NO. 14 EFFECTS OF INFRA-RED ON PLANTS — JOHNSTON 



3000 



4000 



5000 



6000 



7000 



8000 



Fig. I. — Sensitivity curve (continuous line) of a photronic cell provided witli 

 a special filter, and the visibility curve (dash line). 



Fig. 2. — -Curves showing the two types of energy distribution adjusted for 

 equality of " visible " radiation as measured by the photronic cell with its special 

 filter. 



