Basic Pipe Shape Components
You can see the bowl shape by looking at the pipe from the side (in profile, so to speak). However, the bowl shape is even easier to see if you look at the pipe with the stem pointed away from you.
It may sound unromantic, but pipe bowl shape is best understood by referring to geometry. I know what you are thinking--you thought this would be fun, and now you have to relive the eighth grade. Well, we aren't going to bisect any angles or anything like that, so those of you who hated geometry can stop throwing spit-wads at your computer screens. I thank those of you who went to get compasses and protractors for your kind thoughts, but we won't need them either.
Actually, all we need at first is to remember elipses. You know, ovals (like your kid draws all the time in your computer graphics program). Most pipe bowls have shapes that are pieces of elipses (I know I could just say "ovals," but I like the word "elipses"--it makes me feel smart). Just between you and me, let's call these bowls the eliptical bowl shapes. Below are the common ones, and their common names.
A. Dublin-A half-elipse (parabola) bowl
B. billiard-A bowl which is two-thirds of a tall elipse; possibly the most common bowl shape, the name probably comes from the French word for "log."
C. egg-A bowl that is three-quarters of a tall, narrow elipse
D. apple-A bowl that is three-quarters of an elipse that is slightly taller than it is wide
E. prince, author- some pipes of these shapes have bowls that are three-quarters of an elipse that is slightly wider than it is tall.
Not all pipe bowls described by the names above are perfect elipses, of course. It's just that thinking of them as being variations of eliptical sections may help you tell one shape from another. In addition to the bowls at are more or less eliptical, there are a few shapes that don't seem eliptical at all at first, but are in a sense. Some pipe bowls are like fun-house mirror distortions of the elipse, with various parts stretched one way or another. For example:
F. brandyglass- an egg or billiard with flattened bottom and elongated top. Resembles a brandy snifter or wine glass.
G. another variation of the prince bowl, resembling an apple with flattened bottom
H. the pear or acorn bowl, an apple with a flattened rounded top
Some bowls have other shapes that are not based on elipses. These may actually be easier to identify:
I. poker-a cylindrical bowl with (roughly) parallel sides.
J. pot- round-bottomed cylinder (almost parallel sides and flat top). Often width exceeds height.
K. bulldog-diamond shaped in profile; upper portion of the bowl is angular, while the bottom portion of the bowl is similar to a Dublin. This bowl shape is so named because of its similarity to the shape of the dog breed's head.