GASOLINE AND KEROSENE STOVES 213 



there is great waste of fuel; for only the top of the stove 

 is heated. But the cook stove has a "back damper " 

 which compels these gases to travel in a roundabout way, 

 heating a large surface of the oven before they enter the 

 pipe leading to the chimney. Wood and coal stoves have 

 a slightly different construction. 



240. Gas Stoves. Gas stoves are rapidly taking the 

 place of wood and coal stoves, wherever gas can be ob- 

 tained. The gas used for lighting has a smoky flame, 

 and deposits soot. To avoid the soot, and to secure a 

 hot flame, we use the principle of the Bunsen 



burner (Fig. 202). In this burner the gas 

 escapes through a pin-hole into a mixing tube. 

 The tube has air holes near the gas inlet. The 

 small, rapid current of gas draws the air into 

 these air holes, and the mixture of air and gas _________ 



burns at the top of the burner. The flame is Fig. 202. 

 smaller than if the gas were burned directly; 

 but it is also hotter. Since the gas is mixed thoroughly 

 with air, the flame is smokeless. Smoke, or soot, repre- 

 sents wasted fuel. 



If the supply of air taken in by the Bunsen burner is 

 too great for the amount of gas, there is a slight explosion 

 in the mixing tube, and the flame "strikes back" to the 

 narrow opening inside the burner. If we regulate the 

 gas supply and the size of the air holes, this will rarely 

 take place. In gas stoves the air holes are at the front, 

 near the openings through which gas enters. 



241. Gasoline and Kerosene Stoves. The gasoline 

 burner is essentially a Bunsen burner. To light the 



