  

  