Teach a variety of physical science concepts with the simplest steam engine. Add water to the flask, insert the rubber stopper with exhaust arms, and hang it securely. Then, use a Bunsen burner to heat the water and watch the engine spin! Illustrates important physical principles such as phase changes, pressure, conservation of momentum, and Newton's third law of motion-for every action there is an equal and opposite reaction. This demonstration is a real crowd-pleaser. Complete instructions are provided.