THE REASON WHY. 47 



" The fining pot is for silver, and the furnace for gold : but the Lord trieth the 

 hearts." PKO VERBS xvn. 



121. Which feels the warmer, the conductor or non-con- 

 ductor ? 



The non-conductor, as it does not readily absorb the warmth of 

 our bodies. 



122. What substances are the lest conductors ofheat? 



Gold, silver, copper, and most substances of close and hard for- 

 mation, &c. 



123. What substances are the worst conductors ofheat? 

 Fur, eider down, feathers, raw silk, wood, lamp-black, cotton, 



soot, charcoal, &c. 



124. Why has the toasting-fork a wooden handle ? 



Because wood is not so good a conductor as metal, therefore the 

 wood prevents the heat from being transmitted by conduction to 

 our hands. 



125. Why lias the coffee-pot a wooden "handle ? 



Because the metal of the coffee-pot would otherwise conduct the 

 heat to the hand ; but wood, being a bad conductor, prevents it. 



126. Why does hot water in a metal jug feel hotter than 

 in an earthenware one ? 



Because metal, being a good conductor, readily delivers heat to 

 the hand ; but earthenware, being an indifferent conductor, parts 

 with the heat slowly. -, 



127. How can ive ascertain that ivood prevents the conduc- 

 tion ofheat to the hand? 



By passing the top of the finger along the wooden handle of the 

 coffee-pot, until it raaches the point where the wood meets the 

 metal. The wooden handle will be found to be cool, but the metal 

 will feel very hot, 



128. Of what use are kettle-holders ? 



Being made of bad conductors, such as wood, paper, or 

 woollen cloth, they will not readily conduct the heat from the kettlo 

 to the hand. 



