﻿128 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  VARIATION 
  OF 
  ANTIRACHITIC 
  EFFICIENCY 
  

   WITH 
  TIME 
  OF 
  DAY 
  

  

  ZSmm 
  OZONE. 
  

   JS'N.LAT. 
  

  

  JUNE 
  22 
  

  

  -dUNE 
  I 
  AND 
  JULY 
  10 
  

   MAY 
  I 
  AND 
  AUG 
  12 
  

   -APR 
  15 
  AND 
  AUG 
  29 
  

   APR 
  I 
  AND 
  SEPT 
  12 
  

   MAR 
  15 
  AND 
  SEPT 
  27 
  

   MAR 
  I 
  AND 
  OCT 
  12 
  

   FEB 
  15 
  AND 
  OCT 
  28 
  

   FEB 
  I 
  AND 
  NOV. 
  II 
  

   AN 
  I 
  AND 
  DEC 
  12 
  

  

  TIME 
  OF 
  DAY 
  

  

  Figure 
  18. 
  — 
  Hourly 
  variation 
  of 
  solar 
  antirachitic 
  effect. 
  (2.8 
  mm. 
  zenith 
  ozone, 
  

  

  38° 
  N. 
  latitude.) 
  

  

  70 
  

   = 
  60 
  

  

  50 
  

  

  540 
  

  

  VARIATION 
  OF 
  ANTIRACHITIC 
  EFFICIE.NCY 
  WITH 
  

   TIME 
  OF 
  DAY 
  

  

  2 
  8mm 
  OZONE 
  

   43'NLAT 
  

  

  -dUNE 
  I 
  AND 
  JULY 
  IO 
  

   MAY 
  I 
  AND 
  AUG 
  \2 
  

  

  APR 
  15 
  AND 
  AUG 
  29 
  

  

  APR 
  I 
  AND 
  SEPT 
  12 
  

   MAR 
  15 
  AND 
  SEPT 
  27 
  

   MAR 
  I 
  AND 
  OCT 
  12 
  

   FEE. 
  15 
  AMD 
  OCT 
  28 
  

  

  .FEB. 
  I 
  AND 
  NOV 
  II 
  

   JAN. 
  I 
  AND 
  DEC 
  12 
  

  

  10 
  II 
  12 
  I 
  

  

  TIMEOF 
  DAY 
  

  

  Figure 
  19. 
  — 
  Hourly 
  variation 
  of 
  solar 
  antirachitic 
  effect 
  (2.8 
  mm. 
  zenith 
  ozone, 
  

  

  43° 
  N. 
  latitude.) 
  

  

  