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NATUKE FOE ITS OWN SAKE 



feet above the earth, and though its movement 

 is hardly perceptible to the eye, it may be drift- 

 ing at the rate of fifty miles an hour. Its effect 

 in making a hazy day is quite noticeable, and 

 at sunset, when it lies across the western hori' 

 zon in bars, it is often very pronounced in reds 

 or chrome-yellows. 



The strato-cumulus (a) is another and per- 

 haps more common form of the stratus. It is 

 a heavier variety, darker in color, and more 

 roll-like in form, caused by its having about it 

 something of the lumpy nature of the cumulus, 

 yet with enough of the stratus to make it form 

 in a layer along the sky. It is a cloud that 

 may send forth rain, though it often overhangs 

 the earth in dark folds for days at a time with- 

 out giving forth a drop. At times it looks like 

 a compact, dense rain cloud, and when it as- 

 sumes this shape it is often confused with the 

 nimbus. 



CUMULUS (3) is the name given to any cloud 

 that has a heaped-up, mountainous, or lumpy 

 look about it. The white patches that bowl 

 across the sky on a summer's day are detached 

 portions of cumulus ; but the most noticeable 

 form of it is the " heap " cloud that on warm 

 afternoons lies off in the southern sky, rising 



