First the quick break down of a Bong.
The Chamber, Catches and channels the smoke and also holds the water.
The mouthpiece hole,
the mouth goes here, and you breathe in.
Carb or Clutch hole an Air Inlet
To flush the smoke down the mouth.
Downstem bowl or socket pipe,
The Main inlet Pipe to direct smoke into the chamber and also holds the Bowl, it holds the bud while it gets burnt and erases smoke
The base keeps it upright,
You got to add some water and that Equals a bong.
Now for How A Bong Works?
(2)The clutch hole covered,
(3)flame on the Bud Bowl, Breathing in Creates a vacuum within the chamber, The vacuum then displaces the water.
this creates a second vacuum in the downstem that sucks the flame into the Bud Bowl, Burning the bud, and pulling the smoke downwards.
The Constant upward vacuum and the force of gravity both cause the water to act like a liquid diaphragm.
This pulls smoke into the chamber repeatedly to relieve the constant vacuum pressure.
Breathing In keeps the vacuum and diaphragm working to fill the chamber with smoke. as the bud hits it's finished, The Carb hole is opened letting air rush into the chamber, this flushes the smoke quickly into the lungs.
the water catches leftover ash and embers, and also acts as a semi smoke filter.
the bottom of the down steam must be submerged in water, without water a bong is just a fancy dry pipe.