Thor Heyerdahl (1914-2002), Norwegian adventurer and ethnologist, became famous in 1947 when he and an international crew sailed from Peru across the Pacific to French Polynesia in a home-built raft called the Kon-Tiki. Heyerdahl’s aim was to demonstrate that, since he was able to do it, ancient Peruvians could have done it, too. Thus, they did, he claimed, and Polynesia was settled from east to west from South America and not west to east from Asia as standard anthropology had it.

Archaeology, linguistics and the new science of DNA research have subsequently failed to support Heyerdahl’s claims. Conventional scholarship has weathered his assault. But he told a damn good story and helped create the field of experimental archaeology, in which people learn about the past by getting out there and doing it. His theories may have leaned toward the preposterous, but he sold a lot of books and riled up a lot of people.

One of those people was me. I remember quite vividly reading his The Ra Expeditions, recounting his 1970 voyage in a papyrus boat from Morocco across the Atlantic. This time, Heyerdahl and another hand-picked, international crew wanted to prove that the ancient Egyptians could have crossed the Atlantic in papyrus reed ships and made contact with pre-Mayan MesoAmerica, inspiring the natives to build their own pyramids, as those that now dot the jungles of Yucatan and Guatemala. I came across the book when I was a junior or senior in high school and devoured it. It made an impression on me which persists to this day.

No, I didn’t run out and build balsa wood boats and sail across Buzzards’ Bay. Here’s what sticks with me from Thor Heyerdahl.

As The Ra Expeditions recounts, Heyerdahl modeled his papyrus ship on paintings of such craft he and others found in Egyptian tombs. Some of these paintings showed the vessel’s rigging and construction in great detail. Heyerdahl saw to it that the craftsmen he employed for the ship’s construction followed these drawings faithfully. He constantly inspected their work to ensure their reproduction was accurate. It was.

Despite all the care that went into building the ship, at the last moment Heyerdahl had to make some considerable changes. Before they would allow the ship to sail, the local port authorities demanded that Heyerdahl equip it with a shortwave radio. Heyerdahl had followed strict weight limitations in the ship’s construction to guarantee the papyrus’ buoyancy would be sufficient to carry the crew. The authorities’ last-minute demand threw his calculations into the waste basket.

So Heyerdahl went back to the drawing board. He scoured the Ra for every possible piece of excess baggage he could jettison. But, even when he had stripped Ra down to her bare essentials, she was still overweight. He had to find something else to get rid of.

His eye fixed on a hawser, a thick rope, that extended from a fixed point  on the rear deck up to the curled-over tip of the Ra’s scorpion-tail stern. Here was a feature that was on all the drawings. But when Heyerdahl tested the hawser, he found that the tip of the scorpion’s tail stayed put without it. They did not need the hawser to keep the tail down. In this detail, at least, the ancient Egyptians hadn’t known what they were doing. A few quick chops with a handy ax and the hawser flew overboard. Ra lost a quick 50 pounds and looked as ship-shape as Marie on Nutri-System.(c)

She sailed.

About two-thirds of the way across the Atlantic, Heyerdahl noted that the ship seemed to be foundering. Close inspection revealed that the rear deck was depressed directly beneath the tip of the stern’s tail, at the exact point where the hawser had been fixed. Ra’s structural integrity had been compromised and she began to take on water. Heyerdahl realized to his shock that the hawser he had assumed had been there to keep the tail down had actually been there to keep the deck up.

The ancient Egyptians had known what they were doing after all.

Despite the crew’s herculean efforts, the Ra foundered east of Barbados. Ironically, the radio enabled them to call for help. Water over the gunnels, they were rescued by a private yacht.

There are many lessons to be drawn from this parable: government intervention made the crew less safe than it otherwise would have been; the radio was simultaneously the cause of Ra’s demise and the instrument of her crew’s rescue; and it was private action that saved them in the end.

But most salient, I think, is this: some things can work so well over such a long period of time, that succeeding generations can forget why their ancestors put them there in the first place. They can look like they are there to keep something, or someone, down. But in reality they are in place to support a structure that sustains us all, a function they perform so well that we can no longer imagine the structure capable of foundering.

But it can.