62 



Kansas Academy of science. 



TABLE No. 2. — Seven-year periodicity in rainfall. 



Length of 

 record. 



Omis- 

 sions- 

 years. 



No. 

 periods. 



Fail- 

 ures. 



One- 

 half 

 fail- 

 ures. 



New Bedford, Mass . 

 Philadelphiu. Pa. . . . 



Providence, R. I 



Boston, Mass 



Leavenworth, Kas... 



Rochester, N. Y 



Toronto, Can 



St. Louis, Mo 



Marietta, Ohio 



Cincinnati, Ohio .. . . 

 Muscatine, Iowa 



1814--90 

 1824-'90 

 1832-'90 

 1818-'90 

 1836--90 

 1831-'90 

 1840-'90 

 1837-'90 

 1826-'90 

 1835-"90 

 1846-'90 



Total. 



Table No. 2 gives the results of the investigation. Column 1 gives the name of 

 the plaee where the observations were taken; column 2, the date of the beginning 

 and ending of the record; column 3, the number of years of the record in which ob- 

 servations were not taken; column 4, the number of seven-year periods in the rec- 

 ord; column 5, the number of whole failures; and column fi, the number of half 

 failures. 



To illustrate what we mean by a failure and a half failure, take three of the Fort 

 Leavenworth means, viz., 33.82, 34.03, and 43.16. The second of these is greater 

 than the first, and is therefore wet with respect to the first; but it is less than the 

 third, and hence is dry with respect to the third. This is a half failure. If the sec- 

 ond mean were greater than the first and third, when it should be less than both, it 

 would be a failure. 



Examining Table No. 2, we see that there are only three failures and 12 half fail- 

 ures in the 82 seven-year periods of these 11 places. 



