STEEP TRAILS 



band of cumuli will appear suddenly, coming 

 up the canon in single file, as if tracing a well- 

 known trail, passing in review, each in turn 

 darting its lances and dropping its shower, 

 making a row of little vertical rivers in the 

 air above the big brown one. Others seem to 

 grow from mere points, and fly high above the 

 canon, yet following its course for a long time, 

 noiseless, as if hunting, then suddenly darting 

 lightning at unseen marks, and hurrying on. 

 Or they loiter here and there as if idle, like 

 laborers out of work, waiting to be hired. 



Half a dozen or more showers may often- 

 times be seen falling at once, while far the 

 greater part of the sky is in sunshine, and not 

 a raindrop comes nigh one. These thunder- 

 showers from as many separate clouds, look- 

 ing like wisps of long hair, may vary greatly 

 in effects. The pale, faint streaks are showers 

 that fail to reach the ground, being evapo- 

 rated on the way down through the dry, thirsty 

 air, like streams in deserts. Many, on the other 

 hand, which in the distance seem insignifi- 

 cant, are really heavy rain, however local; 

 these are the gray wisps well zigzagged with 

 lightning. The darker ones are torrent rain, 

 which on broad, steep slopes of favorable con- 

 formation give rise to so-called " cloud-biu*sts " ; 

 and wonderful is the conmiotion they cause. 



366 



