22 



NATURE FOR ITS OWN SAKE 



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- 



