This experiment was done thousands of years ago by the Greek scientist Hero using the steam generated by boiling water. We will do it with the gas generated by subliming dry ice. Using a push-pin, poke two holes into opposite sides of a film canister, near the bottom. The holes should be off-center, like pinwheel rockets. Tie a loop of thread, fitting loosely over the cap like the diagram below. Loop it over the cap in a manner such that when you snap the cap onto the canister, you can hold the canister by the remaining length of thread. Place a small piece of dry ice into the can. Then, quickly add some warm water, and close the lid with the thread attached. Lift the can by the thread, and watch what happens! You have created a little pinwheel motor, power by the escaping carbon dioxide gas.