Portolan Charts and Atlases
During the 16th and 17th centuries, the representation of oceans and seas on maps was a blend of practical navigation and artistic expression. Oceans were sometimes depicted with wavy lines or stippling, distinguishing them from landmasses by showing the intersection between seas and the shore. For example, the Carta Marina (1539) has parallel, wavy lines going across the map horizontally to indicate which areas were ocean. On other maps, oceans were simply blank spaces marked with pictures of boats, fish and sea monsters, reflecting the blend of knowledge and imagination that characterized mapmaking at the time. For instance, the Atlas Universal (1557-1577) by Diogo Homem has depictions of ships, fish, and sea monsters on any page where the ocean is included. These embellishments not only added decorative flair but also served as a way of representing the unknown and dangerous nature of maritime exploration.
Maps frequently included wind heads, symbols that represented the eight principal winds. These wind heads were typically illustrated as human faces each pointing in a different direction, corresponding to the primary compass points. Some cartographic traditions used a twelve-wind system. This system expanded upon the eight-wind system by dividing each of the cardinal directions into three additional points, creating more precision in wind direction.
The Portolan Atlas of 1546 by Battista Agnese is an example of a map that used the twelve-wind model. On this portolan chart the twelve winds are drawn as cherub heads sitting on blue clouds placed around the map, framing it. In addition to wind heads, rhumb lines were often drawn on maps to show consistent compass bearings, allowing sailors to follow a steady course across the seas. The Atlas Universal (1557-1577) by Diogo Homem, the Castiglioni Map (1525) by Diogo Ribeiro, and the Miller Atlas (1519) by Lopo Homem, Pedro Reinel, Jorge Reinel, and António de Holanda all include detailed networks of rhumb lines that would have been used by sailors to stay on course.
Works Cited
Maria Fernanda Alegria, Suzanne Daveau, João Carlos Garcia, Francesc Relaño.“Portuguese Cartography in the Renaissance.” in The History of Cartography, vol. 3, part 1, Cartography in the European Renaissance, ed. David Woodward. Chicago: University of Chicago Press, 2007.
Eric H. Ash.“Navigation Techniques and Practice in the Renaissance.” in The History of Cartography, vol. 3, part 1, Cartography in the European Renaissance, ed. David Woodward. Chicago: University of Chicago Press, 2007.
Mukerji, Chandra. “Printing, Cartography and Conceptions of Place in Renaissance Europe.” Media, Culture & Society 28, no. 5 (2006): 651–69. https://doi.org/10.1177/0163443706067020.