TWENTY-THIBD ANNUAL MEETING. 



167 



inches : ichich makes a difference in favor of the first half of .218 inch per annum . Sup- 

 pose we divide the jieriod into quarters — 



Total Yearly 



rainfall, average. 



First iinarter 245.16 30.645 



Second quartM- 222.99 27.874 



Third quarter 257.08 32.12 



Fourth quarter 250.94 31.36 



This shows an excess in the third quarter, and a deticiency in the second — surely 

 nothing like what we would expect if we are getting a regular increase in our rain- 

 fall. "Is the rainfall increasing?" I hope so, truly, but am free to say I don't 

 know. I don't believe the record proves either that or the converse. 



As regards the popular idea that we have a rainfall cycle of seven years, this rec- 

 ord does not show that either. It will be noticed that the period from the beginning 

 of the record up to 1866 was very irregular, was one of ups and downs, alternate 

 years being on opposite sides of the average line. Then comes a cycle of seven 

 years, from 1865 to 1872; then another of four years: then one of seven years again, 

 and then one of uncertain duration not finished yet. and which, including 1890, is 

 eight years old and still on the downward trend. The record shows a variation that 

 I think proves nothing, excepting that there is no jieriodic law that can be depended 

 on in the rainfall at Manhattan. 



The g]"eatest rainfall for any one month was for July, 1878, being 12.71 inches. 



The monthlv means, in inches, are as follows: 



January 75 



February 98 



March 1.16 



April 2.75 



May 3.93 



June 4.39 



July 4.65 



Augu.st 3.86 



.September 3.19 



October* 2.23 



November '. 1 . 47 



December 87 



This table shows a gradual and steady increase from January, the month of least 

 precipitation, to July, that of the greatest, and from then a steady decrease. 



The diagram below exhibits clearly the variation in the rainfall at Manhattan. 



RAINFALL, AT MANHATTAN, KANSAS, 1858-90. 



58 59 60 01 6-2 63 64 65 66 67 68 69 70 71 72 7:$ 74 75 76 77 78 79 80 81 S'2 8:J 84 85 86 87 88 89 »0 



■l.'>.bC/ 



WIND VELOCITY AT MANHATTAN, KANSAS. 



BY C. M. BKEESE. 



The record of the wind velocity at Manhattan only extends back to February. 

 1889. 



The upper curve shown in the diagram shows the mean velocity of the wind for 

 each hour of the day during the first nineteen months of the record. The figures 1, 



* These means include the first ten months of 1890, and consequently their sum does not exactly 

 afcree with the average of the chart. 



