[Portolan chart of the Mediterranean and Black Seas with the west coast of Spain and Portugal] /
Portolan chart with seaport names given for all coastlines.
Title devised by cataloguer.
Fragmentary signature on upper right portion leading into neck reads "Io Placid...".
Oriented with north to the right (indicated by fleurs-de-lys).
Contains 10 small and 4 large compass roses centered on Sicily.
LC Nautical charts on vellum, 14.
Pen-and-ink and goauche, with traces of gilding.
Includes 2 scale bars (unidentified units), fragment of an illustration on the neck, and many illustrations throughout.
Available also through the Library of Congress Web site as a raster image.
Pre - 1600s maps, atlases and manuscripts
Ancient Maps from the Library of Congress. 13th -18th Century Maps.
The geography discoveries and the new printing techniques resulted in maps that can be cheaply produced. Since a globe remains the only accurate way of representing the spherical earth, and any flat representation resulted in distorted projection. In 1569, Mercator published a map of the world specifically intended as an aid to navigation. It used a projection now known by Mercator's name, though it has been used by few others before him, based on a system of latitude and longitude that dated back to Hipparchus. Mercator's projection greatly enlarged territories as they recede from the equator. The distortion of Mercator's projection is a benefit to navigators since Mercator achieves a matching scale for longitude and latitude in every section of the map. A compass course can be plotted at the same angle on any part of Mercator's map. As a result marine charts still use this projection. By the time of his death in 1595, Mercator has either published or prepared large engraved maps, designed for binding into volume form, of France, Germany, Italy, the Balkans, and the British Isles. Mercator's son issues the entire series under the title "Atlas": "Atlas sive Cosmographicae Meditationes." The name becomes the word for a volume of maps.