CLOUDS AND CLOUD FORMS 



83 



They rise, fall, or change before our eyes 

 with no effort, no sound, no apparent design. 

 Now they are scattered wide over the blue, now 

 they are huddled together and driven in flocks 

 by the wind ; but they never seem to be in a 

 hurry. An epitome of idle content, having 

 no actual power in themselves, they are, never- 

 theless, the visible sign of aerial energy. The 

 wind blows them whither it listoth. They drift 

 around and about the world and have no abid- 

 ing-place, no resting-place on land or sea ; yet 

 wherever they go they gladden the eye and 

 cheer the heart, and in every landscape they 

 are the bright spots of beauty. 



And what wonderful luminosity there may 

 be in a cloud ! The upper cirrus just before 

 sunset is often dazzling in its light, and when 

 struck full by the sun's rays, there is nothing 

 more intense in luminosity than the cap of the 

 tall cumulus. The ancients felt the splendor 

 of this cloud light, and it is not strange that 

 the Old Testament writers should speak of the 

 "pillar of cloud" that guided the wanderings 

 in the wilderness, of God descending on a cloud, 

 of a cloud as the resting-place of the Mercy 

 Seat and the standing-place of angels. The 

 purity of these white vapors of the upper air 



