About two weeks ago, I posted photos and a description of a puzzling device on Facebook, and offered anyone the chance to guess how it worked. Here's the original problem (edited for clarity), with the explanation after the jump.
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This beautiful coffee engine (circa 1850) came into the shop today for repairs. The owner didn't know how it worked or if it ever had, so I had the pleasure of tinkering around with it to determine the mechanism. Anyone want to see if they can guess how it works?
Some important details: There are two chambers that liquid can go in. The front chamber (Left, towards tap) is completely closed off except for the chimney, and does not seal. It does not directly connect to the other chamber, nor the tap. The rear chamber has (left to right) a tight connection to the U- shaped tube spout, a stoppered funnel to pour water into, and a whistle with a valve that closes.
The u- shaped tube spout is open all the way through, and ends with a perforated strainer. The strainer does not open like a tea ball.
The engine ensemble (both front and rear compartments) balance on the carriage in such a way that it may rock back and forth slightly, though the rear is much heavier. Below the carriage is a spirit lamp with a hinged lid, and when the engine rocks forward it pops a small lever to flip the lid closed.
There is a small box on level with the engine, probably for holding dry tea/coffee grounds. It is not involved in the mechanism.
Done guessing? Follow the jump!
