NO. 4 SOLAR. RADIATION ABEOT, FOWLE, AND ALDRICH 



45 



the lighting current was cut off intermittently to prevent premature 

 exhaustion of the battery. Unfortunately the mechanism failed to 

 make electrical contacts in the region A 2 A z , so that the pyrheliometer 



A^ 



B 



iipiiiiiliiiiii 



Mi! 



B„ 



B, 



1 lf| : *':! : 

 4: i.«tt|«J| «4»*-l» 



A 



!. 



j i 

 |i! 



Fig. 8. — Night Record with Balloon Pyrheliometer. 



record is missing there. It does not show in the last part of the 

 record corresponding to A 3 A±, from which we infer that the electrical 

 heating proved insufficient to hold the temperature of the disk above 

 about — 15 , corresponding to the position C, and .that the record 



