Exquisita & magno aliquot mensium periculo lustrata et iam retecta Freti Magellanici facies : eijgentlicke asbeeldinghe der Magellanischer Strate die nu met veel gevaers eitelijeke Maenden doorsien van nieus ondecktis.
Relief shown pictorially. Depths shown by soundings.
From Gerardus Mercator's Atlas sive Cosmographicae meditationes de fabrica mvndi et fabricati figvra. 1611.
Oriented with north to the bottom.
Includes panoramic view and col. ill.
Text on verso.
LC copy annotated in pencil in lower right margin: Gravure de 1570 par Ortelius.
Available also through the Library of Congress Web site as a raster image.
Gift; John P. Cosgrove; 2010.
Ancient Maps from the Library of Congress. 13th -18th Century Maps.
In the 17th century, maps took a huge leap forward. Mathematical and astronomical knowledge necessary to make accurate measurements had evolved. English mathematicians had perfected triangulation: navigation and surveying by right-angled triangles. Triangulation allowed navigators to set accurate courses and produced accurate land surveys. Seamen learned to correct their compasses for declination and had determined the existence of annual compass variation. Latitude determination was greatly improved with the John Davis quadrant. The measurement of distance sailed at sea was improved by another English invention, the common log. Longitudinal distance between Europe and Québec was determined by solar and lunar eclipses by the Jesuit Bressani in the 1640s and by Jean Deshayes in 1686. With accurate surveys in Europe, the grid of the modern map began to take shape.