[Terrestrial globe gores].
Relief shown pictorially.
Title supplied by cataloger.
Reissued by Giuseppe di Rossi in 1615.
Dedication in upper hemisphere: Illmo. viro optimaraq. artium amatori et Fautori D. Paulo Mellino Romano ...
In lower hemisphere: I. Hondius Lectori S. In locorum longitudine ... Longitudines incepimus non ab Insulis Fortunatis ut Ptolome[us], sed ab iis quae acores vocantur quod acus nautica ibi recta in septentrionem vergat Vale. Anno 1615.
Gores for a 19 cm. globe.
Available also through the Library of Congress Web site as a raster image.
LC copy: Fold lined and water stained. Mounted on cloth.
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.