NO. 6 



SOLAR RADIATION AND WEATHER CLAYTON 



43 



These means are plotted in figure 35. The side of the sun on 

 which the spot is located extends from about 6.5 days before to 

 6.5 days after the central passage of the spot, and the side of the sun 

 opposite the spot extends from about 7 days to 20.5 days after the 

 central passage of the spot. 



Fig. 35. — Solar radiation in relation to the position of spots on the sun. 



A continuous line connects the observed values, and a heavy broken 

 line shows the general sweep of the curve with the small oscillations 

 smoothed out. It is seen that the side of the sun with spots averages 

 colder than the opposite side. There is a tendency, however, to a 

 lower value of the solar radiation on the part of the sun exactly 

 opposite the spot, thus tending to divide the solar rotation into two 

 periods. Examining the shorter oscillations, a marked depression 



