27 



the mercury rises, and there is a probability of fine 

 weather. 



It never hails in calm weather. When hail falls, it is 

 during sudden gusts of wind, and the mercury rises 

 while the hail is actually falling. 



If the weather during harvest-time has been generally 

 fine, and a fall of the mercury with a shower occur, if 

 the wind turn a few points to the north and the baro- 

 meter rises above 30 inches, the weather may be ex- 

 pected to be fair for some days. 



When there is only one current of air subsisting in 

 the atmosphere, there is seldom much variation in the 

 height of the mercurial column. It is when two or 

 more strata of the air are in motion in different direc- 

 tions at the same time, that great fluctuations of the 

 mercury occur. 



In high pressures, the upper current usually sets from 

 the northward ; in low pressures it sets from the south 

 and south-west. 



The variations of the barometer are always greater in 

 the winter than in the summer. 



Of the Clouds. 



Howard's Nomenclature. 



Cirrus. Cumulo-Stratus. 



Cirro-Stratus. Stratus. 

 Cirro-Cumulus. Nimbus. 

 Cumulus. Scud. 



c 2 



