If you’re looking to make a simple vortex canon for shooting smoke rings across the room, you’ll like this DIY video by Dave Hax. All you’ll need is an empty plastic bottle, a balloon, and an incense stick, preferably of a scent that you like. Now watch How to make smoke rings, above, to put it all together.
As always, kiddos, be safe, smart, and keep an adult around when conducting fire-related experiments, and note: Glowing or smoking end of an incense stick is still hot and can burn skin or surfaces, even when there’s no flame.
Want more of a challenge? Make a larger vortex cannon.