﻿Vibration 
  Curves 
  of 
  Violin 
  G 
  String 
  and 
  Belli/. 
  233 
  

   expressed 
  by 
  the 
  equation 
  

  

  " 
  e 
  

  

  where 
  m 
  is 
  the 
  mass 
  o£ 
  the 
  electron, 
  e 
  the 
  ionic 
  charge, 
  and 
  

   r 
  the 
  component, 
  in 
  the 
  direction 
  of 
  the 
  field, 
  o£ 
  the 
  velocity 
  

   with 
  which 
  the 
  electrons 
  are 
  projected 
  from 
  the 
  hot 
  surface. 
  

   If 
  this 
  equation 
  holds, 
  on 
  the 
  assumption 
  previously 
  stated, 
  

   we 
  may 
  deduce 
  from 
  the 
  curve 
  in 
  the 
  figure 
  that 
  the 
  velocity 
  

   with 
  which 
  electrons 
  are 
  projected 
  from 
  glowing 
  carbon 
  

   varies 
  from 
  1*5 
  x 
  10^ 
  centimetres 
  per 
  second 
  at 
  3375^ 
  

   absolute 
  to 
  2*5 
  X 
  10^ 
  centimetres 
  per 
  second 
  at 
  3690° 
  absolute. 
  

   In 
  a 
  similar 
  way, 
  from 
  the 
  result 
  previously 
  given, 
  a 
  lower 
  

   limit 
  to 
  the 
  velocity 
  with 
  which 
  electrons 
  are 
  projected 
  from 
  

   the 
  Nernst 
  filament 
  may 
  be 
  calculated 
  as 
  3 
  x 
  10' 
  centimetres 
  

   per 
  second. 
  

  

  The 
  Physical 
  Laboratory, 
  

   The 
  Universitv 
  of 
  Sydnev, 
  

  

  NoTember 
  28th, 
  1908." 
  - 
  -|--. 
  

  

  XXYIII. 
  Vihration 
  Curves 
  of 
  Violin. 
  G 
  String 
  and 
  Belly. 
  

   By 
  E. 
  H. 
  Baeton, 
  D.Sc, 
  F.R.S.E., 
  Prof, 
  of 
  Experimental 
  

   Physics, 
  and 
  T. 
  J. 
  Richmond, 
  B.Sc, 
  Research 
  Scholar^ 
  

   University 
  College, 
  Nottingham 
  *. 
  

  

  [Plates 
  IV.-VI.] 
  

  

  AT 
  the 
  end 
  of 
  1904 
  it 
  occurred 
  to 
  one 
  of 
  us 
  that 
  it 
  would 
  be 
  

   of 
  interest 
  to 
  trace 
  the 
  various 
  changes 
  in 
  vibration 
  form 
  

   experienced 
  as 
  the 
  motion 
  passes 
  from 
  a 
  vibrating 
  string 
  to 
  the 
  

   ear 
  by 
  means 
  of 
  the 
  bridge, 
  belly, 
  and 
  air 
  in 
  the 
  sound-box. 
  

   For 
  although 
  the 
  string 
  is 
  the 
  source 
  of 
  the 
  vibrations 
  

   concerned, 
  and 
  the 
  pitch 
  of 
  all 
  those 
  vibrations 
  depends 
  on 
  

   the 
  dimensions, 
  nature, 
  and 
  tension 
  of 
  the 
  string, 
  yet 
  it 
  is 
  

   only 
  after 
  the 
  occurrence 
  of 
  the 
  modifications 
  referred 
  to 
  

   that 
  the 
  ear 
  receives 
  the 
  impression 
  and 
  affords 
  the 
  hearer 
  

   any 
  evidence 
  of 
  the 
  quality 
  of 
  the 
  tone 
  produced 
  by 
  the 
  

   instrument 
  as 
  a 
  whole. 
  Hence, 
  although 
  both 
  by 
  theory 
  

   and 
  experiment 
  the 
  vibrations 
  of 
  a 
  string 
  have 
  been 
  investi- 
  

   gated 
  and 
  their 
  character 
  known, 
  whether 
  excited 
  by 
  plucking, 
  

   striking, 
  or 
  bowing, 
  there 
  still 
  remains 
  much 
  to 
  be 
  done 
  

   before 
  we 
  have 
  full 
  information 
  as 
  to 
  the 
  qualities 
  of 
  sound 
  

   actually 
  received 
  from 
  any 
  musical 
  instrument. 
  Or, 
  in 
  

   brief, 
  though 
  we 
  have 
  theoretically 
  a 
  sufficient 
  knowledge 
  of 
  

  

  * 
  Communicated 
  by 
  the 
  Authors. 
  

  

  