ARCTOWSKI, CHANGES IN DISTRIBUTION OF TEMPERATURE 85 



The question is whether this antipleion, extending from Alberta to Lower 

 California, came from the Pacifie or is the southeastern antipleion of 1901 

 which moved across the States. 



Nineteen hundred and three is a year of a predominant antipleion 

 covering nearly the entire area of the United States and extending north 

 and south into Canada and Mexico (Fig. 25). The most negative de- 

 partures are — 2°A at Grand Junction and — 2°. 8 at San Antonio. 

 This antipleion has a third center in South Dakota and resembles in 

 shape that of the preceding year. A close inspection of the maps gives 

 the impression of a contra-clockwise movement. 



If this hypothesis is justified, it must be admitted tliat tlie map of 

 1904 (Fig. 26) expresses the result of the continuation of this circular 

 displacement. In 1904, the center of the antipleion is in the northeast 

 of Lake Huron, with a departure of — 3°.-i at Parry Sound. In the 

 west, on the contrary, there is now a pleion which, in this hypothesis, 

 would also have traveled contra-clockwise, from Ontario towards Idaho. 



The western pleion has two centers with -f 1°.9 departures at Helena, 

 Mont., and Independence, Calif. The map displays a very accentuated 

 contrast between the temperatures in the west and in the east and is 

 perfectly typical. 



In 1905 (Fig. 27), we have again negative departures all over the 

 States with the exception of Florida, California and parts of \Yashington, 

 Montana and Xorth Dakota. In Alberta, there is a pleion with de- 

 partures as high as + 2°.9 (Battleford) and the same pleion extends over 

 the Pacific, the departures along the coast being -f 0°.5 in Port Crescent, 

 Wash., and + 0°.8 in Eureka, Calif. In 1904 the departure was -f 0°.l 

 in Bermuda, now it is + 0°.6 and it is this Atlantic pleion which extends 

 from Bermuda over Florida towards the Gulf of Mexico. It seems that 

 the change of the map of 1904 into that of 1905 was due to a displace- 

 ment of the antipleion from northeast towards the southwest, accom- 

 panying a displacement of the pleion from the west towards the north. 

 The movement was contrary to that of the preceding year, both the pleion 

 and antipleion remained on the continent and traveled around in the 

 same direction as the hands of a clock. 



The year 1906 shows a continuation of this movement, at least as far 

 as the pleion is concerned (Fig. 28). 



In 1907, on the contrary, the conditions are so very different from 

 those of 1906 that it is absolutely impossible to make any statement about 

 the displacements which took place between these two years. The map 

 of 1907 (Fig. 29) is precisely the reverse of that of 1906. Where there 

 was an antipleion there is now a pleion and vice versa. The disposition 



