you'll get no potato juice or coffee perpetuum

Over the weekend, we were treated to another demonstration of my parents' very clever vintage balance siphon coffee maker, which I have decided violates the laws of thermodynamics. It's quite a brilliant and entertaining performance, like an ornate fountain or Glockenspiel to toll the hour: a spirit lamp heats up water in the metal chamber and once it reaches a critical temperature, siphons through and infuses the coffee grounds in the glass carafe (bell jar).

Voided of water, the metal piston rises and extinguishes the fire, and as it's cooled, the pressure imbalance forces the brewed coffee back into the canister. It is a heuristic perpetual motion machine, a challenge to find the right grade of ground, right ratio of water to coffee, and the coffee tastes very pure. The whole process is engrossing, having never seen such a configuration or knew a kitchen contraption to operate on such principles, and very steam-punk--much more heroic than the usual delivery method.