A Map is a picture of the whole, or of a part, of the Earth’s surface, on a plane or level. Generally the top of a map represents north; the right hand side, east; the bottom, south; the left hand side, west. West, east, north, and south, are called the Cardinal Points.
Young persons in studying maps, imbibe an idea that the top of a map represents the highest part of a country; but this is a great mistake, as will be at once seen, by looking at the maps, and finding many rivers flow north, and recollecting that water cannot flow up hill. That part of a country is the most elevated, which contains mountains, and where rivers have their source.
Cities and towns are represented on maps by an o; rivers, by black lines running irregularly; mountains, by dark shades; deserts, by clusters of small dots; boundaries, by dotted lines.
The Axis of the earth is an imaginary line passing through its centre from north to south. The extremities of the Axis are called the Poles.
The Equator or Equinox, is an imaginary circle, surrounding the Earth from west to east, at an equal distance from the poles. [See Map of the World, fig. 2].
A Meridian, or Line of Longitude, is a circle crossing the equator at right angles, and passing through the poles. [See fig. 4].
Parallels of Latitude, are lines, drawn across maps, representing circles equally distant in every part from the equator. [See fig. 3].
The Tropics are two circles parallel to the equator, at about 23 degrees and 28 minutes from it. The northern is called, the Tropic of Cancer; and the southern, the Tropic of Capricorn. [See fig. 2].
The Polar Circles are drawn at 23 degrees and 28 minutes from the poles. The northern, is the Arctic, and the southern, the Antarctic Circle. [See fig. 2].
A Degree is the 360th part of a circle, and contains 69½ English miles; each degree is divided into 60 equal parts, called minutes; and each minute into 60 equal parts, called seconds. They are marked (°) degrees, (’) minutes, (”) seconds.