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Rural Schuul Leaflet. 



named from the appearance they present, Some of the kinds of clouds 

 are shown in the ilkistrations. The upper clouds are called cirrus 

 (Fig. 37). They are white, thin, and fibrous or hair-like, which gives 

 them the name of "horse-tails." Sometimes they look like great white 

 feathers or plumes. They are usually seen a day or two before a storm. 

 When the storm comes nearer, the cirrus clouds become thicker, cover- 

 ing the whole sky. They are then called cirro-stratus clouds. (Fig. 

 35). Sonietimes they form in rolls or balls, and look very much like 

 bundles of wool. They are then called cirro-cumulus. These clouds in- 

 dicate rain or snow within eighteen to thirty-six hours. It is the cirro- 

 cumulus clouds that the sailors call the "mackerel sky," because the 

 cloud-rolls or balls are said to look very much like a school of mackerel. 



The cumu- 

 lus clouds are 

 lower clouds. 

 (Figure 38). 

 They are usu- 

 ally seen in 

 the summer 

 time before 

 a thunder- 

 storm, and 

 are sometimes 

 called " thun- 

 der- heads." 

 They are 

 thick, dense 

 clouds with 



Fig. 38. — Cumulus. 



great round- 

 ed, castle-like 

 tops and usu- 

 ally straight 

 bases. 

 Stratus clouds are thick, and of a darkish gray color. Sometimes 

 they are not much higher than the tree tops, and are usually below the 

 tops of mountains. If you were on top of a high mountain, you could 

 look down on the upper side of the stratus clouds. Stratus clouds are 

 the rain-bearing clouds, but as soon as the rain begins to fall from the 

 clouds the name changes to nimbus, (Fig. 36) the rain cloud; for the 

 nimbus cloud is a cloud from which rain is falling. 



I want you to watch the clouds every day for a week. Ask your 

 teacher to help you to learn to know them by their names. If there are 

 any that you cannot name, write out just how they look to you, and mail 

 your letter to the Cornell Rural School Leaflet. 



