BAROMETER. 321 



drop, except EASTERN winds : those winds 

 which blow from the SOUTH, and SOUTH- 

 WEST make it drop the lowest. 



Q. W hy do WINDS generally make the mercury 

 of a barometer DROP ? 



A. Wind is caused by a partial 

 vacuum in some parts of the globe j and 

 as the air rushes in to supply this 

 deficiency, its general pressure is lessened, 

 and the barometer falls. 



Q. Wliat is the SRD SPECIAL RULE in regard 

 to the barometer ? 



A. While the barometer stands above 

 30, the air must be very dry or very 

 cold, or perhaps both, and no rain may be 

 expected. 



Q. Why will there $e NO RAIN if the AIR be 

 very DRY ? 



A. If the air be very dry it will 

 absorb moisture, and not part with what 

 it has in rain. 



Q. Why will there be NO RAIN if the AIR 

 be very COLD ? 



A. If the air be very cold it is so 

 much condensed, that it has already 

 parted with as much moisture as it can 

 spare. 



