One Hen, Two Ducks, Three Squawking Geese, Four Limerick Oysters, Five Corpulent Porpoises, Six Pairs of Don Alvarzo's Tweezers, Seven Thousand Macedonians In Full Battle Array, Eight Brass Monkeys From The Ancient Sacred Crypts of Egypt, Nine Apathetic, Sympathetic, Diabetic, Old Men On Roller Skates With A Marked Propensity Towards Procrastination & Sloth.....
Exploding Flame
Action:
From a rubber tube connected to the natural gas outlet you run gas into a hole on the top of the cover of a one-gallon syrup can. After three minutes the can will be filled with gas and you withdraw the tube. You light the gas as it escapes from the hole in the top of the can. The flame at first burns three or four inches high and then gradually subsides and seems to disappear after five minutes. fifteen minutes later an explosion throws the cover into the air.
Why:
Explosions in combustible gases occur in air only when the ration of gas to air reaches a critical value.
You Need:
one-gallon syrup or similar can with friction top cover with a hole 1/8" diam. in the center of the cover and in the center of the base
natural gas source
Suggestions:
The explosion is not violent and therefore not dangerous. The experiment is a good one for a magic show since the explosion is unexpected after a lapse of fifteen minutes between the time that the flame disappears and the moment of the explosion.
Page 74 & 75xx of Chemical Magic, second edition, by Leonard A. Ford. Revised by E. Winston Grundmeier and published by Dover Publications, Inc., New York, # 0-486-67628-5.