PURE AND REFLECTED LIGHT 



21 



combination of color breaks and disappears, 

 some equally beautiful one takes its place. 



And when the sun and its cloud coloring have 

 gone, when the moon is not in our quarter, then 

 falls the night shadow upon the earth and 

 through it the shining of the stars. They, too, 

 are affected in appearance by the density or the 

 clarity of the air through which they are seen. 

 The night sky hanging over Sahara is usually 

 a very dark purple, but the stars do not shine 

 brightly upon it, and they have no marked col- 

 orings; yet they appear very near, as though 

 one might reach them with an arrow. Where 

 the air is more transparent, as in the north 

 of America, the night sky is deeper, the stars 

 sparkle and throw out tiny shafts of light, 

 and they show to the eye different hues of em- 

 erald, topaz, amethyst, ruby ; but they do not 

 appear to be at all near us. Jewels shining 

 through a dusky veil, they have but little light, 

 and that in such small points that the impres- 

 sion upon the great mass of shadow lying across 

 the earth is not great. We are able to see about 

 us on a starry night, but is it by the light of 

 the stars alone that we see ? Is that light suf- 

 ficient to illumine the world even in a feeble 

 way ? At night one-half of the globe is shut 



