gooutat all, if the corks were very large. In the glass chimneys,neitherflame
went out,butthe flame inside the chimney resting on corks wasstrongerand
brighter.
Theunionofoxygen from the air with aburningfuelproducesflame. Since
fire results from oxidation,it obviouslycannotoccurwithoutoxygen. No air
could enter the glasses covering candles Nos. Iand3. They went out assoon
as they used up the oxygen that wasalreadyin the air inside the glasses. The
glass over candle No. 3 was larger and containedmore air to begin with, so
candle No. 3burneda little longer. A little airenteredthe glasses covering
candles Nos. 2 and 4throughthe opening made by the corks between the glasses
and the table.Therefore,theycontinuedto burn.The candlesunderthe glass
chimneys alsocontinuedtoburn,because airenteredfrom above.CandleNo.6,
however,burnedmore strongly, because ithada supplyofairbothfrom above
andbelow.
NOTE:experiments marked with an asterisk(*)are potentially dangerous.
Parentsshould decide how much supervision is necessary.HOWYOU CAN MAKEAFUEL*
Gather these materials:An alcohol burnerand a"fishtailtip";anupright
standandclamp;I pyrex testtube;one 8-inch lengthofglasstubing;a triangu-
lar file; al-holedstopper;some lumpsofcoal;a piepan;papertowels; and a
hammer.
Follow this procedure:Place the fishtail tip on the alcoholburnerand light it.
Rotatethe glasstubingin the flame by holding each end, as you learned on page- When the flame becomes brightorangeand when the glass is soft, pull the
endsapartquickly. Allow the glass to cool.CAUTION:Rememberthathotglass