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  Proposed 
  International 
  Unit 
  of 
  Candle 
  Poioer. 
  

  

  o£ 
  all 
  the 
  comparisons, 
  the 
  following 
  relationships 
  are 
  

   established 
  between 
  the 
  above 
  units. 
  

  

  The 
  Pentane 
  unit 
  has 
  the 
  same 
  value 
  within 
  the 
  errors 
  of 
  

   experiment 
  as 
  the 
  bougie 
  decimale. 
  It 
  is 
  1*6 
  per 
  cent, 
  less 
  

   than 
  the 
  standard 
  candle 
  of 
  the 
  United 
  States 
  of 
  America, 
  

   and 
  11 
  per 
  cent, 
  greater 
  than 
  the 
  Hefner 
  unit. 
  

  

  In 
  order 
  to 
  come 
  into 
  agreement 
  with 
  Great 
  Britain 
  and 
  

   France, 
  the 
  Bureau 
  of 
  Standards 
  of 
  America 
  proposed 
  to 
  

   reduce 
  its 
  standard 
  candle 
  by 
  1*6 
  per 
  cent, 
  provided 
  that 
  

   France 
  and 
  Great 
  Britain 
  would 
  unite 
  with 
  America 
  in 
  

   maintaining 
  the 
  common 
  value 
  constant, 
  and 
  with 
  the 
  

   approval 
  of 
  other 
  countries 
  would 
  call 
  it 
  the 
  International 
  

   Candle. 
  The 
  National 
  Physical 
  Laboratory, 
  London, 
  and 
  

   the 
  Laboratoire 
  Central 
  d'Electricite, 
  Paris, 
  have 
  agreed 
  to 
  

   adopt 
  this 
  proposal 
  in 
  respect 
  to 
  the 
  photometric 
  standardiza- 
  

   tion 
  which 
  they 
  undertake, 
  and 
  the 
  date 
  agreed 
  upon 
  for 
  the 
  

   adoption 
  of 
  the 
  common 
  unit 
  and 
  the 
  change 
  of 
  unit 
  in 
  

   America 
  is 
  April 
  1, 
  1909. 
  

  

  The 
  following 
  simple 
  relations 
  will 
  therefore 
  hold 
  after 
  

   that 
  date 
  : 
  

  

  Proposed 
  New 
  Unit 
  = 
  1 
  Pentane 
  Candle. 
  

   = 
  1 
  Bougie 
  Decimale. 
  

   = 
  1 
  American 
  Candle. 
  

   = 
  1-11 
  Hefner 
  Unit. 
  

   = 
  O-lOl 
  Carcel 
  Unit. 
  

  

  Therefore 
  1 
  Hefner 
  Unit 
  = 
  0*90 
  of 
  the 
  proposed 
  unit. 
  

  

  The 
  Pentane 
  and 
  other 
  photometric 
  standards 
  in 
  use 
  in 
  

   America 
  will 
  hereafter 
  be 
  standardized 
  by 
  the 
  Bureau 
  of 
  

   Standards 
  in 
  terms 
  of 
  the 
  new 
  unit. 
  This, 
  within 
  the 
  limits 
  

   of 
  experimental 
  error, 
  will 
  bring 
  the 
  photometric 
  units 
  for 
  

   both 
  gas 
  and 
  electrical 
  industries 
  in 
  America 
  and 
  Great 
  

   Britain 
  and 
  for 
  the 
  electrical 
  industry 
  in 
  France 
  to 
  a 
  single 
  

   value, 
  and 
  the 
  Hefner 
  unit 
  will 
  be 
  in 
  the 
  simple 
  ratio 
  of 
  

   9/10 
  to 
  this 
  international 
  unit. 
  

  

  The 
  proposal 
  to 
  call 
  the 
  common 
  unit 
  of 
  light 
  to 
  be 
  main- 
  

   tained 
  jointly 
  by 
  the 
  national 
  standardizing 
  laboratories 
  of 
  

   America, 
  France, 
  and 
  Great 
  Britain, 
  the 
  " 
  International 
  

   Candle 
  " 
  has 
  been 
  submitted 
  to 
  the 
  International 
  El^K^tro- 
  

   technical 
  Commission, 
  and 
  through 
  it 
  to 
  all 
  the 
  countries 
  of 
  

   the 
  world 
  which 
  are 
  represented 
  on 
  that 
  Commission. 
  

  

  It 
  is 
  to 
  hoped 
  that 
  such 
  general 
  approval 
  will 
  be 
  secured, 
  

   and 
  that 
  in 
  the 
  near 
  future 
  the 
  term 
  " 
  International 
  Candle 
  '' 
  

   for 
  the 
  new 
  unit 
  will 
  have 
  official 
  international 
  sanction. 
  

  

  