﻿178 
  

  

  Mr. 
  Prentice 
  Reeves 
  on 
  the 
  

  

  mean 
  curve 
  as 
  compared 
  with 
  the 
  curves 
  of 
  other 
  writers. 
  

   In 
  Table 
  II. 
  are 
  shown 
  the 
  results 
  obtained 
  by 
  using 
  the 
  

   different 
  values 
  for 
  the 
  acetylene 
  emission 
  and 
  the 
  mean 
  

  

  .4$ 
  .JO 
  .# 
  .61.53 
  .5*. 
  65. 
  56 
  .57 
  *S8 
  .59 
  .60 
  .61 
  .62 
  .63 
  M 
  

  

  Aufaarjz 
  mean 
  of 
  S3 
  subjects. 
  

  

  -«•- 
  -. 
  Nuf 
  finds 
  " 
  »» 
  21 
  »• 
  

  

  i/veJ- 
  » 
  "A? 
  •.'» 
  . 
  

  

  — 
  — 
  Curve 
  calculated 
  ffQm 
  formula 
  (by 
  

   Nutting). 
  

  

  from 
  Nutting's 
  and 
  Ives's 
  results, 
  as 
  well 
  as 
  the 
  results 
  com- 
  

   puted 
  from 
  the 
  formula 
  offered 
  by 
  Nutting. 
  This 
  formula 
  

   was 
  found 
  to 
  represent 
  visibility 
  very 
  closely 
  between 
  the 
  

   wave-lengths 
  of 
  *48 
  and 
  '67 
  and 
  is 
  of 
  the 
  form 
  

  

  V 
  = 
  VmRV 
  (1 
  " 
  R) 
  

  

  where 
  R 
  = 
  \ 
  max./A, 
  and 
  a=181. 
  When 
  the 
  writer 
  used 
  

   Coblentz's 
  revised 
  data 
  for 
  acetylene 
  the 
  results 
  agreed 
  re- 
  

   markably 
  well 
  with 
  these 
  computed 
  results. 
  

  

  In 
  Table 
  III. 
  the 
  acetylene 
  values 
  used 
  by 
  the 
  writer 
  and 
  

  

  