Democracy, theater, olive oil, and other bedrocks of Western civilization all got their start with the Greeks. But even some things that might seem like squarely modern inventions have Hellenistic roots, including the humble vending machine.

In the first century CE, Greek engineer and mathematician Heron of Alexandria published a two-volume treatise on mechanics called Pneumatica. Within its pages were an assortment of mechanical devices capable of all types of wonders: a never-ending wine cup, rudimentary automatic doors, singing mechanical birds, various automata, the world’s first steam engine, and a coin-operated vending machine. 

Heron’s invention wasn’t made with Funyuns and Coca-Cola in mind, however: It dispensed holy water. In Heron’s time, Alexandria was a province of the Greek empire and home to a cornucopia of religions with Roman, Greek, and Egyptian influences.

To stand out, many temples hired Heron to supply mechanical miracles meant to encourage faith in believers. Some of these temples also had holy water, and experts believe Heron’s vending machine was invented to moderate acolytes who took too much of it.

The mechanism was simple enough: When a coin was inserted in the machine, it weighed down a balancing arm, which in turn pulled a string opening a plug on a container of liquid. Once the coin dropped off the arm, the liquid stopped flowing. It would be another 1,800 years before modern vending machines began to take shape — many of them using the same principles as Heron’s miraculous holy water dispenser.

And the miracles are just as effective.