Читать книгу Geography For Dummies - Jerry T. Mitchell - Страница 55

While the Gridville grid consists of real roads, the global grid consists of imaginary lines of latitude and longitude (see Figure 3-2). Latitude lines go across the map — latitude comes from the Latin latitudo, meaning breadth, or the measure of the side-to-side dimension of a solid. Longitude lines run from top to bottom — longitude comes from the Latin longitudo, meaning length. This makes sense because when viewed on a globe, lines of longitude are generally lengthier than lines of latitude.

Similar to the roads in Gridville, the global grid contains a principal line of latitude (the equator) and a principal line of longitude (the prime meridian). All other lines of latitude and longitude are named and numbered respectively from these starting lines. It makes sense, therefore, that if you want to make like Hipparchus and draw a grid on a globe, then these are the first two lines you would draw. But where would you put them, and why?