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



November, and storm frequencies were determined for each 

 day of the seven day period. The results for a few stations, 

 separated as widely as possible, are given in Table III. 





Table III 





















Day 



3f Period. 





Chicago, 



1 



2 



3 



4 



5 



6 



7 



December-February, 

 March-May, 

 June-August, 

 September-November, 



23 



22 

 18 

 24 



33 

 35 



22 

 3T 



27 

 22 

 16 

 24 



26 

 25 

 23 



27 



23 

 34 



22 

 27 



39 

 23 

 30 

 31 



26 

 22 

 23 

 25 



Bucharest, 



1 



1 



2 



3 



4 



5 



6 



December-February, 

 March-May, 

 June-August, 

 September-November, 



13 

 10 

 12 

 13 



18 

 23 

 20 

 IT 



12 



9 



10 



14 



8 

 20 



16 

 16 



20 



17 

 15 

 17 



13 

 18 

 18 

 13 



16 

 15 

 12 

 12 



Zi Ka Wei, 



2 



3 



4 



5 



6 



7 



1 



December-February, 

 March-May, 

 June-August. 

 September-November, 



12 



16 



12 



9 



12 

 17 

 12 

 16 



10 

 14 



6 

 9 



10 

 14 

 14 



15 



14 



14 



9 



15 



14 

 17 



10 

 5 



5 

 15 



9 

 12 



Batavia, 



1 



2 



3 



4 



5 



6 



7 



December-February, 

 March-May, 

 June-August, 

 September-November, 



21 

 25 

 17 



28 



24 

 26 

 26 

 34 



19 

 20 

 17 

 20 



28 

 24 

 26 

 29 



17 

 23 

 28 

 32 



24 

 28 

 14 

 40 



30 



24 

 22 

 22 



Matanzas, 



2 



3 



4 



5 



6 



7 



1 



December-February, 

 March-May, 

 June-August, 

 September-November, 



n 



19 

 25 

 23 



23 

 2T 

 2T 

 23 



22 

 24 

 15 

 22 



16 

 22 

 23 



20 



16 

 23 

 22 



20 



26 



23 

 20 

 30 



26 

 24 



20 

 19 



Flagstaff, 



7 



1 



2 



3 



4 



5 



6 



December-February, 

 March-May, 

 June- August, 

 ■ September-November, 



9 



7 



10 



9 



7 

 10 



11 



8 

 8 

 6 

 6 



7 



7 



8 



14 



9 



8 

 8 



7 



6 

 9 



7 

 6 



9 

 8 

 1 

 9 



The data in the table are so arranged that what appear to be 

 corresponding days at all the stations come under one another, 

 the day of the period being given above the data for each 

 station. 



The heavy-faced figures showing the maxima render it 

 apparent that there is a tendency at every station for the 

 days of maximum frequency to remain on the same days 

 of the period throughout the year. Thus at Chicago the 

 maxima tend to occur on the second and between the fifth and 

 sixth day of the period ; at Bucharest they tend to occur on the 

 first and between the fourth and fifth day of the period, etc. 



If, however, the curves are plotted they show considerable 

 irregularities and dissimilarities. Smoother and more com- 



