438 



R. W. ESTABROOK 



©Tungsten or 

 high pressure 

 Hg arc lamp 



Fig. 1. Schematic description of the wavelength scanning recording spectro- 

 photometer developed by Chance (1951). 



split light beam 

 from 

 30 c p s 

 oscillating mirror 



adjustable (sliding) 

 cuvette holder 



liquid air 



Fig. 2. Detail of the cuvettes and holder used for low temperature 

 spectrophotometry. 



