﻿APPENDIX 
  8 
  

  

  REPORT 
  ON 
  THE 
  ASTROPHYSICAL 
  OBSERVATORY 
  

  

  Sir 
  : 
  I 
  have 
  the 
  honor 
  to 
  submit 
  the 
  following 
  report 
  on 
  the 
  activ- 
  

   ities 
  of 
  the 
  Astrophysical 
  Observatory, 
  including 
  the 
  Division 
  of 
  

   Astrophysical 
  Research 
  and 
  the 
  Division 
  of 
  Radiation 
  and 
  Organisms, 
  

   for 
  the 
  fiscal 
  year 
  ended 
  June 
  30, 
  1943 
  : 
  

  

  DIVISION 
  OF 
  ASTROPHYSICAL 
  RESEARCH 
  

  

  The 
  study 
  of 
  the 
  solar-constant 
  values 
  published 
  in 
  March 
  1942 
  

   as 
  table 
  24, 
  volume 
  6 
  of 
  the 
  Annals 
  of 
  the 
  Observatory, 
  confirmed 
  the 
  

   discovery 
  that 
  the 
  variation 
  of 
  the 
  sun's 
  output, 
  seemingly 
  irregular, 
  

   is 
  really 
  made 
  up 
  of 
  numerous 
  regular 
  periodicities, 
  all 
  being 
  closely 
  

   aliquot 
  parts 
  of 
  273 
  months. 
  By 
  combining 
  their 
  influences 
  a 
  pre- 
  

   diction 
  was 
  made 
  of 
  the 
  march 
  of 
  solar 
  variation 
  from 
  1939 
  through 
  

   the 
  year 
  1945. 
  This 
  appears 
  in 
  figure 
  14 
  of 
  volume 
  6 
  of 
  the 
  Annals. 
  

  

  In 
  this 
  way 
  it 
  was 
  shown 
  that 
  the 
  years 
  1940 
  to 
  1947 
  would 
  probably 
  

   be 
  the 
  most 
  interesting 
  and 
  important 
  years 
  to 
  study 
  the 
  sun's 
  varia- 
  

   tion 
  since 
  the 
  early 
  twenties. 
  As 
  the 
  Smithsonian 
  Astrophysical 
  

   Observatory 
  is 
  the 
  only 
  agency 
  in 
  the 
  world 
  which 
  follows 
  the 
  varia- 
  

   tion 
  of 
  the 
  sun's 
  output 
  of 
  radiation, 
  it 
  therefore 
  seemed 
  of 
  extreme 
  

   importance 
  to 
  keep 
  the 
  record 
  unbroken 
  through 
  these 
  critical 
  years. 
  

   Hence, 
  despite 
  demands 
  of 
  the 
  war 
  manpower 
  situation, 
  every 
  avail- 
  

   able 
  means 
  has 
  been 
  used 
  to 
  keep 
  the 
  three 
  field 
  observatories 
  at 
  Mon- 
  

   tezuma, 
  Chile, 
  Table 
  Mountain, 
  Calif., 
  and 
  Tyrone, 
  N. 
  Mex., 
  in 
  opera- 
  

   tion. 
  Thus 
  far 
  these 
  efforts 
  have 
  been 
  successful, 
  notwithstanding 
  

   the 
  loss 
  of 
  three 
  experienced 
  observers 
  from 
  a 
  total 
  field 
  staff 
  of 
  six. 
  

  

  Considerable 
  progress 
  has 
  been 
  made 
  at 
  Washington 
  in 
  the 
  study 
  

   of 
  short-interval 
  changes 
  of 
  the 
  solar 
  radiation 
  in 
  their 
  relation 
  to 
  

   weather. 
  As 
  first 
  shown 
  in 
  Smithsonian 
  publications 
  Nos. 
  3392 
  and 
  

   3397 
  in 
  the 
  year 
  1936, 
  the 
  sun's 
  short-interval 
  variations, 
  though 
  aver- 
  

   aging 
  only 
  0.7 
  percent, 
  are 
  important 
  elements, 
  even 
  governing 
  ele- 
  

   ments, 
  in 
  weather. 
  The 
  weather 
  effects 
  of 
  individual 
  solar 
  changes 
  

   are 
  found 
  to 
  last 
  at 
  least 
  2 
  weeks. 
  These 
  studies 
  of 
  the 
  year 
  1936 
  have 
  

   been 
  repeated 
  this 
  year 
  employing 
  the 
  improved 
  and 
  enlarged 
  "solar 
  

   constant" 
  data 
  published 
  as 
  table 
  24, 
  volume 
  6 
  of 
  our 
  Annals. 
  The 
  

   new 
  results 
  are 
  even 
  more 
  convincing 
  than 
  the 
  provisional 
  ones 
  just 
  

   referred 
  to. 
  They 
  have 
  been 
  extended 
  to 
  deal 
  with 
  the 
  weather 
  of 
  

   several 
  cities 
  in 
  different 
  parts 
  of 
  the 
  world, 
  for 
  both 
  temperature 
  

   and 
  barometric 
  pressure. 
  It 
  is 
  expected 
  to 
  publish 
  soon 
  on 
  this 
  

   subject. 
  

  

  At 
  Washington 
  two 
  computers 
  have 
  continued 
  reductions 
  of 
  solar- 
  

   constant 
  observations, 
  but 
  have 
  not, 
  of 
  course, 
  been 
  able 
  to 
  keep 
  up 
  

   to 
  date 
  with 
  the 
  results, 
  inasmuch 
  as 
  these 
  computers 
  were 
  also 
  called 
  

  

  