﻿1875.] 
  

  

  On 
  the 
  Lines 
  of 
  the 
  Solar 
  Spectrum. 
  

  

  201 
  

  

  Adopting 
  the 
  above 
  numbers 
  as 
  the 
  respective 
  numerical 
  values 
  of 
  each 
  

   order, 
  we 
  have 
  for 
  barracks 
  : 
  — 
  

  

  

  No. 
  of 
  

  

  

  Value 
  

  

  

  

  No. 
  of 
  order. 
  

  

  observations. 
  

  

  of 
  order. 
  

  

  

  Total. 
  

  

  o 
  

  

  89 
  

  

  X 
  

  

  2-13 
  

  

  

  189-57 
  

  

  3. 
  

  

  • 
  oo 
  

  

  X 
  

  

  3-46 
  

  

  

  304-48 
  

  

  4&5. 
  

  

  

  X 
  

  

  4-66 
  

  

  = 
  

  

  452-02 
  

  

  bums 
  . 
  . 
  

  

  .. 
  274 
  

  

  

  

  

  U4o 
  07 
  

  

  ; 
  a 
  mean 
  of 
  3*45. 
  

  

  

  

  

  

  

  hospitals 
  we 
  have 
  

  

  

  

  

  

  

  2. 
  

  

  20 
  

  

  X 
  

  

  2-13 
  

  

  

  42-60 
  

  

  3. 
  

  

  46 
  

  

  X 
  

  

  3-46 
  

  

  

  159-16 
  

  

  4 
  & 
  5 
  

  

  20 
  

  

  X 
  

  

  4-66 
  

  

  

  93-20 
  

  

  Sums. 
  . 
  

  

  .. 
  86 
  

  

  

  

  

  294-96 
  

  

  giving 
  a 
  mean 
  of 
  3*43. 
  

  

  Here 
  we 
  find 
  the 
  same 
  numerical 
  value 
  (signifying 
  close) 
  applied 
  to 
  

   0*580 
  in 
  hospitals 
  and 
  0-601 
  in 
  barracks. 
  There 
  is 
  thus, 
  even 
  in 
  this 
  

   comparatively 
  limited 
  number 
  of 
  observations, 
  a 
  confirmation 
  of 
  the 
  opi- 
  

   nion 
  that 
  more 
  air 
  is 
  necessary 
  to 
  keep 
  an 
  air-space 
  sweet 
  in 
  disease 
  than 
  

   in 
  health. 
  It 
  is, 
  however, 
  right 
  to 
  point 
  out 
  that 
  in 
  the 
  one 
  case 
  the 
  

   occupation 
  was 
  continuous, 
  and 
  in 
  the 
  other 
  chiefly 
  at 
  night 
  only. 
  

  

  II. 
  " 
  On 
  the 
  Atmospheric 
  Lines 
  of 
  the 
  Solar 
  Spectrum, 
  illustrated 
  

   by 
  a 
  Map 
  drawn 
  on 
  the 
  same 
  Scale 
  as 
  that 
  adopted 
  by 
  Kirch- 
  

   honV' 
  By 
  J. 
  B. 
  N. 
  Hennessey, 
  F.R.A.S. 
  Communicated 
  

   by 
  Prof. 
  Stokes, 
  Sec.R.S. 
  Received, 
  the 
  map 
  June 
  9, 
  1874, 
  

   the 
  text 
  January 
  11, 
  1875. 
  

  

  (Abstract.) 
  

  

  The 
  spectroscopic 
  observations 
  described 
  in 
  this 
  paper 
  were 
  made 
  with 
  

   instruments 
  belonging 
  to 
  the 
  Royal 
  Society, 
  and 
  in 
  accordance 
  with 
  

   certain 
  suggestions 
  which 
  had 
  been 
  made 
  to 
  the 
  author 
  by 
  a 
  committee 
  

   appointed 
  in 
  consequence 
  of 
  a 
  letter 
  of 
  his 
  to 
  Sir 
  Edward 
  Sabine, 
  

   President, 
  dated 
  13th 
  February, 
  1866. 
  In 
  view 
  of 
  his 
  residence 
  at 
  a 
  

   considerable 
  height 
  above 
  the 
  sea-level, 
  and 
  of 
  the 
  exceedingly 
  clear 
  

   atmosphere 
  prevailing 
  at 
  some 
  periods 
  of 
  the 
  year, 
  it 
  was 
  suggested 
  that 
  

   the 
  locality 
  was 
  peculiarly 
  favourable 
  for 
  a 
  determination 
  of 
  the 
  lines 
  of 
  

   the 
  solar 
  spectrum 
  due 
  to 
  atmospheric 
  absorption, 
  and 
  that, 
  for 
  this 
  pur- 
  

   pose, 
  the 
  solar 
  spectrum 
  when 
  the 
  sun 
  was 
  high 
  should 
  be 
  compared 
  with 
  

  

  r 
  2 
  

  

  