ARCTOWSKI, CHANGE):^ IN DISTRIBUTION OF TEMPERATURE 47 



to illustrate the fact (Figs. 2-5). These maps show perfectly a circular 

 movement in a clock-wise direction. This displacement is gradual and 

 the inspection of the maps leaves no doubt about the dynamic character 

 of the climatic change. It also appears evident that the phenomenon is 

 confined to the N^orth American continent : the macromeion takes the 

 place of the macropleion and both persist and stay on the continent : the 

 macropleion has been pushed over the West Indies and Mexico in order 

 to take the place of the macromeion over the western states, but has not 

 been pushed away, over the Atlantic, toward Europe or Africa. 



Fig. 2. — Macropleion. 1878-1887 



Fig. 4. ^Macromeion. 1880-1889 



Fig. 3. — Macropleion. 1879-1888 



Fig. 5. — Macromeion. 1881-1890 



The maps of the following consecutive decades again show a more or 

 less stationary situation and a gradual development of the macromeion 

 toward the south: for ] 883-1892 the departures are already negative in 

 the southern states and become more so for the decade 1885-1894. 

 Hence, a rotary movement of this macromeion, similar to that of the 

 macropleion of 1873-1882 and the following decades, would be expected. 

 This, however, is not the case. The displacement occurs, but in a pre- 

 cisely reversed direction. The western macropleion spreads out toward 

 the south, meets (1888-189?) a macropleion which progressively devel- 

 oped itself over the southern Atlantic states, and moves rapidly north. 



