EXPANSION. 105 



Q. Why does the ESCAPE OF AIR from the 

 chestnut, or the EXPLOSION of GUNPOWDER, produce 

 a REPORT? 



A. Because a quantity of air (sud- 

 denly let loose) pushes against the air 

 around, in order to make room for itself ; 

 and as the air of the chestnut slaps against 

 the air of the room, a report is made, (as 

 when I slap a book or table). 



Q. If a CHESTNUT be SLIT, it will NOT CRACK ; 

 why is this P 



A. Because the heated air of the 

 chestnut can freely escape through the 

 slit in the rind. 



Q. Why does an APPLE spit and SPUBT about, 

 when roasted ? 



A. An apple contains a vast quantity 

 of air, which (being expanded by the 

 heat of the fire) bursts through the peel, 

 carrying the juice of the apple along 

 with it. 



Q. Does an APPLE contain MORE AIR, in 

 proportion, than a CHESTNUT? 



A. Yes, much more. There is as 

 much condensed air in a common apple, 

 as would fill a space 48 times as big as 

 the apple itself'. 



