[Boston Harbour, with the surroundings, &c.
Scale ca. 1:24,000.
Title from William Faden's Catalogue of a curious and valuable collection of original maps and plans. 1862.
Manuscript, pen-and-ink and watercolor.
Relief shown by shading and hachures. Depths shown by soundings.
Oriented with north toward the upper left.
Available also through the Library of Congress Web site as a raster image.
LC Maps of North America, 1750-1789, 943
AACR2: 100; 650/1; 650/2; 651/3; 651/4; 651/5; 650/6
The word portolan comes from the Italian adjective portolano, meaning "related to ports or harbors", or "a collection of sailing directions". Portolan charts are maps based on compass directions and estimated distances observed by the pilots at sea. They were first made in the 13th century in Italy, and later in Spain and Portugal where they considered to be state secrets. The English and Dutch found the description of Atlantic and Indian coastlines extremely valuable for their raiding, and later trading, ships. The oldest survived portolan is the Carta Pisana, dating from approximately 1296 and the oldest preserved Majorcan Portolan chart is the one made by Angelino Dulcert who produced a portolan in 1339.