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Stratus cloud that halos, parhelia, paraselene, &c. are 

 formed. 



The Cirro- Cumulus, or warm-weather cloud, attends 

 a rising barometer. This pretty modification is often 

 formed from the Cirrus. The Cirro-Stratus will also 

 frequently after rain dissolve into Cirro-Cumulus, an in- 

 dication that the frozen mass of which the Cirro-Stratus 

 is formed is thawed on its descent into a warmer atmo- 

 sphere ; where becoming attenuated, it breaks and split*, 

 leaving clear blue sky between the small round patches 

 of cloud, which take the name of Cirro-Cumulus. This 

 cloud is often seen alone in the higher regions ; it then 

 assumes a dappled appearance, or what is popularly 

 called a mackerel-back sky. Coloured Corona have their 

 origin in this cloud. 



The Cumulus cloud is seen chiefly in the spring and 

 summer months. Its form, when viewed sideways, in- 

 creases from above in dense, convex heaps ; in showery 

 weather it is tufted with the Cirro- Stratus, and in the 

 interval of the showers its texture is fleecy and its form 

 changes rapidly. In hot weather it often appears sta- 

 tionary with a flattened base, its rock-like summits 

 shining with a silvery light. If during a fine morning 

 this cloud suddenly disappear, and it be followed by the 

 Cirro-Stratus cloud with the wind backing to the south, 

 the mercury falls, and rain soon follows. 



The Cumulus is the day cloud: its great density 

 keeps off the too scorching rays of the noonday sun ; it 

 usually evaporates an hour or two before sunset. When 

 it increases after sunset, and shines with a ruddy cop- 



