The compass in its most fundamental form consists simply of a magnetic needle with a colored tip to indicate north, mounted on a pivot at the center of a compass card marked with the cardinal directions – N, S, E, W. Quadrants are normally subdivided, either by degrees or marked with lines to indicate NW, NE, SE, and SW. Wood-clad compasses are among the oldest designs, and pocket compasses one of the most common during the 18th and 19th Centuries. Pocket compasses are usually design like pocket watches with a hinged lid or a cover cap.