Our main interest in the dragon was to have it blow flames or smoke. Fire was ruled out due to safety issues so we decided to simulate smoke, the most difficult aspect of building our dragon. First we considered making him blow bubbles or a puff of baby powder, but then, for a more authentic effect, decided to try dry ice or liquid nitrogen. We decided to use liquid nitrogen because it produced more smoke than dry ice when water was added to it. Our next problem, however, was determining how to drop the water into the liquid nitrogen when prompted. We tried making a pipe-like mechanism, having water flow through a straw into the cup of liquid nitrogen. However, making a device using a sliding gear rack to stop and start the flow of water in the straw was not effective. The straw was too hard to pinch and seal off. We realized that just pouring water by some means into the liquid nitrogen would be more effective, but we had trouble finding a container that worked well for pouring. We tried a plastic condiment cup and a balloon-like dropper without success and so ended up with the cap of Dove body wash. It was the perfect shape to be tipped and to dispense water: slightly elongated and cradle-like. The liquid nitrogen is contained in three styrofoam cups, each one placed inside the other. The plastic lid of a Starbuck’s insulated cup serves as a lid for the liquid nitrogen. A piece of tubing runs from a hole in the lid upward to the dragon’s mouth.
***Many thanks to Harry Clark and the Chemistry and Biology Departments for providing practically all of the materials needed to produce smoke!***