A siphon pot has two stacked glass globes, and works a little like a macchinetta, that stove-top gadget wrongly called an espresso maker by generations of graduate students. As water vapor forces water into the upper globe the coffee grounds are stirred by hand with a bamboo paddle. (In Japan, siphon coffee masters carve their own paddles to fit the shape of their palms.)
The goal is to create a deep whirlpool in no more than four turns without touching the glass. Posture is important. So is timing: siphon coffee has a brewing cycle of 45 to 90 seconds.