ABSTRACT
Conventional projections form the third major type of map projection. These are projections which are neither equal area or conformal. The most useful of the conventional projections are the gnomonic, the azimuthal equidistant, the Miller, the polyconic, the Robinson, and the orthographic. Of lesser interest are the conical projections such as the perspective, and the simple conics of one- and two-standard parallels, the cylindrical projections such as the perspective, the plate Carree, and the Carte parallelogrammatique, and a selection of specialty projections, such as the Globular, the Van der Grinten, the Cassini, and the aerial perspective. This class of projections contains both world maps and maps limited to local areas of coverage. The world maps are represented by both cylindrical and pseudocylindrical projections. The outstanding feature of the gnomonic projection is that all great circles on the Earth appear as straight lines on the projection.
