H. H. Clayton — Seven Day Weather Period. 13 



parable results are found by allowing for the drift of the baro- 

 metric waves as previously found and adding several stations 

 together. Thus the results for Cheyenne are added to those 

 found one day later at Chicago and these to those found one day 

 later at Blue Hill. In this way a larger number of observations 

 is obtained and local influences are eliminated. In the same 

 way, allowing one day between each station, the results for Lesina, 

 Bucharest, and Perpignan, are added together. Those for Zi 

 Ka Wei and Tokio and for Batavia and Manila are added 

 with one day between, and those for Matanzas, Corrientes 

 and Rio Janeiro are added together, allowing one day between 

 the last and first two stations. The results are given in Table 

 lY under the headings of United States, Europe, Asia, 

 Oceanica and South America, and are shown in diagram 3. 







Table IY. 



















Day of Period. 





United States, 



1 



2 



3 



4 



5 



6 



7 



December-February, 



82 



100 



91 



80 



102 



100 



92 



March-May, 



82 



95 



81 



64 



108 



77 



85* 



June-August, 



70 



89 



76 



T6 



51 



61 



73* 



September-isrovember, 



90 



95 



75 



84 



109 



75 



74 



Europe. 

















December-February, 



61 



64 



58 



54 



62 



60 



50 



March-May, 



60 



T8 



60 



64 



71 



54 



67* 



June-Aug-ust, 



48 



65 



52 



T4 



53 



54 



62* 



September-November, 



57 



65 



60 



58 



64 



60 



52 



Asia. 













2i 





December-February, 



34 



35 



20 



29 



32 



23 



March-May, 



31 



35 



35 



33 



37 



35 



31 



June-August, 



22 



29 



20 



25 



22 



20 



23* 



September-November, 



32 



22 



31 



27 



34 



27 



34 



Oceanica. 

















December-February, 



24 



29 



23 



33 



22 



30 



34 



March-May, 



32 



36 



29 



31 



31 



36 



34 



June-August, 



19 



32 



23 



30 



30 



16 



27* 



September-November, 



32 



39 



22 



34 



38 



41 



22 



South America. 

















December-February, 



45 



52 



54 



38 



35 



55 



53 



March-May, 



49 



59 



57 



48 



54 



50 



47 



June-August, 



54 



55 



42 



62 



34 



42 



46 



^^ September-November, 



56 



55 



53 



50 



51 



70 



47 



^ The "Day of Period" at the top of Table IY has no further 

 significance than for use in reference. The curves in dia- 

 gram 3 begin on the third day of the table as arranged 

 above. These curves, at least for the northern hemisphere, 

 show a marked similarity for the same season in different 

 countries. In winter there are two maxima of storm fre- 

 quency, marked a and h in the diagram ; in spring a slight 



