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The "burning candle" experiment is used in middle school education programs to prove that air contains a component that is essential to burning (i.e., oxygen). The accepted interpretation taught by teachers in middle school is this: when burning occurs, oxygen is used up, creating an underpressure that causes a rise in water level inside the covering vessel. The history of the physics and chemistry of the burning candle experiment may be found in the rewritten lectures of Faraday (Faraday, 1978). This paper describes the theoretical considerations on which the experiment is based. It describes the experiment as it was conducted with a class of students to provide a basis for a new, fuller description of what actually happens in this experiment. This study also introduces the concept of students using a video camera in the observation and documentation process as part of the teaching and learning process.

We consider a demonstration in which pupils alternately slide and stop their fingers under a long horizontal rod which they support. The changeover is described in terms of the relevant kinetic and static friction. We present a model calculation, performed on a spreadsheet, which clarifies the process and describes graphically the stepwise switches as the fingers approach the centre of mass of the rod. (Contains 6 figures.)