New York; NOBODY IS MORE surprised at the way The Dragons of Eden: Speculations on the Evolution of Human Intelligence has captured a high possition on the national nonfiction best-seller lists than the author himself, Carl Sagan, and the publisher, Random House. Random has just returned to press with a ninth printing, bringing the total up to 115,000 copies, and that in itself is an indication that they have not yet made that great leap of faith. Those are pretty cautious printings, and apparently more to fill back orders than to flood the bookstores with copies. Still, 115,000 copies in two months of a book that is pretty inaccessible to all but the most intelligent reader is a surprise, not only to Dr. Sagan and Random House, but to all of us who subscribe to the late H. L. Mencken's theory that nobody ever went broke underestimating the intelligence of the American public. Sagan is not a science writer, but a scientist who writes, and that distinction has never brought his books the wide audience that many popularizers enjoy.

So what would account for the best-seller status of Dragons? "It says that people are perfectly willing to read things where they have to use their minds. We are thinking beings and I believe people enjoy using their thinking apparatus." That's the opinion of Carl Sagan. But Random House admits that it didn't hurt that Sagan has appeared on the Tonight Show some eight times in the last two years. Being seen with Johnny Carson can give you that stamp of popular approval, even when you're a professor of astronomy and space sciences at Cornell University, as well as director of the Laboratory for Planetary Studies.

Talking to Carl Sagan is not like interviewing any other best-selling author. Authors are minutely involved in the promotion and hype and money-coining apparatus of the publishing-author tour process, but Sagan has very obviously put Dragons behind him, delighted and gratified though he is with its success. Space is his arena, and it's a vast one. While other authors are talking about their future plans for another best seller, Sagan's workload goes something like this: He is recording a 13-part series, Man and the Cosmos (that's not the soccer team, but the universe) for National Educational Television. He's in charge of something called the Voyager Record. As you may recall, when Pioneer X and Pioneer XI left the solar system, they carried with them the artifacts of mankind, for other intelligences to discover in the future. They also bore a plaque (see illustration above), designed by Carl Sagan, bearing a pictograph of man and woman and greetings from earth. Now, with two more spacecraft leaving the solar system. NASA has asked Dr. Sagan to choose and assemble "The Sounds of Earth," an audio information capsule, in the form of two 33 rpm recordings, that will carry us and our cultures (one hopes) into some unimaginable future where some as yet unknown intelligence will hear it (unless, of course, they have only 45 rpm) and know what we are like. The records will contain not only greetings in some 60 languages, but also nonmusical sounds - surf, a baby crying, animal noises, sounds of our industrial civilization - and an hour and a half of what Sagan calls "exquisite music" - western, nonwestern, ethnic music of all kinds, including one as yet unchosen selection of rock and roll. The recording will be completed in August, and there may even be a commercial version available for purchase by you and me.

Also, Dr. Sagan is worrying at present about appropriations for the Jupiter Orbiter with probe, presently before Congress. What does he feel is our chance of contacting extra-terrestrial intelligences in our own life time? "If we proceed at our present pace, close to zero. We have to make a major effort if we expect to have a major chance at success. What is clearly needed is a dedicated facility. It's now done on essentially stolen time."

But will there be one more book by the author of The Dragons of Eden and 13 other books? Oh, yes, it's just about finished and Random House will probably bring it out next year. "It's a collection of essays . . . I hope very accessible, at least more so than Dragon. Some of them are very light, and one of them is about my impressions as an astronomer of the Miss Universe contest." And of course all of these activities are only sidelines to the main and most important activity of all: serious scientific research.