22 
NATURE FOR ITS OWN SAKE 
Darkness 
of space, 
Other lights 
of the night. 
out from the direct light of the sun, and though 
far above the shadow, above the atmospheric 
arch we call the sky, the light streams through 
the realms of space, yet it leaves no visible track, 
no illumination, no reflection. Beyond our sky 
it is supposed there is no air, no vapor, no dust 
to catch and to reflect light. In space the sun’s 
rays travel direct with no diffusion, no halo, no 
radiation ; and could we see the sun itself it 
would appear as an intensely bright disk with- 
out shafts. It would seem then that, with sun- 
light and moonlight cut off, we gain little or no 
light from the upper regions of space, save that 
which comes from the stars. It is possible 
that our upper atmosphere may be illumined by 
reflected sun rays or moon rays, and that thus 
the light of the stars is helped out. And it is 
possible, too, that there is something of stored- 
up light or electrical phenomena to add to the 
night illumination. These accessories may aid 
the light of the stars somewhat, but they de- 
crease—the total illumination decreases—as the 
night wears on and out, and the darkest hour 
is just before dawn. 
So much for the direct and reflected lights 
of a summer’s day. It is one day out of 
three hundred and sixty-five, and has been de- 
