Take the rather short stearic candle and a glass of water. The lower end of the candle weighing hot nail (if the nail will be cold, then the candle crumble) so that only the very edge of the wick and the candle remained above the surface.
A glass of water, which floats, this candle will be a candlestick. Light the wick and the candle will burn for a long time. It seems that she is about to burn down to the water and the light goes out. But this will not happen. The candle will burn down almost to the end. And besides, a candle in a candlestick will never cause a fire. The wick is extinguished with water.