UTAH ACADEMY OF SCIENCES 169 
It goes without saying that distribution is affected 
by the position of the shades. We find that by lowering 
the shades to where we usually find them in school 
rooms, i. e. about 1/3 down from the top, reduces the 
amount of light on the remote side of the room about 114 
times as much as it does when the window is entirely 
exposed, while the first row is affected very little. Frost- 
ing the upper part of the window reduces the difference 
on the last row somewhat. The important point to note 
is that shades, as usually hung, do not cut down the 
intensity on the side nearest the window ‘where the 
need for reducing is greatest, but they do very effectively 
reduce it on the remote side where even under the best 
conditions is there ever more light than is needed. Per- 
haps the ideal arrangement of shades would be to hang 
double shades at the center of the window so ithat 
either the upper or lower half could be covered as 
occasion requires. 
Distribution is affected by the height of the window- 
sill. For this study, a room in the new addition at the 
Summer school was selected and a comparison made 
with a room at the Liberty school. The height of the 
sill in the room at the Summer school was about twice 
that at the Liberty. The results show that the range of 
distribution in the Liberty school is nearly four times 
that in the Summer, which seems to indicate that high 
sills are better for evenness of distribution than are low 
sills. But this advantage is more than offset by the effect 
that high sills have on the feelings of the pupils and 
teachers who work in these rooms. The general senti- 
ment seems to be that high sills give a feeling of prison- 
like confinement. 
A secondary problem was considered in connection 
with those above because of its economic bearing on the 
subject of illumination with specia] reference to the 
relation of daylight to artificial light. It was found by a 
series of careful measurements that when artificial light 
is turned on in daylight that the resultant intensity is 
the sum of the two intensities. This is an important 
point in the matter of compensating for insufficient day- 
light which is more or less prevalent in school buildings. 
Thus, by employing the daylight factor for the first row, 
