ARCT0W8KI, CHANGES IN DISTRIBUTION OF TEMPERATURE 91 



1903-1904. The map of 1904, without a doubt, expresses the con- 

 tinuation of this dynamic phenomenon. The change, however, in the 

 respective positions of the two centers is not progressive. The following 

 four maps (Figs. 38^1) show indeed that for February, 1903,-January, 

 1904, the temperature conditions were still veiy similar to those of 1903, 

 whereas for April, 1903,-March, 1904, the distribution of the negative 

 departures already had the character of the map of 1904. The develop- 

 ment of the western pleion was delayed, and it is only on the consecu- 

 tive map ending in November that its maximum development is reached. 











V,.>m->-':--:^-.;;!tT,f r ' 



Fig. 38.- — Departures of temperature 

 averages for February, 1903 -January, 

 1901, 



Fig. 40. — Departures of temperature 

 averages for April, 1903,-March, 1901, 



Fig. 39. — Departures of temperature 

 averages for March, JS03,-February, 

 1901, 



Fig. 41. — Departures of temperature 

 averages for May, 1103 -April, 1901, 



1904-1905. The consecutive maps showing the transformation of the 

 temperature conditions of 1904 into those of 1905 are nu:)st interesting, 

 because they show a slow and continuous movement. The pleion and 

 antipleion remain bound together and both remain on the continent; 

 but the displacement is reversed and now it goes clockwise. The follow- 

 ing two diagrams (Figs- 42-43) will be sufficient to demonstrate inter- 

 mediate stages between 1904 and 1905. The first one is of the twelve- 



