This Old Map: Benjamin Franklin's Gulf Stream, 1786

Thanks to the jet stream, westbound flights across the Atlantic take longer than eastbound ones. In the centuries before air travel, sailors dealt with a related time-sucking natural phenomenon, until a famous American intervened with “A Chart of the Gulf Stream.”

Benjamin Franklin and his cousin, Timothy Folger, are credited with naming and mapping the Gulf Stream for the first time—the warm, strong ocean current that pushes northeast from the Gulf of Mexico, up the Atlantic coast, towards Europe. Though there were many editions, the map pictured above was printed by the American Philosophical Society in 1786, and now belongs to the Library of Congress.