Today in the world there is not one area that would not have learned the man, or at least had not visited!The more information that appeared on the surface of the planet, the more urgent the question arose of determining the location of an object.Meridians and parallels, which are elements of degree grid, help to find the geographical address of the desired points and facilitate the process of orientation of the map.

## History of Cartography

Humanity did not immediately come to this simple method for determining the coordinates of the object, as the calculation of its longitude and latitude.Familiar to all of us from school, basic line gradually appeared in the sources of cartographic knowledge.Below is information on several key stages in the history of the development of sciences like geography and astronomy, which led to the creation of modern civilization cards with a comfortable degree grid.

- One of the "founders" of the natural sciences is considered - Aristotle, who first proved that the planet has a spherical shape.

- ancient travelers were very observant of the Earth, and they noticed that the sky (by stars), easily traced direction C (north) - Yu (south).Here is the line and became the first "meridian" analogue which can now be found on the very simple map.
- Eratosthenes, who is better known as the "father of science of geography", made a lot of small and big discoveries that influenced the formation of geodesy.He first used skafis (ancient sundial) to calculate the height of the sun over the territory of different cities and have noticed a significant difference in their measurements that depend on the time of day and season.Eratosthenes found a link between such sciences as astronomy and geodesy, thereby making it possible to perform many studies and measurements of terrestrial areas by means of the heavenly bodies.

## degree grid

Numerous meridians and parallels intersect on a map or globe together in a geographical grid, consisting of "squares".Each cell is limited by its lines, which have a degree.Thus, using this network can quickly locate the desired object.Many atlases structure is constructed so that individual pages are considered different squares, which enables a systematic study any territory.With the development of geographical knowledge improved and the globe.Meridians and parallels are at the very first models, which if not contained all reliable information about the objects of the Earth, but it gave an idea of the approximate location of the desired points.Modern maps are essential elements that make up the degree mesh.With her the coordinates.

## elements degree grid

- Pole - North (top) and South (bottom) are the points where the meridians converge.They are places of exit virtual line, which is called the axis.
- Arctic Circle.Since they begin borders polar regions.Arctic Circle (South and North), located on 23 parallels toward the poles.
- prime meridian.It divides the Earth's surface in the eastern and western hemispheres, and has two more names: Greenwich and Basic.All meridians are of equal length and on the surface of the globe or map connecting pole.
- Equator.He is the longest parallel, find their way to the W (West) to B (east), which divides the planet in the Southern and Northern hemisphere.All other lines parallel to the equator, have different sizes - their length decreases towards the poles.
- Tropical.They are also two - Capricorn (South) and Cancer (North).Tropical located on the 66th parallel north and south of the equator.

## How to meridians and parallels the desired point?

Any object on the planet has a latitude and longitude!Even if he is very, very small or, on the contrary, quite big!Identify the meridians and parallels object and find the coordinates of the point - the same effect, because it determines the degree of the main lines of the geographical address of the desired area.Below is a plan of action that can be used when calculating the coordinates.

## algorithm for determining the geographical address of the object on the map

- for the correct geographical name of the object.Annoying errors happen because of the banal lack of attention, such as the pupil made a mistake in the name of the desired point, and has identified the wrong coordinates.
- Prepare satin, a sharp pencil or a pointer and a magnifying glass.These tools will help to more accurately determine the address of the desired object.
- Choose the large-scale map of the atlas, which caused the desired geographic point.The smaller scale of the map, the more errors occur in the calculations.
- determine the relationship of the object to the basic elements of the grid.The algorithm of this procedure, submitted after the paragraph: "The calculation of the size of the territory."
- If the required point is not directly on the line marked on the map, find the next, which have numerical designation.Degree line, usually indicated on the perimeter of the card, at least - on the line of the equator.
- when determining the coordinates, it is important to find out, through any number of degrees parallels and meridians are located on the map and correctly calculate the unknown.It must be remembered that the elements of degree grid, in addition to the main lines can be drawn through any point of the Earth's surface.

## calculate the size of the territory

- If you want to calculate the size of the object in kilometers, it is necessary to remember that the length of one degree grid lines equals - 111 km.
- to determine the extent of the object with W to E (if it is completely located in one of the hemispheres: East or West) is sufficiently greater latitude from one of the extreme points, subtract and multiply lesser number by 111 km.
- If you want to calculate the length of the territory from N to S (only if it is all located in one of the hemispheres: South and North), it is necessary from a larger degree of longitude one of the extreme points, subtract the smaller, then multiply the total by111 km.
- If the property passes Greenwich meridian, to calculate its length with W on E latitude extreme points of this area are added, their sum is then multiplied by 111 km.
- If on the territory of the object is determined by the equator, to determine its extent with N on S must be added to the degrees of longitude extreme points in this direction, and the resulting sum is multiplied by 111 km.

## How to determine the ratio of the object to the main elements of degree grid?

- If the object is below the Equator, then its latitude will be just south if the above - north.
- If the desired point is located to the right of the prime meridian, the longitude is east it if the left - west.
- If the object is above the 66th degree parallel of north or south, it enters the corresponding polar region.

## Defining coordinate mountains

Since many mountain ranges are of great length in all directions, and the meridians and parallels intersect such objects have different degree value, the process of determining the geographical address accompanied by many questions.The following options are available calculate the coordinates of the high areas of Eurasia.

## Caucasus

most spectacular mountains are located between the two water areas of the continent from the Black Sea to the Caspian Sea.Meridians and parallels the Caucasus Mountains have different degrees, so what are considered crucial for the address of the system?In this case, we focus on the highest point.That is, the coordinates of the mountain range of the Caucasus - a geographic address peak Elbrus, which is equal to - 42 degrees 30 minutes north latitude and 45 degrees east longitude.

## Himalayas

highest mountain system on our continent - the Himalayas.Meridians and parallels of varying magnitude-degree, cross this place as often as the above-mentioned.How to determine the coordinates of the system?Likewise, as in the case of the Ural mountains, we focus on the highest point of the system.Thus, the coordinates coincide with the location of the Himalayas Qomolangma peak, and it is - 29 degrees 49 minutes north latitude and 83 degrees 23 minutes and 31 seconds east longitude.

## Ural Mountains

The longest in our continent - the Ural Mountains.Meridians and parallels with different degree values intersect the object in different directions.To determine the coordinates of the Ural mountains need to find their center on the map.This point will be the geographic location of the object - 60 degrees north latitude and the same longitude.Such a method of determining the coordinates of the mountains is acceptable for systems having a large length in one direction or in both.