INDOOR ILLUMINATION 



247 



hence undergoes diffuse reflection, and is scattered irregularly 

 in all directions. No matter where the eye is, some reflected 

 rays enter it, and the various objects are clearly seen. 



Indoor illumination. We see objects by means of light 

 which comes from them to our eyes. If an object, such as a 

 picture, is well illumi- 

 nated, it reflects light 

 to the eye, and we see 

 it distinctly. If it is 

 poorly illuminated, it 

 reflects little light to 

 the eye, and we see it 

 indistinctly and with 

 effort. Objects do not 

 all reflect light equally 

 well. A white object 

 reflects most of the light 

 which falls upon it and 

 a moderate illumination 

 is sufficient to light up 

 a table with a white table cover. A black or dark object reflects 

 light badly, and a strong illumination is necessary to light up 

 dark stairways and darkly papered walls (Fig. 117). A light 

 that would be strong enough for sewing white materials would 

 be far from sufficient for sewing black or dark materials. A 

 room that receives little light from out of doors should be 

 brightly papered and furnished, otherwise it is somber, furni- 

 ture does not stand out, and reading and sewing in it cause eye- 

 strain. We are not always conscious of the strain on the 

 eyes from working on badly lighted materials, but the strain 

 exists and the eyes suffer. A sunny room, or one well lighted, 

 does not need such bright paper, curtains, and furnishings, and 

 can be arranged in darker colors without injury to the eyes. 



FIG. 117. These two rooms receive the same 

 amounts of light. The room at the left has 

 dark walls and the one at the right has light 

 walls. 



