Atlantic: A Vast Ocean of a Million Stories. Simon Winchester

as St Mary’s flower or the rose of Jericho to bring back as proof. It didn’t work: none of this convinced the sceptical prince Henry, who promptly ordered Gil Eannes to go out to sea once again.

      So back he went the following year, 1435, this time with a companion — a man who was also a household servant, though a spare-time sailor - and they took their puny fishing barca on almost the exact same plotted route, with its wide westerly diversion south of the Canary Islands. The men landed at almost the same African coastal spot, they named a river, they saw the footprints of men and the hoofprints of camels, and thus realised that the Torrid Zone was peopled, and they came back to a finally credulous Henry the Navigator, and in consequence to a brief period of court rapture followed by a lengthy period of public obscurity.²¹

      And the two ventures did the necessary trick. Within months other expeditions had set out from the Portuguese harbours, and they fanned out along the at-long-last-accessible coast of Africa to explore it, round it, and then eventually to head off east beyond the continent of Africa, to the great treasure grounds of the Indies.

      The ships grew steadily in size — from the tiny barcas used by Eannes, to the three- and four-masted caravels, and the gigantic naus employed on the spice runs of the sixteenth century. The equipment carried on the ships’ bridges became more sophisticated: the astrolabe was soon to be invented, the compass to be employed, sounding wires to be made long enough to deal with exceedingly deep waters, and tide tables and sight reduction tables to be published.

      The mariners became ever more adventurous, and history is littered with their names: Bartholomew Diaz, who first rounded the Cape of Storms; Vasco da Gama, who first went to India; Pedro Cabral, the first to land in Brazil; Alfonso d’Albuquerque, first in Malabar, Ceylon, and Malacca; and all those other sailors whose names — Fernando Poo, Tristan da Cunha, Luis Vaez de Torres - are memorialised in islands or straits (or as these three are remembered, for a slaving colony off Africa, a dangerous volcano in the far South Atlantic, and a narrow passage between New Guinea and the northern tip of Australia). Perhaps greatest of them all, though claimed by others, was Ferno de Magalhães, the would-be circumnavigator who was born in Portugal, but sailed for Spain, and died as Ferdinand Magellan in the Philippines in 1521. All of these indefatigable sailors and a score more - who mostly came from a Portugal of which it used to be said such a tiny land to live in, but the whole world to die in — came to be legatees of the pioneering sailing techniques of Gil Eannes. They followed in his wake, both literally and figuratively, to begin the organised acquisition of knowledge about the Atlantic and all the other oceans besides.

      3. MOVING THE WATERS

      It has to be remembered that until Amerigo Vespucci, there was no knowledge — nor even a suspicion or a hint — that the Atlantic was a separate sea. Culturally, this was an ocean that until the end of the fifteenth century was not known to exist. Then, and at a stroke, with Vespucci’s voyage, the Atlantic Ocean was born; suddenly it was there.

      With this realisation of a brand new sea, anchors were weighed and sails unfurled, brass clocks were wound and heaving lines leaded. Scientists were appointed and chart makers assigned, and bold and fearless skippers in their legions took their little ships out of port and headed off to measure and to mark this new body of water.

      At the edges of a sea, it is the daily tides that prove the most obvious features to measure and record. Out in the deeps, beyond the influence of tides, the seaman must look for other things: for the size of waves and the direction of swells, the tenor of storms, the press of fish and birds, the depths beneath the bow. And, most importantly, the unexpected and initially mysterious ways that the waters appear to move.

      Since these motions are among the most clearly influential on the passage of any ship - as Gil Eannes experienced off Cape Bojador, and then made use of - they were noticed very early on in the exploration of the Atlantic. They seemed like great underwater rivers, or torrents. Currents-from the French, things that run — were the first of the ocean’s many unseen features to become properly known. And perhaps no stream was more famously so than that immense rushing extension of the North Equatorial Current known, from Florida, where it begins, to the west of Scotland, where it ends (with palm trees growing beside the waters that it so conveniently warms), as the Gulf Stream.

      Like many mariners around the world, Columbus noticed the currents — and here the exceptionally strong currents that seemed to him so unusually prevalent in Caribbean Atlantic waters. “I found the sea ran so strangely to the westward,” he wrote in the log of his third voyage, describing his passing through the notorious Dragon’s Mouth, between Trinidad and the Venezuelan mainland, “that between the hour of Mass, when I weighed anchor, and the hour of Complines, I made sixty-five leagues of four miles each with gentle winds …” There are also accounts by Peter Martyr, the Spanish court historian who, coincidentally, was among the first to recognise the huge potential importance of the Gulf Stream, of a vain attempt by Columbus to take a sounding off the coast of Honduras, only to have the “contrary violence of the waters” force his lead upward and never once allow it to touch bottom.

      But Columbus was too far south to experience the power of the Gulf Stream. That happy discovery was left to his successor, Ponce de León,²² who found it in 1513, while on his quest for the fountain of youth - a search that eventually won him the ironic substitute of being the first European to find Florida. He was charting the topography of this new coast - thinking it to be a large island, the flowered one.

      Ponce made rendezvous with two other ships coming north from Puerto Rico, and the three vessels set themselves to sailing farther south, keeping Florida just in sight on their starboard side. One afternoon, when they were perhaps thirty miles from shore, Ponce de León and his fellow sailors suddenly found themselves swept into and caught up in “a current such that, although they had a great wind, they could not proceed forward, but backward, and it seems that they were proceeding well; at the end it was known that the current was more powerful than the wind.” Whatever was the cause, this wide river of water, which he soon found swept northwards and in time turned towards the east, had huge and unstoppable power. The Spaniard became swiftly aware of its commercial implications :that however difficult it might be for ships to beat their way westwards across the middle reaches of the Atlantic, the power of this submarine river offered the guarantee that anyone who floated onto it would be taken home, in style and with considerable speed. Empty galleons might find the outbound passage a trial, but treasure-laden and stately, they could dip home from the Isthmus of Panama, pushed along by this new-found current, with a very welcome dispatch.

      Riding the Gulf Stream home quickly became a kind of navigational sport. The traditional means of return to Spain -though it was barely a tradition, since the passage had only been opened two decades before - was to use the winds alone, to take advantage of the westerlies that blew for most seasons in the middle latitudes of the ocean. But there was a risk inherent: on a voyage from the Main it was tempting to turn east, to turn for home, too early, and in doing so chance becoming becalmed in the fickle breezes of what is now known as the Bermuda High.Now that the Gulf Stream was known, the solution was simple — though, as with the sharp turn to sea made by Gil Eannes in rounding Cape Bojador, it was also counterintuitive. He headed west to go south; homebound Atlantic skippers needed to head north to go east.

      Coming from the Isthmus they would tease out the Gulf Stream’s beginnings in the Caribbean and then more properly in the shallow waters off what is now known as Cape Hatteras. Once it was found, a homebound sailor would attempt to slot his ship neatly into the sixty-mile-wide band of its warm, fast flowing waters, let the current carry him north at nearly six miles per hour, and then as it turned, head eastwards with it too, following its warm blue stream for most of its two-thousand-mile curving, Europe-bound length.

      Once this marvel had been discovered, and once its spread and its speed had been mapped and measured, the Gulf Stream swiftly became an object of widespread fascination. Its most resolute early champion was perhaps its most improbable: the polymathic American statesman and founding father, Benjamin Franklin. In a most remarkable