130 



TABLES AND RESULTS OF THE PRECIPITATION, 



Type III. — Upper Mississippi River, from Fort Madison, southern Iowa, to Fort Ripley, central 

 Minnesota, and including part of Wisconsin. 



Characteristics : A principal maximum about the end of June, a secondary maximum about the middle of Sep- 

 tember, and a principal minimum about the beginning of February. Range, tolerably large. 



. 



t 



B 





„ 





c 

 







"a 1 



i S2 



"g S 



Mean 



p 





5 S H"!" 







§ u 



of 6 

















i 

 Pi 



1 £■ I 



: s if 



3 " 





s<2 



Stations. 



January- 



34 



41 



65 



.62 



5i 



•57 



•52 



February 



3° 



2 5 



.S3 



•53 



69 



■77 





51 



March 



64 



58 



76 



•78 



88 



.86 





75 



April 



77 1 



11 



«3 



1.08 1 



21 



1.08 



I 



01 



May i 



39 1 



42 1 



32 



1.29 1 



25 



1.23 



I 



32 



June 2 



00 1 



73 1 



64 



1.40 1 



34 



1.25 



I 



S6 



July i 



90 1 



74 1 



45 



i-33 1 



°5 



1.24 



I 



45 



August i 



3i 1 



42 1 



06 



1.08 1 



48 



1.23 



I 



26 



September i 



66 1 



63 1 



38 



1.28 1 



i 1 ? 



1-35 



I 



40 



October 



68 



63 1 



11 



•93 



Q5 



.91 





87 



November 



68 



7i 



76 



• 94 



81 



•78 





78 



December 



34 



39 



5o 



.76 



7i 



•7i 





57 



The curve is derived, on the aggregate, from 114 years of observation; it does 

 not materially differ from that of Type II; the maximum in October appears now 

 shifted into September, and the whole range of the variation is increased. Com- 

 paring the curves individually, there is a tendency to a single maximum, the earlier 

 of the two ; at one station they appeared to merge into one, and at another, the later 

 maximum is higher than the earlier one. More observations are required to render 

 this type more perfect. 



Type IV. — Ohio River Valley ; from Alleghany Arsenal, western Pennsylvania, to St. Louis, 

 eastern Missouri. 



Characteristics : One principal maximum, and one principal minimum ; the former early in June, the latter early 

 in February. Range, moderate. 

























Month. 



£ £ * 



c a 



g *■» 



si 



CO 



£ >■ 



6 rt 



•gR, 



it i 





| 2 I 

 ►4 Si >> h 

 -•<? * 



to a 



1 £ 

 . CO 



5" 



s s s 



Mean 



of 9 



Stations. 



January 



.70 



•85 



.82 



.82 



.90 



76 



•56 



59 



.67 



•74 



February 





73 



•79 



.86 



■85 



■93 



67 



■63 



73 



•63 



.76 



March 





88. 



.98 



.90 



.98 



•97 



78 



I.09 I 



07 



.88 



•95 



April 



1 



07 



1.02 



■99 



.98 



•97 1 



2.5 



1. 14 I 



10 



.92 



1.05 



May 



1 



2 5 



1. 11 



1. 16 



1. 17 



1.23 1 



47 



i-39 1 



37 



!-37 



1.28 



June 



1 



3 1 



1. 16 



1.22 



1.20 



1.22 1 



73 



1.82 1 



48 



1.46 



1.40 



July 



1 



04 



1. 12 



1.25 



1. 12 



1. 10 1 



02 



1. 14 1 



11 



1.40 



1. 14 



August 



1 



14 



r -IS 



1. 11 



I - I 3 



1.04 



go 



.98 1 



11 



JI 3 



1.08 



September 





90 



I. OI 



.88 



.90 



•73 



99 



.69 



88 



.96 



.88 



October 





95 



.92 



.92 



.88 



.84 



76 



.90 



87 



.91 



.88 



November 





93 



.91 



.89 



.91 



•94 



84 



.91 



^ 



•95 



.90 



December 



1.09 



•97 



I.OI 



1.06 



i-i3 



84 



.76 



86 



•7i 



•94 



The Type-curve IV is derived, on the aggregate, from 249 years of observation. 

 The individual curves show considerable deviations in the time of the principal 

 maximum and in the amount of the secondary maximum. 



