HEAT AND CHANGE OF STATE 61 



with the heat required to raise the same amount of water one 

 degree is called its specific heat. Specific heat is like specific 

 gravity in that water is taken as a standard for comparison. 



TABLE OF BOILING POINTS IN CENTIGRADE DEGREES 



TABLE OP SPECIFIC HEATS 



Alcohol 60 Iron , 12 



Aluminum . : 22 Mercury 033 



Copper 094 Water 1.00 



Ice 50 Zinc 093 



TABLE OF MELTING POINTS IN CENTIGRADE DEGREES 



Alcohol -130 Iron 1530 



Aluminum 658 Mercury 39 



Brass 910 Silver 961 



Copper 1083 Tin 232 



Gold 1063 Zinc 419 



With the exception of hydrogen, water has the highest specific 

 heat of any known substance. It is this quality that makes 

 water so valuable in steam and hot water heating, hot- water 

 bags, and the like. The large amount of heat needed to raise 

 it to the boiling point must all be given out before it can re- 

 sume its original temperature. The high specific heat of 

 water also has an important effect on the daily temperature. 

 The moisture in the air, by warming and cooling slowly, pre- 

 vents sudden or rapid changes in temperature. This also ex- 

 plains the mild climate of regions near large bodies of water. 

 In summer they are cooler than places further inland because 

 much of the heat goes to warm the water, and in winter they 

 are warmer because the heat taken up by the water is now 



