In this activity: gravity; water pressure; air pressure; hydraulics; ancient technology
This week, my aspiring engineers constructed a simple fountain powered by gravity, air pressure, and water pressure! The concept behind this invention comes from Heron of Alexandria, a first century mathematician and physicist. While Heron’s fountain is usually built using two air-tight containers, the version we tried was inspired by Kayla from Choose Joy Homeschool. It was somewhat more kid-friendly than the classic version, and it allowed us to keep our containers intact so we can re-use them for future projects!
Try it yourself! Our materials:
- 2 LARGE bottles (We used Gatorade bottles, but you could use 2-liter soda bottles or something as large as 5-gallon water bottles.
- 1 Mason jar with lid and canning ring (Our jar was a quart-size, and we chose it for it’s squarish shape — those nice flat sides make it easy to see the water inside.)
- rubber tubing (such as you find at the pet store for aquariums)
- 1 rigid plastic tube or straw
- electrical tape
- 1 waterproof carton (Thin plastic would work for this, but we used the waxed cardboard from a half and half carton because we could easily cut it with scissors and make holes with a hole punch.)
- a box or crate to hold up your water supply (The success of this apparatus relies on the height difference between your water supply and your drainage reservoir.)
- 1 or more enthusiastic children
Use the lid of the Mason jar to trace a circle on your cardboard carton. Cut it out and punch two holes in it — one for the fountain faucet and one for the drain. Place the circle inside the metal canning ring. It should fit snugly. Thread a length of rubber tubing through your straw to create a faucet, and attach your faucet and drain tubing through the holes as shown below. Use electrical tape to secure your pipes and seal out any air. Make the tube leading to your faucet long enough to reach the bottom of your supply container and the drain tube long enough to fit comfortably into your reservoir. We secured the drain pipe into the jar lid before trimming it to about 1/2 inch.
Prime your fountain by filling the jar about 1/4 full of water. Secure the lid, place the drain pipe into your reservoir, then flip your jar and place the faucet pipe into your water supply. With these large water containers and the narrow diameter of our rubber tubing, our fountain can run for about twenty minutes before needing to be refilled!