Gordon Anderson, age 12, of Sloan, Iowa,

How do latitude and longitude show location?

Sioux City, Iowa, is at Latitude 4.2 degrees, 30 minutes North and Longitude 96 degrees, 30 minutes West. This information tells exactly­ where this city is located on the face of the globe. The neat system of latitude and longitude is man‑made. For tho car provides only two key ports of natural location. They are the geographic poles, the ends of the axis around which the world rotates. These are the two key points for the lines of latitude and longitude by which main has divided the surface of the globe Into sections.

Man invented the equator, which runs around the wide waist of the world exactly half way between the two poles. It is Latitude 0 degrees and it divides the world into the northern and southern hemispheres, The degrees of latitude are parallel circles cutting the globe into flat slices between the equator and the poles. They average a little less than 70 miles apart and each degree or parallel is subdivided into 60 minutes and each minute into 60 seconds of distance. Latitude 10 degrees South is about 700 miles south of the equator. Latitude 90 degrees South is the South Pole.

Its latitude tells us that Sioux City is almost 3,000 miles north of the equator. But so are many other places, for the same latitude runs clear around the globe. We need the lines of longitude to tell us that spot it occupies in the circle of latitude. The degrees of longitude are called meridians and they run from pole to pole. They divide the globe into the eastern and western hemispheres and slice it Into 360 orange sections. Each degree also is divided into 60 minutes and each minute into 60 seconds of distance.

There is no natural clue for dividing the globe into east and west, so man had to chose a division.

It was agreed long ago to make this line pass from pole to pole straight through the Greenwich Observatory, near London. This is Longitude degrees, the Prime Meridian, and other degrees are east or west of it.

When it reaches the poles, the line runs down the opposite side of the globe ‑ but it is no longer the Prime Meridian. It becomes Longitude 180 degrees. Together, these two half circles divide the globe into east and west. The longitude of Sioux City tells us that it is west from the Prime Meridian, about a quarter of the distance around the globe.

The meridians cut the equator into 360 equal parts and here they are about as far apart as the parallels. The distance between them narrows as they taper together to meet at the poles. The rectangles of parallels and meridians become narrower the farther we get from the equator. Butt each rectangle has its own numbers of latitude and longitude, different from every other. Its subdivisions of minutes and seconds give the exact location, north or south and east or west, of every spot on the face of the earth.