Geography Reference
In-Depth Information
Verbal scale
A
verbal scale
(also called
statement of scale
) communicates the relationship between map distance
and real-world distance in a sentence or sentence-like format. In Figure 5-1, “One inch equals one
mile” is the example. If you have a foot ruler handy, apply it to the bar graph and confirm that a dis-
tance of one mile as indicated on the bar graph is, in fact, an inch in length. Again, a given map has
a given scale, and therefore the different ways of expressing that scale must agree, which is precisely
what your ruler should demonstrate.
As far as most people are concerned, the verbal scale is particularly convenient for measuring dis-
tances on a map, provided a ruler is available. In the case of “one inch equals one mile,” one need
only measure the number of inches between two points to arrive at the number of miles that separ-
ate them on Earth. If, on the other hand, the verbal scale on another map reads “one inch equals 20
miles,” then the number of inches between the two points on the map needs to be multiplied by 20 to
render the actual distance.
Maps come in different scales. Thus, the scale you use to calculate distance on one map may
not be the same for the next map. Always check the scale before you calculate distance.
Whence comes the mile?
A mile is a unit of linear measurement that equals 5,280 feet. While most of the world
has adopted metric units (kilometers), Americans continue to express distance in miles,
which, therefore, commonly appear as units of measurement on maps made in the U.S.
But exactly what is a mile? And why does it consist of 5,280 feet instead of a more con-
venient figure, like 5,000?
“Mile” comes from the Latin
milia,
meaning thousand. In Roman times, a unit of linear
measure called the
milia passum,
or thousand paces, was common. Somehow, some-
body's thousand strides became a standard Roman mile, equal to about 1,650 yards.
This measurement became widely used in Britain following the Roman's invasion. After
the Empire's demise, however, the
milia passum
fell into disuse, although “mile” endured
in the British vocabulary as a word applicable to a substantial distance.
The mile's present length has its origins in medieval English agriculture. Back then, a
team of oxen was used to pull a heavy wooden plow. The farmer walked behind, mak-
