Erlenmeyer flask (I used 125 mL flasks)
dish to hold water in the base
matches to light the candle
water with food coloring (helps the students see what is happening)
Fill the dish about half way with colored water. Light the candle and put in the center of the three pennies in the shallow dish. Balance the flask upside down on the three pennies in the shallow dish.
After students try the situation the first time, I encourage them to experiment with the situation to test their explanations about what is happening.