An Erlenmeyer flask with a little water in it is heated over a flame, until steam visibly rises out of the copper pipe connected to the flask. The spiral copper pipe is then intensely heated with a blowtorch, until the steam is no longer visible. An unlit match is held in front of the pipe opening, and it ignites.
How does it work?
When the steam flows through the spiral tube, it becomes strongly heated, so that it is closer to 300°C rather than 100°C. At this temperature the steam is hot enough to heat the match, so it can light itself.