Heat 93 



^ 



into a gas holder from which it is conducted by pipes to the place 

 where it is to be used. It burns with a white light, said to be a 

 near approach to sunlight. 



How Heat Is Measured. The amount of heat required to 

 raise the temperature of matter, such as water or other material, 

 may be measured. Just as the gallon is used as the unit in 

 measuring quantities of water, or the bushel in measuring grain, 

 there is a unit of measure for measuring heat. This unit is 

 called the calorie from the Latin word calor, meaning heat. A 

 calorie represents the amount of heat necessary to raise the tem- 

 perature of one gram of water one degree centigrade. It is used 

 in scientific work and in measuring the amount of heat given 

 off in burning various substances. In measuring the heat values 

 of foods and fuels, however, the large Calorie (C) is used. This 

 is 1,000 times larger than the small calorie (c). 



Here is a table which shows the approximate heat values of 

 certain fuels : 



Calories (C) per Pound 

 of Fuel 



Carbon 3672 



Hydrogen 15664 



Various kinds of wood 2141 to 2300 



Charcoal 3227 



Peat 1800 to 2300 



Soft coal 3000 to 3600 



Hard coal 3400 to 3900 



Coke 3450 to 3700 



Petroleum around 5000 



Conservation of Fuel. Nature has been so liberal in the 

 production of fuel material that man has seemed to think it will 

 always last. Accordingly he has mined coal in a wasteful man- 

 ner, allowed natural gas to burn needlessly, and destroyed the 

 forests for commercial purposes without replacing them with new 

 growths, called reforestation. Now that scientists estimate that 

 the available coal supply will be exhausted in the course of 

 about one hundred years, that oil wells are exhausting the oil 

 supply, and that reforestation is not as extensive as is necessary 

 to provide for future use, it would seem that all persons should 

 conserve fuel as much as possible. 



