Discover and experience the principle of steam power in a model-like way. The Knatter-, Putt-Putt- or Puff-Paff-Boat is a toy boat with water impulse propulsion (steam jet propulsion, pulse motor, pulsed waterjet). The simple engine operates without moving parts such as pistons, valves, or wheels. A candle or another heat source serves as the energy source. Fill water into one of the two pipes at the end of the boat until it flows out of the other pipe. Now carefully place the boat on the water. Position the flame in the boat under the boiler. The journey begins after a few moments.