Scale
A globe is the only way to represent the earth with constant scale throughout the entire map in all directions. A map cannot achieve that property for any area, no matter how small. It can, however, achieve constant scale along specific lines.
Some possible properties are:
- The scale depends on location, but not on direction. This is equivalent to preservation of angles, the defining characteristic of a conformal map.
- Scale is constant along any parallel in the direction of the parallel. This applies for any cylindrical or pseudocylindrical projection in normal aspect.
- Combination of the above: the scale depends on latitude only, not on longitude or direction. This applies for the Mercator projection in normal aspect.
- Scale is constant along all straight lines radiating from a particular geographic location. This is the defining characteristic of an equidistant projection such as the Azimuthal equidistant projection. There are also projections (Maurer, Close) where true distances from two points are preserved.
Read more about this topic: Map Projection
Famous quotes containing the word scale:
“I love to weigh, to settle, to gravitate toward that which most strongly and rightfully attracts me;Mnot hang by the beam of the scale and try to weigh less,—not suppose a case, but take the case that is; to travel the only path I can, and that on which no power can resist me. It affords me no satisfaction to commence to spring an arch before I have got a solid foundation.”
—Henry David Thoreau (1817–1862)
“There is something in us, somehow, that, in the most degraded condition, we snatch at a chance to deceive ourselves into a fancied superiority to others, whom we suppose lower in the scale than ourselves.”
—Herman Melville (1819–1891)
“The perch swallows the grub-worm, the pickerel swallows the perch, and the fisherman swallows the pickerel; and so all the chinks in the scale of being are filled.”
—Henry David Thoreau (1817–1862)