De Wit 1672 [Osher Collection]

Current Exhibition:

American Treasures
October 18, 2009 - August 21, 2010

American Treasures celebrates the reopening of the newly renovated and expanded Osher Map Library and Smith Center for Cartographic Education at the University of Southern Maine. It explores the library’s rich and varied collections and its mission to preserve those collections and make them accessible. Beginning with the foundational gifts by the Smith and Osher families, the library’s collections emphasize Maine and New England, followed in order by the United States, the Americas, and the (continued)

A New Chart of the Vast Atlantic or Western Ocean

(click on image to view in greater detail)

Carington Bowles English, 1724-1793 A New Chart of the Vast Atlantic or Western Ocean Copper engraving, hand-colored, 44.7cm x 55.1cm London, 1762

A New Chart of the Vast Atlantic or Western Ocean

The British mapmaker, Carington Bowles, produced this chart in 1762 "to show the course of sailing from one continent to the other."

Sailing from Europe, ships made a stop in the Madeira Archipelago or Canary Islands for final provisioning of food and water before heading south to pick up the Northeast Tradewinds. Then, they altered course to the west for the West Indies, Carolina and Virginia. The Northeast Tradewinds and North Equatorial Current always ensured a swift and dependable voyage. If headed for the port of Boston, or the cod fishing grounds on the Grand Banks of Newfoundland, they took a direct course in more northerly waters. As long as they did not wander too far south to encounter the Gulf Stream, ships made acceptable progress in the passage.

On the return voyage, Portuguese and Spanish ships rode the strength of the Gulf Stream northward from Florida until they reached the latitude of Virginia. There, they turned east to sail directly to the Azores, and back to their home ports. The choice for an eastward voyage at this latitude was determined less by any knowledge of a favorable current, than fear of the risk of meeting with English or French vessels. With piracy and privateering the order of the day, any ship of another nation was considered fair prey.

Euclid's theorem that "the shortest distance between two points is a straight line" obviously prompted the suggestion for the routes indicated for sailing from England to New York, or Virginia. But the shortest distance does not always equate with the shortest time. Ships sailing to New York had to battle against the prevailing southwest wind, as well as the Gulf Stream.