There are many types of sundials, but before you are introduced to some of them, you need to know some basic terminology. The first term you need to know is gnomon. A gnomon is a rod or triangular piece of wood or metal on a sundial. The other term you need to know is the north and south celestial poles. The north and south celestial poles are imaginary points in the sky directly above the geographic north and south poles. Now that you know some basic terms, you can learn about some commonly known types of sundials.

 The first and oldest type of sundial is the noon mark sundial. The noon mark sundial marks out the sequence of the noons. Back in the old days, the noon mark sundial was used to signify certain events such as religious ceremonies, and even when it was time for dinner. The noon mark sundial is also the simplest type of sundial known to mankind. The noon mark sundial will only show the same type as your clock on four days of the year. It also almost never shows high noon when the sun is really at it�s highest point in the sky. That�s not very accurate is it? Not at all!

 Another commonly known type of sundial is the horizontal dial. This type of sundial is commonly found in gardens on a post, or engraved in pavement. One way to tell this type of sundial from others is that the gnomon (see, you do need to know those terms at the beginning!) angle is equal to the line of latitude where it is located. The horizontal sundial uses the position of the edge of a gnomon aligned with the North / South Celestial Pole to tell time. These types are harder to make than the vertical direct sundials.

 The most common type of sundial found on houses and churches is the vertical direct sundial. They are located on the walls of buildings. The vertical direct sundials face directly north if they are in the northern hemisphere, and if they are located in the southern hemisphere, they face directly south. The vertical direct sundials are different from other types of sundials because they never show the noon hour. Also, the gnome is positioned at the six o�clock hour of the sundial.

 That�s all about SOME types of common sundial that I think you need to know. If you want to know more, go to another site!