A sundial consists of two parts: the stile, or gnomon, usually the edge of a plate of metal, made parallel to the earth's axis, and pointing toward the pole; and the dial plane, on which are marked the several hours of the day, their halves, quarters, etc. Sundials receive various names, according to the positions they are constructed to occupy. When the sundial is level it is called a horizontal sundial; when perpendicular to that plane, a vertical sundial An equinoctial sundial is one whose plane is parallel to the equator. There are others. the south sundial, north sundial, east sundial, west sundial, polar sundial, and declining sundial.
