26 



NATURE FOB ITS OWN SAKE 



The lower y 

 lay. 



will have its light-and-shade like any other 

 object, and the dark massed nimbus, which we 

 call the rain cloud, is not very different from 

 other clouds, save that its base is deeper sunk 

 in shadow. 



The gray, lowery day, so often seen in spring 

 and winter, shows us cloud forms so closely 

 packed together that they make a continuous 

 curtain across the sky, through which light 

 passes to the earth in a neutral but widely dif- 

 fused illumination. This is broken light in its 

 most positive form. Dispersed in every ray by 

 moisture particles, the crippled sunlight can do 

 no more than throw a gray monotone over the 

 face of nature, taking the cloud coloring for its 

 chief note. Such a day is usually declared 

 "dull." The sky and sun are completely shut 

 out, there is no sharp flash of light, color, or 

 shadow, no mellow haze upon the earth, no 

 gilding and fretting of gold overhead. The 

 cloud curtain covers the sky and draws down 

 below the horizon-ring like a cap, a film of mist 

 lies across the meadows, blue and purple drifts 

 of air float high up in the valleys, and along 

 the mountain-sides and over the craggy peaks 

 hang gray fringes of rain. Upon days like 

 these the clouds troop on across the sky, rank 



