212 TABLES AND RESULTS OF THE PRECIPITATION, 



Locality. 



Maine 



New Hampshire .... 



Vermont 



Massachusetts & Connecticut 



Rhode Island 



New York 



New Jersey 



Pennsylvania 



Delaware, Maryland, and 

 District of Columbia . 



Virginia 



North and South Carolina . 



Georgia 



Florida 



Alabama 



Mississippi and Louisiana . 



Texas 



Arkansas 



Aggregate 



Days. 



years. 





89 



93 



15 



76 



26 



89 



26 



98 



50 



96 



214 



109 



12 



118 



93 



119 



58 



83 



37 



85 



52 



89 



18 



83 



77 



91 



17 



98 



50 



92 



III 



58 



15 



75 



Locality. 



Kentucky .... 

 ; Ohio 



Michigan .... 



Indiana and Illinois . 



Wisconsin .... 



Minnesota .... 



I Iowa 



I Missouri .... 



Indian Territory . 

 i Kansas 



Nebraska .... 



Wyoming .... 



New Mexico' . 

 I Arizona .... 



California'' .... 



Oregon^ .... 



Washington Territory' 



Alaska 



Aggregate 

 years. 



118 



87 

 10 

 48 



47 

 19 

 49 

 60 



43 



47 

 8 



47 

 16 



19 



14 



Days. 



116 

 117 

 107 

 89 

 89 

 98 

 70 



73 



77 

 75 

 72 



56 



75 



50 



131 



132 



23s 



At Toronto, Canada, the number of rainy and snowy days averages 162 in a 

 year, as derived from 23 years of record; at Hamilton, Canada, ten years of record 

 gave 122 days. 



For Colorado, Dakota, and Utah, from three, four, and one year of record, we 

 have 51, 72, and 102 days of precipitation, respectively. 



From the above table, and by means of the ratios of amoimt for each month, 



compared with the mean amount, we can readily deduce the probable number of 



rainy days in any given month ; thus, for the month of May, in the State of New 



109 

 York, for instance, we have the average number of rainy days in a month = — — 



by preceding table, and the monthly ratio 1.14 from Table, Type II, hence, number 



109 

 of rainy days to be expected in May := 1.14 times —— = 10. 



I/& 



The aggregate number of years upon which the average num ers for rainy and 



snowy days of the preceding table depend is 1620. 



SECULAR CHANGE OF THE RAIN-FALL. 



The question whether the annual rain-fall is gradually increasing or diminishing, 

 stationary, of a periodic character, or apparently irregular, is one of great interest, 

 scientifically as well as practically. The preceding table B has been specially pre- 

 pared for the investigation of these changes of the annual amoiuit of rain, and if 

 these records sliould not be of sufficient extent, they will at least form a basis for 



' Average very uncertain, the precipitation depending too much upon the elevation and otlier 

 circumstances. Number of rainy and- snowy days vary between 31 and 93. 



^ The extremes, Fort Yuma 11 days, and Fort Humboldt 82 days, also Fort Crook 83 days, are 

 not included in the tabular mean. Average hardly admissible without further specification, as in the 

 case of New Mexico. 



' Averages uncertain without specification. 



