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:
“The most perfect political community must be amongst those who are in the middle rank, and those states are best instituted wherein these are a larger and more respectable part, if possible, than both the other; or, if that cannot be, at least than either of them separate, so that being thrown into the balance it may prevent either scale from preponderating.”
—Aristotle (384–322 B.C.)
“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)
“With a defeated joy,
With an auspicious, and a dropping eye,
With mirth in funeral, and with dirge in marriage,
In equal scale weighing delight and dole.”
—William Shakespeare (1564–1616)