PURE AND REFLECTED LIGHT 
15 
the surface of the earth, they pass through 
many miles of this heated dust-and-moisture- 
laden air. When they reach our eyes they tell 
the oft-told tale of the brilliant sunset. The 
pale grays and silvers of the dawn, produced by 
the sun’s rays coming to us through a cleared 
and cooled atmosphere, have now changed to 
the golds and scarlets of the evening, produced 
by the rays coming to us through a heated and 
a thickened atmosphere. So dense is the air at 
times that the shafts of the setting sun may be 
distinctly seen radiating up the sky like the 
spokes of an enormous fiery wheel ; and again 
at other times the air may be so thick that it 
obscures the sun’s rays, and we can see the red 
disk go down almost without a flash of light as 
though its own heat had consumed it. 
The glare and heat of sunset colors are per- 
haps more apparent than real. The same sun 
at the time it looks red to us may show the 
yellow of noon and the white of dawn to the 
people and the lands lying to the west of us. 
We are looking from a land of shadow toward 
one that is still in full sunlight, and the bright- 
ness of the sky-color is great by contrast. The 
colors and combinations of colors that we see 
on the western sky and clouds at sunset and 
The sunset. 
Red sun 
disks. 
Sunset 
colors. 
