﻿1875.] 
  

  

  New 
  Map 
  of 
  the 
  Solar 
  Spectrum. 
  

  

  153 
  

  

  Region 
  of 
  spectrum, 
  3900-4100. 
  

  

  Number 
  of 
  lines 
  in 
  Angstrom's 
  " 
  Spectre 
  Normal 
  " 
  39 
  

  

  „ 
  ,, 
  Angstrom's 
  and 
  Thalen's 
  map 
  of 
  the 
  

  

  violet 
  part 
  of 
  the 
  solar 
  spectrum 
  .... 
  185 
  

  

  „ 
  „ 
  Cornu's 
  map 
  205 
  

  

  „ 
  „ 
  new 
  map 
  518 
  

  

  It 
  will 
  serve 
  further 
  to 
  illustrate 
  the 
  advantages 
  of 
  the 
  photographic 
  

   method, 
  to 
  compare 
  the 
  number 
  of 
  lines 
  in 
  the 
  spectra 
  of 
  metals 
  already 
  

   observed 
  with 
  the 
  number 
  of 
  lines 
  of 
  the 
  same 
  metal 
  given 
  by 
  Angstrom 
  

   in 
  the 
  " 
  Spectre 
  Normal." 
  

  

  Eegion 
  of 
  spectrum, 
  3900-4100. 
  

  

  Metal. 
  

   Ee 
  

  

  Lines 
  in 
  new 
  

  

  71 
  

  

  map. 
  Lines 
  in 
  ThaleVs 
  map. 
  

   19 
  

  

  Mn 
  

  

  53 
  

  

  12 
  

  

  Co 
  

  

  47 
  

  

  

  m 
  

  

  A 
  17 
  

  

  

  Ce 
  

  

  163 
  

  

  

  U 
  

  

  18 
  

  

  

  Cr 
  

  

  24 
  

  

  

  Ba 
  

  

  7 
  

  

  

  Sr 
  

  

  

  

  Ca 
  

  

  7 
  

  

  6 
  

  

  K 
  

  

  2 
  

  

  

  Al 
  

  

  2 
  

  

  2 
  

  

  

  Total 
  416 
  

  

  Total.... 
  39 
  

  

  The 
  purification 
  of 
  the 
  various 
  metallic 
  spectra 
  has 
  at 
  present 
  been 
  

   only 
  partially 
  effected 
  ; 
  but 
  I 
  have 
  seen 
  enough 
  already 
  to 
  convince 
  me 
  

   of 
  the 
  extreme 
  rigour 
  with 
  which 
  the 
  principle 
  I 
  have 
  already 
  announced 
  

   may 
  be 
  applied, 
  while, 
  at 
  the 
  same 
  time, 
  there 
  are 
  evidences 
  that 
  the 
  

   application 
  of 
  it 
  may 
  lead 
  to 
  some 
  results 
  not 
  anticipated 
  in 
  the 
  first 
  

   instance. 
  

  

  My 
  object 
  in 
  laying 
  these 
  maps 
  before 
  the 
  Society, 
  and 
  presenting 
  this 
  

   ad 
  interim 
  report 
  of 
  progress, 
  is 
  to 
  appeal 
  to 
  some 
  other 
  man 
  of 
  science, 
  

   if 
  not 
  in 
  England, 
  then 
  in 
  some 
  other 
  country, 
  to 
  come 
  forward 
  to 
  aid 
  in 
  

   the 
  work, 
  which 
  it 
  is 
  improbable 
  that 
  I, 
  with 
  my 
  small 
  observational 
  

   means 
  and 
  limited 
  time, 
  can 
  carry 
  to 
  a 
  termination. 
  I 
  reckon 
  that, 
  

   having 
  regard 
  to 
  routine 
  solar 
  work, 
  it 
  will 
  require 
  another 
  year 
  before 
  

   the 
  portion 
  from 
  H 
  to 
  Gr 
  is 
  completely 
  finished, 
  even 
  for 
  the 
  metals 
  the 
  

   spectra 
  of 
  which 
  are 
  shown 
  in 
  the 
  maps 
  now 
  exhibited. 
  When 
  this 
  is 
  

   done 
  there 
  will 
  still 
  remain 
  outstanding 
  all 
  the 
  ultra-violet 
  portion, 
  the 
  

   portion 
  from 
  Gr 
  to 
  E 
  (both 
  capable 
  of 
  being 
  photographed 
  by 
  short 
  expo- 
  

   sure), 
  and 
  the 
  whole 
  of 
  the 
  less-refrangible 
  part 
  (which 
  both 
  Draper 
  and 
  

  

  o 
  2 
  

  

  