Walter Cronkite is set to start work on his autobiography. "The deadline they've suggested at Knopf (his publisher) is spring of next year," says the semiretired anchorman, now promoting a coffee-table book on sailing. "But I don't know if I can deliver by then."

Once he gets started, Cronkite thinks the book might not take too long to write. "When I start something," he says, "I like to go at it full time without any interruptions. When I'm on a roll, I can work 20 hours straight."Cronkite also says he never understood why 1970s-era polls consistently ranked him the most trusted man in America. "I have no idea why that was, none at all. . . . I was just trying to tell people the news as simply and clearly as possible."