370 GENERAL SCIENCE 



much loss of light. It has been proved that a light buff tint is the 

 most satisfactory color for the walls of a school room. Dark- 

 colored woodwork and furniture with natural dull finish help to 

 reduce the reflection of light. Unvarnished surfaces, however, are 

 so difficult to clean thoroughly that for this reason the woodwork 

 is usually varnished. 



Smooth paper and paint reflect much more light, regardless of 

 the color, than a silky finish. Dirty paper, of course, reflects much 

 less light than clean paper. The following table will give some idea 

 as to the amount of light different materials reflect. 



Per Cent of 

 Material. Diffuse Reflection. 



White blotting paper 82 



White cartridge paper 80 



White cardboard 74 



Ordinary foolscap 70 



Chrome-yellow paper 62 



Cream paper 56 



Light-cream paint > 52 



Light-orange paper 50 



Pale-green paint 45 



Plain deal (clean) 45 



Yellow wall paper 40 



Yellow painted wall (clean) . . 40 



Light-pink paper 36 



Yellow cardboard 30 



Light-blue cardboard 25 



Brown cardboard 20 



Plain deal (dirty) 20 



Yellow-painted wall (dirty) 20 



Light emerald-green paper 18 



Dark-brown paper 13 



Vermilion paper 12 



Blue-green paper 12 



Cobalt-blue paper 12 



Dark-green paper 05 



Maroon paper . 05 



