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Tobacco Smoking Culture:

Structure and Operation of Hookah Pipes

Excluding grommets, a hookah is usually made of five components, four of which are essential for its operation.

The bowl
Also known as the head of the hookah, the bowl is a container, usually made out of clay or marble, that holds the coal and tobacco during the smoking session. The bowl is loaded with tobacco then covered in a small piece of perforated tin foil or a metal screen. Lit coals are then placed on top, which allows the tobacco to heat to the proper temperature.

Hose
The hose is a slender tube that allows the smoke to be drawn. The end is typically fitted with a metal, wooden, or plastic mouthpiece.

Body, Gasket, Valve
The body of the hookah is a hollow tube with a gasket at its bottom. The gasket itself has at least one opening for the hose. The gasket seals the connection of the body of the hookah with the water jar. The gasket may have an additional opening with a valve for clearing the smoke from the water jar rather than through the hose. In some cases the gasket may contain openings for more than one hose.

Water jar
Placed at the bottom of the hookah, the water jar is a container through which the smoke from the tobacco passes before it reaches the hose. By passing through water, the smoke gains moisture and is lowered in temperature. The level of the water has to be higher than the lowest point of the body's tube in order for the smoke to pass through it. Liquids other than water may be used, such as alcohol, spirit and/or fruit juice, and in many cases, ice may be put in the bottom of the jar to dramatically increase the drop in temperature, making for a smoother smoke.

Plate
The plate (ash tray) is usually just below the bowl and is used for "dead" coals from previous smoking sessions.

Grommets
Grommets in a hookah are usually placed between the bowl and the body, the body's gasket and the water jar and between the body and the hose. The reason for the usage of grommets although not essential (the usage of paper or tape has become common) will help to seal the joints between the parts, therefore decreasing the amount of air coming in and maximizing the smoke breathed in.

Operation
The jar at the bottom of the hookah is filled with water sufficient to submerge a few centimeters of the body tube, which is sealed tightly to it. Tobacco is placed inside the bowl at the top of the hookah and a burning charcoal is placed on top of the tobacco. Some cultures cover the bowl with perforated tin foil to separate the coal and the tobacco, which minimizes inhalation of coal ash with the smoke.

When one inhales via the hose, air is pulled through the coal and into the bowl. The air, hot from the charcoal, roasts the tobacco, producing smoke. This smoke passes down through the body tube, which extends into the water in the jar. It bubbles up through the water and fills the top part of the jar, to which the hose is attached. When a smoker inhales from the hose, smoke passes into the lungs, and the change in pressure in the jar pulls more air through the charcoal, continuing the process.