what is the imaginary line running north and south
(geographical) meridian line of longitude
title: Fifth principal meridian text: Fifth principal meridian The Fifth principal meridian, often denoted the "5th Meridian" or "PM 05," is a principal meridian survey line used in the United States for land claims in the Public Land Survey System (PLSS). It was first surveyed in 1815. The meridian, a north-south line, starts from the old mouth of the Arkansas River and runs north. Another survey line related to it is the base line running west from the old mouth of the St. Francis River. These survey lines govern all land surveys in four states and a large portion of the land surveys for two title: Contour line text: Contour line A contour line (also isoline, isopleth, or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional graph of the function "f"("x", "y") parallel to the "x", "y" plane. In cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. A contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys title: Mason–Dixon line text: use when the Missouri Compromise named "Mason and Dixon's line" as part of the boundary between slave territory and free territory. In popular usage to people from the Northern United States, the Mason–Dixon line symbolizes a cultural boundary between the North and the South (Dixie). However, for many people who identify as Southern, Maryland is not considered a Southern state, leading to confusion over terminology (for more on Maryland's position as southern or northern, see the Region section of the article on Dixie). Originally "Mason and Dixon's Line" referred to the border between Pennsylvania and Maryland. After Pennsylvania abolished slavery, title: Fifth principal meridian text: the L'Anguille Chapter." Fifth principal meridian The Fifth principal meridian, often denoted the "5th Meridian" or "PM 05," is a principal meridian survey line used in the United States for land claims in the Public Land Survey System (PLSS). It was first surveyed in 1815. The meridian, a north-south line, starts from the old mouth of the Arkansas River and runs north. Another survey line related to it is the base line running west from the old mouth of the St. Francis River. These survey lines govern all land surveys in four states and a large portion of the land title: 104th meridian west text: west of Greenwich roughly defines the eastern extent of the region of high plains protected by the Southern Rocky Mountains. Starting at the North Pole and heading south to the South Pole, the 104th meridian west passes through: 104th meridian west The meridian 104° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole. The 104th meridian west forms a great circle with the 76th meridian east. In the United States, the western boundaries of North Dakota, South