In honor of George Washington’s birthday today, let’s take a moment to appreciate the contributions another founding father, Benjamin Franklin, made to marine science. Franklin was a true Renaissance man, with wide-ranging interests and notable achievements as a printer, author, inventor, scientist, diplomat and political theorist, to name just a few. On top of his other accomplishments, Franklin also had a forty year career as a postmaster and when his interest in mail delivery collided with his interest in science, the result was the first map of the Gulf Stream.
The Gulf Stream is a strong current of warm water that flows up the coast of North America and across the North Atlantic Ocean. The Gulf Stream, like other western boundary currents, plays an important role in transporting heat towards the poles, which affects coastal climates and can intensify storms. It’s also a feature you’d need to contend with if you were crossing the Atlantic on a ship.
While Ben Franklin was the Deputy Postmaster of the colonies, it was brought to his attention that British ships carrying mail required much more time – up to two more weeks – to reach New York than American merchant ships, even though the British mail ships were lighter and traveled a slightly shorter distance. Franklin consulted with his cousin, Timothy Folger, who was a Nantucket ship captain. Folger suggested that the British captains were unaware of the strong current flowing from west to east across the northern Atlantic while the American merchants knew to avoid it. Franklin combined the observations of Folger and other American ship captains with water temperature measurements he collected on transatlantic voyages and produced a map charting the current he called the Gulf Stream.
Although the purpose of the map was to spread knowledge of the Gulf Stream beyond the small community of New England ship captains, it was generally ignored by the British mail ships and failed to improve trans-Atlantic mail delivery times. Regardless, the map is still remarkable in its similarity to satellite images of the Gulf Stream.
To learn more about Ben Franklin and the Gulf Stream: