22 



graph given ty Kimballv farr the maximum possible total ra- 

 diation received per day at Moimt Weather , Virginia. Since 

 this station is at about the sp.me latitude as the stations 



Kimball, Herbert H. , ^he total raiia-ion received on 

 a horizontal surf'ace from the sun and sky at Mount Weather, 

 Monthly Weather Rev. 42; ^74-487. 1914. (See especially fig. 

 8, p. 484). 



here dealt with, the ordinate from Kimball's graph may be 

 taken as approximate measures of the total maximum possible 

 light intensities for the corresponding dates for all of the 

 Maryland stations, '"hese values represent the total amount 

 of heat received from the sun and sky on niear days at 

 Mount Weather, in gram-calories per square centimeter of a 

 horir.ontally exposed surface. The method of using this graph 

 and the weather observer's reports, for estimating sunshime 

 intensity for any station and period, will be best shown by 

 an example. Suppose it is desired to estimate the average 

 daily sunshine intensity for some sta'"ion in the general 

 region of Mount Weather, for the first v;eek of August, '^he 

 average ordinate value for this week is first obtained from 

 Kimball's graph. For leriods as short as a week or two this 

 may be done by averaging the values for the first and last 

 days of the period, since the curve may be taken as a 

 straight line for such short intervals, "^rom the report of 

 the weather observer at the ;flace in question, the number of 



