BASE PLATE: The flat part of the compass; the magnifying lens, map scales, direction of travel arrow, and a hole for the neck cord are in this part.
HOUSING: The round dial that turns; has orienting lines, orienting arrow, North point, magnetic needle, and is graduated to 360° in 2° increments.
TRUE NORTH: Actual direction of the North Pole.
GRID NORTH: The vertical grid lines (Meridians) on a topographical map.
MAGNETIC NORTH: The direction toward which the magnetic needle points (somewhere north of Hudson Bay in Canada).
MAGNETIC VARIATION: The angle between true north and magnetic north (here it is 17 ˝ degrees East).
GRID OR MAP BEARING: “Map-to-terrain” bearings.
FIELD BEARING: Magnetic or compass bearing; “terrain to map.”
“SETTING” THE MAP: Turning the map so that North is North.
BACK BEARING: Shooting back to the landmark to see if you are still on the line--turn you and your compass around; point the direction of travel arrow at the landmark; with the bearing degree set, the “south” arrow will be in the North lane if you are still on line.
CARDINAL AND INTERCARDINAL COMPASS POINTS: