ILLUMINATION 



367 



railroads and elsewhere, although it is really a poor color lor this 

 purpose. Pure, deep red allows so little light to pass through that 



Bust lighted from above and The same bust lighted from 

 in front. directly overhead. 



FIG. 257. Bad lighting defeats good art. 



it is impracticable. Green would have been the better signal for 

 danger, since it can be more easily seen than red. 



Per Cent of 

 Material. Transmitted Light. 



Clear glass 100 



Canary 82 



Ruby. 13.1 



Bottle green 10.6 



Bright green (signal green No. 2) 19.4 



Bluish green (signal green No. 2) 6.9 



Cobalt blue 3.7 



For ordinary illumination white or yellowish white is desirable. 

 Blue or green tinges in the light give a cold, hard hue to objects 

 in general, and also give an unnatural pallor to the face. 



