A thematic map is a type of map that portrays the geographic pattern of a particular subject matter (theme) in a geographic area. This usually involves the use of map symbols to visualize selected properties of geographic features that are not naturally visible, such as temperature, language, or population. In this, they contrast with general reference maps, which focus on the location of a diverse set of physical features, such as rivers, roads, and buildings. Alternative names have been suggested for this class, such as special-subject or special-purpose maps, statistical maps, or distribution maps, but these have generally fallen out of common usage. Thematic mapping is closely allied with the field of Geovisualization.
Edmond Halley's New and Correct Chart Showing the Variations of the Compass (1701), the first chart to show lines of equal magnetic variation.
Jodocus Hondius was a Flemish and Dutch engraver and cartographer. He is sometimes called Jodocus Hondius the Elder to distinguish him from his son Jodocus Hondius II. Hondius is best known for his early maps of the New World and Europe, for re-establishing the reputation of the work of Gerard Mercator, and for his portraits of Francis Drake. He inherited and republished the plates of Mercator, thus reviving his legacy, also making sure to include independent revisions to his work. One of the notable figures in the Golden Age of Dutch cartography, he helped establish Amsterdam as the center of cartography in Europe in the 17th century.
Jodocus Hondius on a 1619 engraving by Colette van den Keere
Leo Belgicus (1611).