PURE AND REFLECTED LIGHT 
19 
higher in the evening sky and gets out of the 
range of this heavy air lying along the earth, 
the disk apparently grows smaller and becomes 
clearer in light. The red and orange fade out, 
and we see what is called the ‘ yellow moon.” 
It grows still fainter as it rises toward the zen- 
ith and the earth’s atmosphere clears and cools ; 
and when in the morning hours it sinks into 
the west, the disk is whitened and apparently 
shrunk in size. There is little color demonstra- 
tion as it nears the horizon again. It is cool 
and silvery, seldom red or yellow, and slips 
from view usually unnoticed. 
Moonlight is, of course, the light of the sun 
reflected from the moon. It is not reflected 
from a bright surface like water (there is no 
water on the moon) but from dull surfaces like 
rock ; and as a result the reflection is many de- 
grees feebler than its cause. Yet the moon has 
some surface gleam about it and is hardly like 
an illuminated transparency hung in the air. 
By comparison with the sun it has no sharp 
shafts and is so feeble that when sun and moon 
are both above the horizon the latter attracts no 
attention whatever ; but after the sun has gone 
down and the moon rising in the east mingles its 
light with the twilight of the west, it makes a 
The yellow 
moon. 
Tuilight 
and moon- 
light 
blended. 
