no. 3 



RADIATION OF THE ATMOSPHERE — ANGSTROM 



III 



The highest ascension of the series was made on July 30. This exceeds 

 the previous highest ascension from this continent by more than two kilo- 

 meters. The record obtained in this ascension is shown in figure 2. 



In seven of the ascensions from which records were returned the instrument 

 was carried to an altitude of 18 or more kilometers above sea level. The 

 temperatures recorded and the ascensional rates of the balloons have been 



Fig. 3. — Relation between ascensional rates of balloons and air temperatures. 



averaged and compared in table 2 and in figure 3. The mean of the 

 observed temperatures in the seven ascensions does not show a minimum of 

 temperature below the 18-kilometer level. The mean of the ascensional rates 

 of the balloons shows, in general, an increase with altitude. Above the 18- 

 kilometer level the individual ascensions show a decrease in the ascensional 

 rates of the balloons soon after the minimum of temperature has been passed 

 through. This relation between the air temperature and the ascensional rate of 



