﻿Mean 
  Annual 
  Temperature 
  Variation. 
  

  

  407 
  

  

  ting 
  this 
  estimate 
  and 
  supposing 
  that 
  a 
  curve 
  of 
  67° 
  (=50 
  + 
  17) 
  

   amplitude 
  would 
  represent 
  the 
  variation 
  corresponding 
  to 
  the 
  

   coefficient 
  of 
  perfect 
  atmospheric 
  transparency* 
  at 
  the 
  latitude 
  

   of 
  Nertchinsk, 
  the 
  lowest 
  temperature 
  of 
  January 
  must 
  be 
  con- 
  

   sidered 
  6*5° 
  too 
  high 
  and 
  the 
  highest 
  July 
  temperature 
  11'5° 
  

   too 
  low, 
  since 
  the 
  extreme 
  dailv 
  mean 
  temperatures 
  should 
  be 
  

   - 
  37° 
  and 
  + 
  30°. 
  

  

  Fig. 
  4. 
  

  

  o 
  

   7C 
  

  

  16 
  

  

  15 
  

  

  14 
  

  

  13 
  

  

  12 
  

  

  

  

  

  

  

  \ 
  

   \ 
  

  

  A 
  / 
  / 
  

  

  

  

  

  

  \ 
  

   \ 
  

   \ 
  

  

  / 
  /^ 
  

   / 
  / 
  

   / 
  / 
  

  

  

  

  

  

  

  / 
  / 
  

   / 
  / 
  

   / 
  / 
  

   / 
  / 
  

   / 
  1 
  

  

  

  \ 
  

  

  

  

  

  i 
  

  

  1 
  

   I 
  

   I 
  

  

  

  

  1 
  1 
  

   10 
  

  

  9 
  

   8 
  

   7 
  

   6 
  

   5 
  

   4 
  

   3 
  

  

  

  ■ 
  

  

  i 
  

   i 
  

  

  / 
  A 
  

  

  1 
  s 
  

  

  i 
  

  

  

  

  

  y 
  

  

  IS* 
  1 
  

  

  hi 
  ' 
  

  

  1 
  / 
  

   / 
  

  

  i 
  

  

  

  

  

  

  7 
  

  

  i 
  

  

  

  

  

  

  

  

  

  

  

  

  

  / 
  

  

  i 
  

  

  i 
  

  

  

  

  

  

  

  Thus 
  it 
  may 
  be 
  that, 
  in 
  this 
  case, 
  the 
  decrease 
  in 
  amplitude 
  

   is 
  in 
  close 
  connection 
  with 
  the 
  annual 
  variation 
  of 
  atmospheric 
  

   moisture. 
  During 
  the 
  summer 
  months, 
  the 
  greater 
  amount 
  of 
  

   aqueous 
  vapor 
  diminishes 
  the 
  coefficient 
  of 
  atmospheric 
  

   (thermal) 
  transparency 
  very 
  much 
  more 
  than 
  during 
  the 
  winter 
  

   months, 
  and 
  so 
  it 
  is 
  evident 
  that 
  the 
  summer 
  temperatures 
  

   differ 
  more 
  x 
  from 
  what 
  they 
  should 
  be 
  than 
  the 
  temperatures 
  

   observed 
  during 
  the 
  winter. 
  

  

  This 
  leads 
  to 
  the 
  question 
  whether 
  the 
  steps 
  of 
  the 
  Nertchinsk 
  

   temperature 
  curve, 
  and 
  perhaps 
  also 
  the 
  steps 
  of 
  the 
  curves 
  of 
  

   several 
  other 
  stations, 
  are 
  not 
  partially 
  due 
  to 
  a 
  rhythmical 
  

   transport 
  of 
  atmospheric 
  moisture. 
  

  

  * 
  A. 
  Angot, 
  Ann. 
  Bur. 
  Centr. 
  Met. 
  France, 
  1883, 
  i, 
  p. 
  B. 
  121. 
  

  

  Am. 
  Jour. 
  Sci.— 
  Fourth 
  Series, 
  Vol. 
  XLIII, 
  No. 
  257.— 
  May, 
  1917. 
  

  

  28 
  

  

  