Buttons feel magical. You press here, and invisible connections make something happen elsewhere. But “magical” is probably not how I’d describe most public drinking fountains.

Who among us hasn’t walked up to a drinking fountain, expecting a bubbling stream of life-giving water, only to experience the crushing disappointment of a measly trickle after smashing in that button?

But I’m beginning to think it’s not the drinking button’s fault; they’re actually some of the most elegant buttons out there. They’re one of the few remaining buttons where your push directly and mechanically controls the result. They’re over a hundred years old. And all the action happens within an inch of the button itself.

When your thumb pushes that metal disc inward, you’re also pressing a button beneath the button that uncaps a spout inside the spout. There’s a seal inside that blocks the flow of water when the button’s sticking out and releases it when you press down. Pushing down moves the seal that normally covers a tiny waterspout inside the mechanism, letting the water through. Then, it’s free to move, fill up the inside of the faucet, and shoot out the fountain at around 0.4 gallons per minute.

Sounds simple, right? But the genius of the drinking fountain button is that it’s modularly repairable. That whole mechanism is part of a self-contained cartridge that’s easy to remove and swap out.

A quick patent search shows the cartridge idea dates back to at least the late 1950s, and drinking fountain manufacturers have all but standardized on it today. “Three of our four competitors use this same cartridge,” says Bill Epker, a 45-year veteran of Haws Corporation, a company that started building and patenting drinking fountain tech in 1906. Whether you’re looking at a push button, a push bar, or even one of those little silver buttons on top of a faucet head, they’ve almost all got the same cartridge inside, says Epker.

But drinking fountain giant Halsey Taylor at least imagined a push button in its very first patent in 1912. And by 1928, they definitely seem to have caught on: a patent from that year notes that drinking fountains were “usually equipped with push-buttons” to open their valves — just without the cartridge part.

Why the move from levers to buttons? Haws, which actually didn’t switch over until 1984, says maintenance became much easier when cartridge systems came along. Modern ones even have dedicated filters to keep their internals from clogging as quickly, and a screwdriver hole that lets anyone with a small screwdriver adjust the height of the stream — by changing the maximum distance the seal moves away from the internal water port.

They’re harder to vandalize, too, with no lever to break off and a silver (or copper) disc cover that just spins in place if you try to twist it. Yet they’re still easily repairable: Haws patented a version in 2006 that lets a repairperson easily remove the button and access the cartridge with a single special wrench.

But ironically, it’s a lack of even that basic maintenance that turns bubblers into dribblers, Haws technical product manager Josh Linn tells me. Many just need their strainer cleaned out or their height screw adjusted, he says. One of the company’s owners used to carry a little screwdriver around everywhere they went to fix dribbling fountains — if you want to try it yourself, Epker says a 1/8-inch flat-blade screwdriver is the largest that will fit.

Not that you should need to in the US, where a shitty public drinking fountain experience is technically against the law! The Americans with Disabilities Act requires them to shoot a stream of water at least four inches high. Also, controls “shall not require tight grasping, pinching, or twisting of the wrist,” and a fountain can’t take more than five pounds of force from a single hand to operate.

So, before you blame that button, maybe let your local parks department know it needs fixed?

Purely physical drinking fountain buttons may not stick around forever. Some refrigerated indoor water fountains already use microswitches and solenoids to dispense their product, and many water bottle fillers use hands-free sensors instead of buttons. Many people now pick packaged bottled water, too, even though most bottled water in the US is refiltered tap water and is not necessarily cleaner.

But Haws says that at least customers seem to have cooled on buying hands-free sensors for their normal drinking fountains now that the covid-19 pandemic has died down. “I would say people are falling back to mechanical operation more and more,” says marketing manager Mike Wilhelm. “Fewer things can go wrong, it’s easier to maintain over time.”

For now, the button is simply more reliable.