Used to demonstrate the formation of clouds. Rubber bulb is partially filled with water then compressed to force air from the flask. Flask is then filled with smoke by holding the open tube near a smoking match and releasing bulb. After closing the tubing clamp, a cloud can be formed in the flask by compressing and suddenly releasing the bulb. This procedure can be done repeatedly without adding more smoke. Consists of glass flask, a rubber bulb, a spring clamp, and a piece of rubber tubing.