96 MECHANICAL ACTION. 



A. Beating the iron condenses the 

 particles of the metal ; and squeezes out 

 its latent heat, as water from a sponge. 



Q. Does COLD iron contain HEAT ? 



A. Yes ; every thing contains heat ; 

 but when a thing feels cold, its heat is 



LATENT. 



Q. What is meant by LATENT HEAT ? 



A. Heat not perceptible to our feeling. 

 When anything contains heat without 

 feeling the hotter for it, that heat is called 

 "latent." (Seep. 31.) 



Q. Does COLD iron contain latent HEAT ? 



A. Yes; and when a blacksmith 

 compresses the particles of the iron by 

 his hammer, he squeezes out this latent 

 heat, and makes the iron red-hot. 



Q. How did blacksmiths use to LIGHT THEIR 

 MATCHES before the general use of lucifers ? 



A. They used to place a soft iron 

 nail upon their anvil ; strike it two or 

 three times with a hammer ; and the 

 point became sufficiently hot to light a 

 brimstone match. 



Q. How can a NAIL (beaten by a hammer) 

 IGNITE a brimstone MATCH ? 



