SNOW AND HAIL 143 



References : 



1. 1103:129-137. Formation of Fog and Clouds. Classifi- 



cation of Clouds. 



2. 1304:247-248. Fog and Clouds. 



3. Weather Bureau. Classification of Clouds. With Chart, 

 a. 1102 : 158-159. Fog and the Cause of Condensation. 

 6. 1301 : 133-140. Fog and Clouds. 



c. 1303 : 62-64. Clouds, Fogs, and Mist. 



d. 1305:68-70. Fog and Clouds. 



e. 1306:169-174. Fog and Clouds. 



/. 1307 : 235-238. Clouds and their Nomenclature. 



g. 1311 : 228-231. Fog and Clouds. 



h. 1309 : 242-247. Fog and Clouds. 



i. 1310 : 367-373. Cloud, Dew, and Frost. 



j. 1312:382-385. Clouds. 



105. SNOW AND HAIL 



Snow is not frozen rain, but may be considered as aerial 

 frost. Snow is formed where water vapor is cooled so sud- 

 denly that it passes directly from the vapor state into the 

 solid state, without any intermediate liquid state. That is, 

 the formation of snow is an example of sublimation. Snow 

 crystals are very beautiful and are of many varieties, although 

 all are six-sided, or six-spoked, at angles of 60. 



Hail is frozen rain. The formation of the larger hailstones 

 requires quite a long period of time and many ascents and 

 descents before they finally fall to the ground. The rain 

 falls through a layer of cold air and is partly frozen; then 

 other currents of air force the tiny hailstones back into the 

 colder layer of air, where they grow by the addition of more 

 freezing water. This process continues until the ascending 

 currents cannot sustain the increasing weight of the hailstones, 

 which then fall for the last time. Much damage to windows. 



