288 



GROWTH OF PLANTS 



FiGUKE 113. Constant condition light room. 



humidity largely at 80 per cent. All plants except those groAvn under con- 

 tinuous illumination were kept on wheeled benches so they could be rolled 

 from the light to the dark room and vice versa to get the light day and night 

 desired. The plants were grown under 5, 7^ 12, 17, 19, and 24 hour daily 



time leave the OO2 in the gas, required a complex system of scrabbers. Planning and 

 building the scrubbers and determining the chemicals and other materials to be used in 

 the several units was a research problem in itself. Because of lack of space the reader ia 

 referred to the original article for details.® 



