﻿100 
  AXXTJAL 
  EEPOBT 
  SMITHSOXIAJS 
  IXSTTTUTIOX, 
  1929 
  

  

  system, 
  built 
  up 
  vrith 
  house 
  flies' 
  Tvings. 
  for 
  the 
  somewhat 
  larger 
  

   mica-Tane 
  instrmnent 
  employed 
  by 
  Doctor 
  Abbot 
  in 
  1923. 
  With 
  

   these 
  improvements 
  it 
  was 
  hoped 
  that 
  stars 
  of 
  the 
  fourth 
  or 
  even 
  

   fifth 
  magnitude 
  would 
  be 
  observable. 
  These 
  hopes 
  were 
  not 
  alto- 
  

   gether 
  realized. 
  The 
  sensitiveness 
  was 
  potentially 
  attained, 
  but. 
  

   unfortunately, 
  could 
  not 
  be 
  made 
  available 
  during 
  the 
  time 
  of 
  the 
  

   experiments 
  because 
  a 
  persistent 
  slight 
  charge 
  of 
  electricity 
  which 
  

   coidd 
  not 
  be 
  removed 
  created 
  a 
  governing 
  field, 
  which 
  reduced 
  the 
  

   time 
  of 
  single 
  swing 
  of 
  the 
  system 
  from 
  about 
  10 
  seconds 
  to 
  only 
  

   1.5 
  seconds 
  during 
  the 
  experiments. 
  On 
  this 
  account 
  the 
  deflections 
  

   in 
  the 
  stellar 
  spectra 
  were 
  regrettably 
  small. 
  Nevertheless, 
  with 
  the 
  

   special 
  observing 
  scale 
  which 
  had 
  been 
  devised, 
  very 
  satisfactory 
  

   results 
  were 
  reached, 
  and 
  in 
  one 
  case 
  on 
  a 
  star 
  of 
  only 
  3.S 
  magnitude. 
  

   These 
  observations 
  have 
  been 
  published 
  in 
  the 
  Astrophysical 
  Journal 
  

   for 
  May, 
  1929. 
  

  

  (h) 
  Aiontezunuz 
  station. 
  — 
  ^During 
  the 
  autumn 
  of 
  1923 
  the 
  appara- 
  

   tus 
  at 
  Montezuma 
  seemed 
  to 
  grow 
  insensitive, 
  so 
  that 
  a 
  critical 
  in- 
  

   spection 
  appeared 
  necessary. 
  By 
  the 
  generous 
  financial 
  assistance 
  of 
  

   Mr. 
  John 
  A. 
  Eoebling. 
  it 
  was 
  possible 
  to 
  send 
  Mr. 
  Aldrich 
  to 
  Chile. 
  

   This 
  expedition 
  occupied 
  him 
  from 
  January 
  to 
  March, 
  1929. 
  He 
  

   rebuilt 
  the 
  galvanometer 
  and 
  repaired 
  and 
  adjusted 
  other 
  instru- 
  

   ments 
  until 
  everything 
  was 
  in 
  satisfactory 
  condition. 
  Excellent 
  

   results 
  have 
  been 
  coming 
  in 
  regularly 
  of 
  the 
  Montezuma 
  observa- 
  

   tions 
  on 
  the 
  solar 
  constant 
  of 
  radiation. 
  These 
  are 
  published 
  daily 
  

   by 
  the 
  United 
  States 
  Weather 
  Bureau. 
  

  

  {c) 
  Table 
  Mountain 
  station. 
  — 
  ^The 
  unfortunate 
  trouble 
  with 
  the 
  

   pyranometer 
  at 
  Table 
  Mountain 
  has 
  already 
  been 
  described. 
  Not- 
  

   withstanding 
  this, 
  the 
  results 
  as 
  now 
  reduced 
  seem 
  satisfactory 
  and 
  

   are 
  very 
  nimieroas. 
  Indeed, 
  on 
  several 
  occasions 
  Table 
  Mountain 
  

   has 
  furnished 
  consecutive 
  daily 
  runs 
  of 
  solar-constant 
  determina- 
  

   tions 
  exceeding 
  50 
  days 
  and 
  once 
  exceeding 
  70 
  days. 
  

  

  The 
  Dobson 
  ozone 
  apparatus, 
  owned 
  by 
  the 
  Smithsonian 
  and 
  

   formerly 
  in 
  use 
  at 
  Montezuma, 
  was 
  returned 
  to 
  England 
  for 
  re- 
  

   adjustment 
  by 
  Doctor 
  Dobson. 
  It 
  was 
  reinstalled 
  at 
  Table 
  Mountain 
  

   in 
  the 
  autumn 
  of 
  192S 
  and 
  daily 
  determinations 
  of 
  atmospheric 
  ozone 
  

   have 
  been 
  made 
  with 
  it 
  whenever 
  possible 
  since 
  then. 
  These 
  measure- 
  

   ments 
  show 
  in 
  contrast 
  with 
  those 
  formerly 
  made 
  at 
  Montezuma 
  

   about 
  as 
  much 
  ozone 
  in 
  the 
  higher 
  atmosphere 
  above 
  California 
  as 
  

   has 
  been 
  found 
  in 
  Europe. 
  Also, 
  in 
  contrast 
  with 
  ^lontezuma 
  and 
  

   in 
  harmony 
  with 
  Europe, 
  they 
  show 
  a 
  decidedly 
  variable 
  quantity 
  of 
  

   ozone 
  from 
  day 
  to 
  day 
  and 
  from 
  month 
  to 
  month. 
  These 
  ozone 
  

   determinations 
  will 
  be 
  continued 
  at 
  Table 
  Motmtain 
  indefinitely. 
  

  

  {d) 
  Mount 
  BimkJcaroi. 
  — 
  The 
  National 
  Geographic 
  station 
  on 
  

   Mount 
  Brukkaros. 
  South 
  West 
  Africa, 
  which 
  cooperates 
  with 
  Mon- 
  

   tezuma 
  and 
  Table 
  Mountain 
  in 
  the 
  daily 
  observation 
  of 
  the 
  solar 
  

  

  