V. Classification and Symbolization 1. An example of ordinal point symbols, for instance, are city labels that vary in type size according to ranges of population. Point Line Area Nominal . . . Most topographic maps have two kinds of contour lines to indicate elevation. Major, or index, contours occur about every fourth or fifth contour with a darker tone.
Minor contours show elevation between index contours.
Jacksonville Beach, FL . . . Altoona, PA . . . Gilroy Hot Springs, CA . . . Santa Rosa, CA . . . Use the chart on the accompanying page.