﻿402 
  H. 
  ArctowsJci 
  — 
  Normal 
  Anomalies 
  of 
  the 
  

  

  Art. 
  XXXYIII. 
  — 
  Normal 
  Anomalies 
  of 
  the 
  Mean 
  Annual 
  

   Temperature 
  Variation 
  / 
  by 
  Henryk 
  Arctowski. 
  

  

  The 
  curves 
  representing 
  annual 
  variations 
  of 
  atmospheric 
  

   temperature 
  are 
  generally 
  derived 
  from 
  monthly 
  means. 
  For 
  

   many 
  stations, 
  belonging 
  to 
  different 
  climates, 
  these 
  curves 
  

   convey 
  the 
  impression 
  of 
  representing 
  a 
  cyclic 
  variation, 
  reflect- 
  

   ing, 
  with 
  different 
  amplitudes 
  and 
  more 
  or 
  less 
  retardation, 
  the 
  

   seasonal 
  changes 
  of 
  solar 
  declination. 
  

  

  If, 
  in 
  the 
  case 
  of 
  long 
  series 
  of 
  observations, 
  instead 
  of 
  

   monthly 
  means, 
  the 
  averages 
  for 
  each 
  day 
  of 
  the 
  year 
  are 
  taken 
  

   into 
  consideration, 
  the 
  diagrams 
  thus 
  obtained 
  display 
  most 
  

   remarkable 
  anomalies. 
  As 
  typical 
  examples 
  I 
  would 
  refer 
  to 
  

   the 
  curves 
  of 
  Koenigsberg, 
  Munich, 
  Catania 
  and 
  Valentia, 
  pub- 
  

   lished 
  by 
  Van 
  Rijckevorsel* 
  and 
  to 
  the 
  curve 
  derived 
  from 
  

   observations 
  made 
  in 
  Melbourne, 
  published 
  by 
  R. 
  J. 
  A. 
  Bar- 
  

   nard, 
  f 
  Because 
  of 
  its 
  simplicity, 
  the 
  Melbourne 
  curve 
  may 
  be 
  

   taken 
  as 
  a 
  demonstrative 
  example 
  of 
  the 
  problem 
  in 
  view. 
  

  

  From 
  the 
  highest 
  mean 
  temperature, 
  observed 
  in 
  January, 
  

   the 
  means 
  decrease 
  more 
  or 
  less 
  regularly 
  till 
  the 
  middle 
  of 
  

   March 
  ; 
  then, 
  suddenly, 
  temperature 
  increases 
  about 
  2° 
  F. 
  

   Another 
  characteristic 
  break 
  occurs 
  between 
  June 
  15th 
  and 
  20th. 
  

   After 
  the 
  minimum 
  of 
  July 
  the 
  increase 
  of 
  temperature 
  is 
  again 
  

   interrupted 
  in 
  September 
  and 
  also 
  at 
  the 
  end 
  of 
  November. 
  

  

  The 
  annual 
  variation 
  for 
  Melbourne 
  may 
  therefore 
  be 
  repre- 
  

   sented 
  by 
  the 
  following 
  diagram 
  (fig. 
  1). 
  

  

  Fig. 
  1. 
  

  

  This 
  diagram 
  expresses 
  graphically 
  the 
  opinion 
  that 
  the 
  sea- 
  

   sonal 
  change 
  of 
  temperature 
  in 
  Melbourne 
  is 
  not 
  what 
  it 
  should 
  

   be 
  : 
  that 
  at 
  given 
  dates 
  of 
  the 
  year 
  (a?, 
  y, 
  y\ 
  x') 
  the 
  natural 
  

   course 
  of 
  temperature, 
  due 
  to 
  local 
  conditions, 
  is 
  interrupted, 
  

  

  *Phil. 
  Mag. 
  (5), 
  xlv, 
  459, 
  1898. 
  

   + 
  Phil. 
  Mag. 
  (5), 
  1, 
  408, 
  1900. 
  

  

  