ABSTRACT
Coordinates are slippery devils. A stake driven into the ground holds a clear position, but it is awfully hard for its coordinates to be so certain, even if the figures are precise. For example, a latitude of 40° 25′ 33.504″ N with a longitude of 108° 45′ 55.378″ W appears to be an accurate, unique coordinate. Actually, it could correctly apply to more than one place. An elevation, or height, of 2658.2 m seems unambiguous too, but it isn’t.
