Smithsonian Report, 1932. — Russell 



PLATE 1 



1. A Vacuum spectrograph used for Studies in the Extreme Ultra- 

 violet Region of Light 



It was developed from a design of Prof. Karl T. Compton, of Massachusetts Institute of Technology, 

 with the assistance of Dr. Joseph C. Boyee, a research associate in the department of physics. It 

 is in the spectroscopic labcrUory at M. I. T., a ".science wonderland," which "represents the" heaviest 

 artillery yet concentrated by science for assaulting the citadel of the atom." 



2. The Great 21-Foot Vacuum Spectrograph at M. 1. T., the Largest 



Ever Built 



It was designed by Prof. George R. Harrison, director of the spectroscopic laboratory. When the 

 cylinder is evacuated, the force exerted by the atmosphere on the outside is approximately 88 tons. 

 The size of this huge spectroscope is indicated by comparing it with the one on the table which is of 

 the size customarily used in this field of research. 



