His dog and he are old, too old for roving, hence Thor Heyerdahl plans no more ocean voyages of the kind he has repeatedly made to startle the world.

Actually, the truth is a trifle less lyrical. He simply has not found any vessels that the authorities proclaim unfit for the open sea, but which he knows can sail across oceans.

He is best known -- and sometimes it hurts him, in a small way, because he has done other things of consequence -- for his incredible voyage from Peru to Polynesia in 1947 on a balsa raft, Kon-Tiki.

*Utterly impossible. So were his two voyages in 1969-70 from Morocco to the West Indies and Central America in boats made of papyrus reeds. But he is intensely interested in the anthropology of Easter Island and the distribution of food plants and many other things besides balsa and papyrus boats.

"I do not think of myself as a courageous man," he said yesterday, "and my boyhood friends would bear this out. I was an overly protected child -- my mother was 45 when I was born. Nobody could make me believe I could swim. Other people could swim, but I knew I'd sink. I never went to the sea, I always went to the mountains. I had a Greenland husky. This learnt me to live with the elements.

"When I was 7, I got my parents to give a room of the house to my collections. I had all the local flora and fauna, a kind of museum. Part of the floor was turned into a beach, with starfish and shells on it. I also had butterflies and bats. The bats I set out in the sun to dry for a while."

Advanced taxidermy was not one of his boyhood accomplishments and a certain smell overlay part of his collection, he now realizes.

He is in town to receive the Lindbergh Award of the Charles A. Lindbergh Fund. It is given each year to one whose life work has demonstrated a balance between advanced technology and protection of the natural world. The fund, which has 3,000 members, has given individual awards up to $10,000 to scientists, totaling $500,000 since 1977.

If you inquire of him whether his advanced technology consisted of sailing about in copies of ancient Egyptian papyrus boats (which polluted no harbor nor turned the sky black from smelting iron), he laughs and starts to explain but goes off on Lindbergh and never gets back to technology:

"I knew little about Lindbergh until this award, and now I am amazed. He was a generation ahead of most environmentalists in his understanding there must be a balance. Progress will continue, but there must be a balance in which the environment is not destroyed."

Which is all very well, but the solo flight to Paris is all anybody will remember.

"Yes," said Heyerdahl, "he once said, 'Nobody will let me fly beyond Paris.' And in a way it's true that nobody will ever let me sail other than in the balsa raft." He had not heard about the loss of the Pride of Baltimore, a two-masted schooner modeled on historical ships and used to promote the city of Baltimore. Four of the crew were lost and others cast adrift for five days after a sudden storm sank the vessel last Wednesday.

"The greatest security is not with hulled ships," he said, "but with wash-through vessels, in which the sea washes right on through the reeds that give less resistance.

"I have said I am not naturally courageous, and if I do something risky, like those voyages, I always plan a second way out. With the papyrus boats you can always hold on to something and float; they don't sink to the bottom.

"During the war I was a parachutist, and now it seems hazardous to me to get in a plane without a parachute. Where is the second way out? But of course we get used to it.

"It wasn't courage or madness that led me to the sea, but logic. I had genetic proof of plants in Polynesia that came from South America, long before the first white men. I knew about currents and boats -- it was well known that the Spaniards saw Peruvian boats far out at sea, large enough to hold horses.

"If experts said this boat or that could not sail in the open sea, I had the evidence of earlier voyages -- the plants, say -- and if they clearly had made these voyages centuries ago and if they had only one kind of possible boat to make them in, then the logic is clear -- they sailed in those boats, no matter what the experts might say about their seaworthiness.

"I never started a sea voyage unless there was a vessel known to have existed, but which experts said could not have made sea voyages. I copied the vessels and sailed them.

"A lot is not known. When I made boats of reeds in the Middle East, there was nobody to tell us that the reeds must be cut in August if the boat was to be seaworthy. We learned much from the Indians of Lake Titicaca -- it is wonderful the skills had been passed down for centuries there, but we Europeans did not know these things.

"Why do I now live in Italy? Well, I grew up on the Oslo Fjord, but with the ability to long to get off that fjord."

He is lean and lithe at 71, with blue eyes neither vivid nor faded but just blue, and he is of slighter build than a Viking ought to be. The Viking voyages to Greenland have been done often enough in modern times that he is not interested in repeating them, though he is thinking of a book about Scandinavian settlements in Greenland after the year 1000. (He has so far published seven books, including "Kon-Tiki" and "The Ra Expeditions.")

"I don't know if they actually had horns on their helmets," he said reflectively, turning down a lemon cake somebody had plopped in front of him. "They were, of course, good Catholics and established about 17 churches in North America before the 15th century."

His Norwegian name is pronounced Tore HAY-er-doll. People usually say HIGH-er-doll. The "ey" combination was pronounced "ay" even in English until the 17th century, with such survivals as grey, whey and they, as well as some proper names like Keynes.

He spoke of his mother again. Overprotective or not, she had great enthusiasm for "primitive people" and from her Heyerdahl picked up an interest in them. The world's greatest library on Polynesia, he said, is at Oslo, and even as a boy, when other kids were roaring about, he read book after book, all the books, about Polynesia. He knew before manhood he would be an explorer. He lectured on the Marquesas Islands in university courses before he ever visited them.

Society is the richer, surely, that he turned to Polynesia rather than a career of drying bats imperfectly in the sun. Life is chancy, but sometimes the lines fall in pleasant places that do not smell.