Читать книгу Geography For Dummies - Jerry T. Mitchell - Страница 53

Like Gridville, the world as a whole possesses a grid whose coordinates may be used to identify the absolute location of things. Indeed, that is why a Greek named Hipparchus invented the global grid more than 2,000 years ago. Though not necessarily the first with this idea — many credit the earlier ideas of Eratosthenes — he did leave us with what most people use today. (You can read more about Eratosthenes in Chapter 1).

As chief librarian at the great library in Alexandria, Egypt, Hipparchus compiled information about lands and cities all over the expanding Greek world. He saw the value of accurately locating objects on a map, but in those days that was easier said than done. Maps were notoriously inaccurate, due in good measure to lack of a systematic means of stating the location of things. So, Hipparchus set out to rectify the situation, and came up with the global grid that is still in use today (see Figure 3-2).

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FIGURE 3-2: The basics of the global grid.