36 



NATURE FOE ITS OWN SAKE 



valleys the lights and shadows seem to wave in 

 bands, like the streamers of the Northern 

 Lights across the sky. The shaking shimmer- 

 ing effect and the alternate colorings of yellow, 

 green, and gray, chasing each other across hill 

 and dale, are most extraordinary in appearance. 

 After watching them for a few moments, it is 

 quite impossible for the eye to tell whether the 

 light, the shadow, or the color is flying. At 

 other times, when the clouds are rounder and 

 larger, their shadows slip along majestically 

 from crag to lake, from lake to crag again, glid- 

 ing noiselessly and without obstruction up and 

 down and over the Scottish moors like dark peer- 

 ing spirits seeking a hiding-place and never 

 finding it. They roam restlessly on and on, until 

 at last they spread out upon the flat North Sea 

 and their dark forms, changed to lilac in hue, 

 go slipping over the waters to the east, still rest- 

 less, still noiseless, still flying. In other lands 

 the shadow is interesting to watch as it glides 

 across the meadows covered with buttercups 

 and daisies, and climbs the wooded mountains 

 to vanish over the ridge ; but the bare hills and 

 moors of Scotland always seem the best play- 

 grounds for the sun-burst and the flying shadow. 

 Light beams and flying shadows are some- 



