SCIENTIFIC OFFENSIVE 



hot during the process of Hying apart, thus conforms 

 with this rule. 



Measuring the total emission of light of all kinds 

 was obviously desirable, since it would help to fix the 

 total amount of energy released in the explosion. Also, 

 it would help explain the flash burns to be produced on 

 test animals and equipment. Measurements were ar- 

 ranged by Commander S. S. Ballard and his colleagues 

 from the Naval Research Laboratory. This group, 

 called the Radiometry Subgroup of the Bureau of Ord- 

 nance Instrumentation Group, had laid its plans long 

 in advance. It had studied the optical radiation data 

 obtained in the previous year's test at Alamogordo; it 

 had estimated how greatly the absorption of Bikini at- 

 mosphere would differ from that of the dry atmosphere 

 of Alamogordo, and had then designed and build instru- 

 ments ideal for the job at hand. Principal reliance 

 was placed on bolometers and thermocouples, very 

 small devices which detect without discrimination light 

 rays of all kinds and directions. The received light pro- 

 duces small electrical changes, which are amplified and 

 ultimately cause small fountain pens to draw revealing 

 curves on long sheets of graph paper. 



Of principal interest to the spectroscopists was the 

 spectral distribution, or the relative amounts of light 

 of short and long wavelengths.* These men wondered, 



* In these optical studies the Naval Research Laboratory spec- 

 troscopists were assisted by spectroscopists from the Bureau of 

 Ships, the Army Air Forces, and various private institutions. 



75 



