Snow Crystals. 283 



crystals will be observed : colder than this, the deposit will 

 only be as icy spicules, or needles of ice. 



Until the scientific balloon experiments, it was generally 

 thought that the snow crawled along the ground, whilst the 

 hail was formed at a considerable altitude. As a contradiction 

 to this, Mr. Glaisher has passed through snow-storms a mile 

 above the earth. In winter, whilst in mountainous districts, 

 snow-storms may be seen travelling amongst the valleys, with- 

 out ascending the mountains ; and although the mountains are 

 more frequently covered than the valleys, it usually happens, 

 from this circumstance, that whilst rain falls in the valley, the 

 colder hills are receiving it in the form of snow. 



It may be that the snow in winter is very close to the 

 ground, ascending higher into the air the warmer the weather 

 becomes. 



