PROPERTIES OF GASOLINE 29 



Now place two tablespoonfuls of gasoline in another cup. Take its 

 temperature. Remove the thermometer. Try lighting the gasoline 

 as you did the kerosene. Be sure that the glass is close by so that you 

 can cover the dish quickly in case the oil catches on fire. Also be sure 

 that the can of gasoline has been removed from the room, or tightly corked. 

 When the flame has been extinguished, remove the glass from the 

 dish, light another match and bring it slowly down above the dish- 

 to see at what height above the surface of the gasoline the flash does 

 take place. Try again. Is it the liquid gasoline which burns? 



Set the gasoline to one side, and make a further study of the kero- 

 sene. If you have a good quality of oil, you have probably not yet 

 succeeded in making it burn. Fit the wire 

 gauze on the ring of the stand. Set the cup 

 of kerosene on the gauze and heat very gently 

 (Fig. 15). Test the oil frequently with the 

 lighted match to see if it will catch on fire. 

 When it is hot enough it will suddenly flash 

 when the lighted match is applied. Take its 

 temperature. This temperature is somewhat, 

 perhaps slightly, above the FLASHING POINT. 

 If the flame continues to burn above the sur- , 



. . ., . , . , .. , , riG. lo. riasmng 



face of the oil, you have heated it several degrees point of kerosene, 

 above the flashing point. It is, indeed, above 

 the BURNING POINT. Let the oil cool. But to do so you must put 

 out the flame. Take the temperature each minute or two, as it 

 cools, and after each reading of the thermometer test the oil with a 

 lighted match to see if it still burns. When it no longer burns, you 

 have passed the BURNING POINT. It may still flash, however, but 

 the flame immediately goes out. It is still above the FLASHING 

 POINT if this is the case. When the oil no longer flashes you have 

 passed the flashing point. 



DEFINITIONS. The flashing point of an oil is the, lowest 

 temperature of that oil at which it will give off enough vapor so 

 that when mixed with the air above, it produces a momentary 

 flash when a flame is brought near the surface of the oil. 



The burning point, or fire test, of an oil is the lowest temperature 

 of that oil at which it will give off enough vapor to maintain a 

 continuous flame when once ignited. 



The burning point of kerosene may be from 20 to 60F. 

 higher than its flashing point. In ordinary kerosene it is 

 usually from 40 to 50F. higher. Most of the states have 



