124 



FUELS 





great a boon oil is to persons living in regions cut off from 

 these advantages. In many places oil is used entirely for 

 cooking, because wood is reserved for lumber, or because coal 

 is too expensive to transport, or because gas is not manu- 

 factured. 



Gas and oil are not economical for house heating, but they are 

 economical for cooking, especially in summer, when the heat for 

 cooking is needed only at intervals. A coal fire burns in the 

 range all day, and even if the fire is kept low except when food 

 is being cooked, a considerable amount of coal is consumed. 

 In oil and gas stoves, fuel is burned only while the food is ac- 

 tually cooking. But in winter, when fuel 

 is used for warming the house as well as 

 for cooking the food, coal is the most eco- 

 nomical fuel. The heat given out by or- 

 dinary gas and oil stoves is not sufficient to 

 warm a house, but in houses which are 

 poorly heated by coal stoves or furnaces, 

 oil is frequently used to supplement the 

 coal stoves. An oil stove such as is seen 

 in Figure 50 is intended for supplementary 

 house heating. An oil stove of this type 

 may have a different top and be very use- 

 ful for cooking. 



Kerosene or coal oils. The oils most 

 widely used for cooking are kerosene and 

 gasoline. Both of these are obtained from 

 the thick dark petroleum which occurs 

 as an underground liquid in California, Oklahoma, Texas, 

 Pennsylvania, and some other states. 



Crude petroleum, or petroleum just as it comes from the 

 earth, may be used as fuel, and is frequently so used on steam- 

 ships and locomotives. Usually, however, it is refined or dis- 



FIG. 50. Oil stove for 

 heating. 



