By: Jack Swift
Johnson County Historian
Sometimes we hear someone say that a person or activity really put a site such as a town or place on the map. There are people who have gone on from Mountain City to lead successful lives in far away places and even in distant lands. When they become well known in a positive way, we often say those people are putting Mountain City, Johnson County or whatever the site may be “On The Map.” A special crop such as the green bean farming and marketing that occurred a few decades ago put Johnson County on the map with the slogan: The Green Bean Capital of the World.”
While thinking about putting places and activities on the map, I began to think about maps in general and how they are used in our daily lives. Maps fascinate me. Whether they are flat in an atlas, folded as in a road map or on a globe. Mapping has been developing over a great amount of time. In the early days maps were difficult to make and took up a great amount of time. Also they were considerate a work of art. Therefore, owning them was often looked upon as status symbols.
Cartography (the art of map making) remained slow until Johannes Gutenberg’s invention of the printing press. As maps became more plentiful, they became more accessible to the public. And unlike earlier days, the tools and techniques of map making have improved tremendously. Modern satellite systems are being used to make maps easier and more precise.
Since the earth is not a precise sphere, map making must account for that. Also, putting a curved surface on a flat plane presents problems. A projection must be utilized to make the type of map that is needed. If a surface can be transformed onto another surface without stretching, tearing, or shrinking then the surface is said to be an applicable surface The sphere or ellipsoid are not applicable with a plane surface so any projection that attempts to project them on a flat sheet will have to distort the image. A surface that can be unfolded on unrolled into a flat plane or sheet without stretching, tearing or shrinking is called a developable surface. The cylinder, cone and the plane are all developable surfaces they can be unfolded into a flat sheet without distorting the projected image.
The next time we look at a map in an atlas may we keep in mind the kind of projection that was needed to make the map readable and accurate.