DIRECT AND INDIRECT LIGHTING 
143 
For the indirect system silvered reflectors of the opaque bowl 
type were used, and thus no light passed directly from the light 
sources to the printed page. They were hung about two feet 
below the ceiling. In this case the yellow window shades were 
pulled down so as to augment the reflected light. Gas-filled lamps 
were used in both cases. The value of the current which it was 
necessary to put through the lamps in order to get the illumina- 
tion approximately the same in the two cases was ascertained by 
a preliminary test. At the same time the current was so adjusted 
as to produce a variation in lighting intensity from one which was 
too low for comfortable reading to one which was too high. There 
were twenty-six individuals, all college seniors. The following 
instructions were given them. 
DIRECT AND INDIRECT LIGHTING 
No. Name Date 
Turn to a regular page of print in your text and ask yourself 
whether you could probably read this comfortably (without strain 
on your eyes), throughout the evening, when any one system and 
condition of lighting is used. In designating the impression of 
intensity of illumination on your book, use one of the following 
terms if possible: 
Much too low 
Somewhat low 
Acceptable, but prefer more 
Just right 
Acceptable, but less would do 
Somewhat high 
Much too high 
Brief comments on the lighting intensity will be appreciated. 
Keep the book on the arm of the chair and sit in a natural posi- 
tion while reading. On leaving the room leave this sheet on the 
seat of your chair. Do not change the position of your chair 
when once you have begun to note down observations. 
DIRECT 
1 
2 
3 
4 
5 
INDIRECT 
1 
2 
3 
4 
5 
