When was the map of the gulf stream invented?

Answer 1

This answer is based on the research of a close friend of mine, Dr. Gerald H. Shinn, Professor Emeritus of Philosophy & Religion at University of NC Wilmington, who has made a recent study of this very topic. I have been privy to many of his conversations about this, and this answer is comprised of a rough synopsis of his research. It may have some minor errors, and it is by no means complete or detailed, but what is presented is generally accurate.

Benjamin Franklin was not the sole discoverer of the North Atlantic Current, or "Gulf Stream," as it is known. In fact, he was put on to its existence by his kinsman, a merchant Captain whose last name was Folger (Franklin's cousin or nephew, I can't recall). Captain Folger's discovery of it was the result of the unscientific but astute realization that a current of warmer-than-average, swiftly moving water could be detected and utilized to expedite shipping traffic in the Atlantic from West to East. Folger remarked to Franklin about this phenomenon and Franklin, who was at the time serving as Postmaster General of the Colonial American colonies, immediately grasped the advantages to be had by such a current and set about to verify and map it.

Franklin first chartered as vessel to follow Folger's rough outline of where the current should be picked up, and using specialized thermometers that he had ordered from England for this particular task, he tested the temperature of the water at various depths for the duration of the voyage, thus mapping the current and establishing its boundaries. Not content with just one experimental voyage, Franklin repeated the process and found the results to match the first trip. He may have made a third passage like the first two, but I can't recall this for certain. At any rate, he was the first to make a precise map of the current based upon scientific analysis and testing. His first map of the so-called "Gulf Stream" was published in the early 1750s, I believe (though I can't be certain, again) in the Bibliotheque Nationale. I might be quite mistaken on this last point, so don't hold me to it, but the rough date is correct.

It's worth noting that even Folger and Franklin were not the first people to discover and exploit the North Atlantic Current; the Spaniards, nearly a century before, had made the same discovery - absent any known scientific verification - and had used the Current to ferry their treasure ships in safety from the Americas back to Europe. They had maintained the secret well, however, in order to safeguard the fortunes of goods and gold that were their most prized cargo from the West. Unfortunately for them, the secret could not be kept under wraps and others, like Folger, eventually noticed the secret shipping lane as well.

Answer 2

The map of the Gulf Stream was not invented but rather first charted by Benjamin Franklin in 1769. He produced a chart of its course and speed, which was instrumental for ships navigating the Atlantic Ocean.