THE KEROSENE LAMP 5 



Exercise 3. Shutting the Fresh Air Away from the Candle 



Light a piece of candle 1 or 2 in. in length and stand it on the table 

 before you. Watch it for a minute to see that it burns properly. 

 Xow invert a tumbler and place it over the candle. Does the candle 

 continue to burn? Remove the tumbler. Re -light the candle. 

 Try the experiment again, using a 2-qt. fruit jar instead of the 

 tumbler. Does the candle continue to burn longer this time ? Why ? 

 Re-light the candle. Again place the fruit jar over the 

 burning candle. Watch carefully to see what happens 

 just as the flame goes out. Is there much smoke given 

 off for a moment after the flame dies out? What is this 

 smoke? If it is paraffin vapor, why does it not burn? 

 (Fig. 5.) FIG. s._ Ex- 



No w carefully raise the jar and set it aside while you eluding fresh 

 re-light the candle, letting just as little fresh air into ^ r jjj om the 

 it as possible. Again place the jar over the candle and 

 notice carefully how long the flame continues this tune. Raise the 

 jar, blow all the smoke out of it; re-light the candle and again place 

 the jar over the candle. Does the flame burn longer than it did 

 before? Explain. 



EXPLANATION. As long as the wick is hot there will be 

 plenty of paraffin vapor. But this vapor cannot possibly 

 burn alone. The flame is the result of the uniting of the vapor 

 with one of the gases, OXYGEN, in the fresh air. The air is not 

 fresh when the vapor has burned out the oxygen. No matter 

 how much of the burned air and vapor you may have in the tumbler, 

 or how well mixed they may be, you can not get a flame till you 

 have some of the fresh, unburnt air mixed with the vapor. 



II. THE KEROSENE LAMP 



7. The First Kerosene Lamp. The kerosene lamp has been 

 in use only about 50 years. The lamps which had previously 

 been used usually burned heavy oils and fats, which gave only 

 low, flickering, smoky flames. During the first half of the last 

 century WHALE OIL was in common use along the seacoast. 

 Whale oil lamps were less smoky and disagreeable than most 

 lamps of the period. A few lamps had been made which burned 

 so-called BURNING FLUIDS. But these fluids were very inflam- 



