Smithsonian Report. 1930.- Babcock 



-^:--.^. 



Plate l 



1 . From a Phuiugkaph Made with Ordinary Light on a Panchro- 

 matic Plate with Light Yellow Filter 



2. From a Phoiockaph Madl Within jo i>ECONDS of Figure 1. but 

 WITH A Special Plate AND Filter so That Only Infra-red Radia- 

 tion IS Employed 



