- Cartography is actually the art of making maps or charts, but it has also been
misused as a general term for the study of maps. The cartographer is the map maker and they tend
to limit the definition of the term to the final stages of making and printing the map. Others include
the planning, aerial photography, field surveys, editing, etc.
- A cadaster is a map showing the extent, value, and ownership of land as a basis for
taxation. The adjective, cadastral, or cadastral map, is used in many family history textbooks. It is
simply a land ownership map.
- A contour map is one that shows elevations by drawing curved lines along the same
elevation. It therefore clearly marks hills and valleys. The difference between two contour lines is
termed the contour interval.
- DOQ stands for Digital Orthophoto Quadrangles. These are aerial photographs available
digitally on the computer which cover large rectangular sections of land.
- DRG stands for Digital Rastergraphics. These are simply topographical maps that have been
digitized for the computer.
- A grid is a framework of parallel or crisscrossed bars. It is short for the word "gridiron." On
a map the bars form squares of uniform size, and they are used as starting points for drawing maps.
Numbers used to indicate these points are called grid coordinates.
- Latitude is the angular distance north or south of the equator. The rings around the
earth form parallel horizontal lines.
- A legend is simply the key to a map. It is an explanatory caption to a map which explains
what all the symbols mean.
- Longitude is an angular distance east and west of an imaginary vertical line that runs
through Greenwich, England, called the Prime MERIDIAN. A meridian is a great vertical circle
passing from pole to pole. These bands form parallel vertical lines around the earth. Together, latitude
and longitude form a grid on which the starting point for maps are marked.
- The word "plat" means braided, and the plat maps show owners of seemingly interwoven or
braided tracts of land. It is a diagram of that land drawn to scale using surveys. The phrase "Plat
map" did not appear in the American Heritage dictionary. A mosaic is an assemblage of overlapped
- The word quadrangle is a term actually specific to the map sheets put out by the
US Geological Survey. They created the term. In geometry, the four sides of the plane do not have
to be rectangular. On college campuses, the quad is a rectangular area surrounded by buildings.
- In art and architecture, relief is defined as the projection of forms or figures from a flat
background; however, in map making, the relieve map does show the land configuration through the
use of contour lines, shading, and coloring, but it can be flat. If the map is three dimensional, it is
termed a raised relief map.
- A thematic map follows a theme. Perhaps the map shows the area of grape agriculture
in Erie County, Ohio.
- A topographic map shows the exact physical features of a region.
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