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rain falling before and after January first, in each year since eighteen 

 hundred and forty-nine. The method which prevails in the plotting 

 is described in a note from Professor Becker, which we print below. 

 It will be noticed that heretofore an average of two-fifths of the rain 

 of the fiscal year has fallen before January first. While this would 

 give us a rather light total rainfall this year, if it conformed to the 

 average, it is also shown in the diagram that wide departures from 

 this rule have occurred in single cases heretofore, and we trust may 

 occur this year. The study of our rainfall is a practical one, and we 

 are under obligations to all scientific observers who give us data for 

 pursuing it. Professor Becker's note in relation to the diagram is as 

 follows : 



Messrs. Editors : To what extent the rainfall before the first day of January is proportional 

 to that of the whole season, is a frequent subject of discussion and is a matter of great practical 

 importance to the State. When Mr. Tennent published his valuable figures on the subject, in 

 the Bulletin of a few nights since, it occurred to me that it would be interesting to give this 

 relation of the partial rainfall to the total in a graphic form, and in such a manner that the 

 general proportionality, if it existed, and the relations for each year, would be apparent at a 

 glance. 



I make the following division of the rainfall in each year : 



RAINFALL IN SAN FRANCISCO.* 



*According to Tennent. 



Regent Davidson, nearly five years since, plotted Mr. Tennent' s figures for the purpose of 

 discussing the periodicity of the rainfall, but not in such a manner as to bring this special rela- 

 tion into prominence. In the accompanying diagrams each perpendicular line represents a 



