"It amazes me. I can't believe it!" says May Sarton. "I think of people of 73 as quite old. And I think, but I'm 73!"

Even her companions -- a cat, Bramble, and a sheltie, Tamas -- are, relatively speaking, in their senior years. She worries more about their deaths than her own: "When the cat was so sick, I really went into a tailspin. I thought, you know, first Bramble will go, then Tamas, and then I, because we are a very closely knit little family."

Sarton, author of 42 novels, journals, memoirs and books of poetry, will give a sold-out reading in Washington today as part of the Smithsonian's Resident Associate Program. Her appearance coincides with the publication of her most recent novel, "The Magnificent Spinster," a fictional biography of her great friend and seventh-grade teacher, Anne Thorp.

She forgets names. But she always has.

And she has a stoop -- but, she says, moving about briskly in her kitchen, "I've always had bad posture. I just say to myself, 'Straighten up, Sarton!' " Upon which, she vigorously pulls her body up to the fullest of its medium height.

"I don't seem old, do I?" she asks, more out of curiosity than a need for reassurance. In fact, she "loves" -- emphatically loves -- her age. She always thought she would, and she eagerly pursues the subject -- in her writing and in conversation. "Partly, you are more in control of your life . . . There is much less anguish and self-doubt. You are much more able to function freely and spontaneously, as yourself."

May Sarton lives a carefully protected life in the secluded coastal outskirts of a small Maine village. A visitor drives through twists and turns on dark, tree-flanked roads, eventually breaking out by a wide stretch of windswept sea, a shaggy meadow and Sarton's yellow clapboard house.

The house is a repository of keepsakes and treasures -- all remembrances of connections, past and present. To wander from library to living room to family room is to witness the extraordinary correspondence between the writer's work and her world. From the heavy, European farm-style furniture inherited from her parents to the stuffed toy animals that overpopulate the chairs and the sofas, the rooms and their belongings inspire a feeling of de'ja vu. Any Sarton reader has been there before.

"I love order," she says. On her bookshelves volumes are sorted into compatible clusters. Copies of her own works occupy one central shelf; nearby are neat rows of Virginia Woolf's novels, letters and journals, and of Elizabeth Bowen's books. Both are women Sarton knew in her youth. Farther from the center, apparently less primary in her life, are smaller collections: some Sylvia Townsend Warner, Colette, Flannery O'Connor, Anne Tyler, Vita Sackville-West. Outermost, atop a row of other well-worn volumes, lies a partially read paperback edition of Carolyn Chute's "The Beans of Egypt, Maine."

Vases of tastefully arranged fresh flowers -- purple asters, lilies and chrysanthemums, the bounty of her garden -- inhabit the rooms. The formal lines of the house, the symmetry of the flowers and the neatly arranged books assert the artist's passion for nature, form and order. But the order is carefully poised over a fault line of chaos. A desk drawer opens up to a clutter of trinkets, papers and miscellany. The kitchen counters are submerged under a layer of pots and pans.

In her journal "At Seventy," Sarton says that writing "is a way of understanding what is happening to me, of thinking hard things out." The keeping of a journal (something that she does deliberately for publication) is prompted, she says, by the "need to rediscover my life and its meaning."

Her struggles are old ones. As seemingly straightforward a task as answering letters reflects her lifelong effort to balance needs for human contact and solitary reflection. In her 1973 "Journal of a Solitude," she chronicled a year of deliberate withdrawal to the village of Nelson, N.H., where she fought the same demons she fights now:

I write too many letters and too few poems. It may be outwardly silent here but in the back of my mind is a clamor of human voices, too many needs, hopes, fears. I hardly ever sit still without being haunted by the "undone" and the "unsent." I often feel exhausted, but it is not my work that tires (work is a rest); it is the effort of pushing away the lives and needs of others before I can come to the work with any freshness.

She complains about the letters on the phone, in print and to the occasional visitor. Every writer gets them. But Sarton -- who has weathered the tempests of love and anger, recovered from cancer and a mastectomy, confronted the approach of old age and death, and written very personally about it all -- has made her life accessible in a way that elicits emotional responses.

"At one point, I said I will answer only letters from people under 10 and over 90. I don't answer them all. I can't. There are too many." She estimates that she has answered 2,500 since February.

Her lament, however, swings easily into exultation: "I have a wonderful correspondent now in San Francisco who is 80 years old and who said -- this is typical of the kind of letter I get -- 'I think I am enjoying you more now than I would have when I was 70.' This is so sweet! That at 80 he becomes a Sarton fan! I usually answer very briefly because I don't want to get into a correspondence, but this man interests me, and I'll see him when I am out there."

Why do readers respond so strongly to her writing? "In the end," Sarton suggests, "what a writer communicates is a vision of life. With so much that is depressing and agonizing around us these days, I feel sorry for the young. It's a terrible world to be in. Therefore, somebody who can make them feel that life is worth living -- just life in the sense of looking at the flowers or going out for a walk with your dog -- this is to be treasured. There aren't many writers who do this, there really aren't."

Virginia Woolf, whom she first met in 1937, was one. ("A pale pretty Shelley imitation American girl," Woolf wrote of Sarton, "who sat on the floor at my feet . . . ") "Now there you have a vision of life! . . . When one goes back to read her, it is heaven to be in that vision of life again. I think it is rather rare.

"I mean, what's Norman Mailer's vision of life? I haven't any idea! . . . Oh, yes, he's a good writer . . . "

Sarton began her quest for solitude in her mid-forties, when she felt that the demands of life were choking her creative self. "You don't have enough under your belt when you are under 30 to go and live alone somewhere," she says, cautioning the many young people who write declaring their identification with her choice. "I had had a very rich life when I went to Nelson. I had been in the theater [with Eva Le Gallienne's Civic Repertory Theatre], I had done movies during the war for OWI [Office of War Information], had done a great deal of teaching at Harvard and Wellesley, and had had a great many love affairs. When I went to live in the country alone, I went in sort of a despair that my work wasn't getting through.

"It was a tremendous adventure, of course. That's just what I needed, but I had so much inside me by then, where somebody of 19 just doesn't. You've got to have a job. I think before 30 you should find out how people live -- they have to earn their livings. I mean, you don't just sit in a cabin and write your soul!"

Sarton is proud that she got where she is without going to college. After high school she went directly into the theater. Although she had written poems from age 9 on, she spent six years as an actress before deciding that "writing was it."

Her family left Belgium in 1914, when Sarton was 2 years old; four years later her father was teaching history of science at Harvard University. "I was lucky not to be a Belgian poet," she reflects. "I would have been writing in a country divided between two languages, French and Flemish. That would have been awful. And then, English is a better language for poetry."

Her childhood and early adult life were punctuated by lengthy visits to England and Europe. Before World War II, in England, Sarton found herself as closely associated with a community of writers as she ever would be. "I have always been a loner. The nearest I came was in those years in England, when I knew Virginia Woolf, Elizabeth Bowen . . . all those people who were way ahead of me and who believed in me. It was wonderful. Then, I did know writers."

Now, however, Sarton does not seek the fellowship of her peers. "I think it's too competitive. Very painful. I don't belong anywhere. I went to Yaddo the writers' colony in Saratoga Springs, N.Y. , and I just hated it . . . I hated all the shop talk. I'd rather see people who are carpenters, who are sailors or who work in health departments, because then I feel I am learning something about life.

"With other writers, what is there to learn from them? Very little, now. I had everything to learn when I knew Virginia Woolf and Bowen. Now there is nobody I can learn from. I know that sounds arrogant, but I have written 42 books. Who is ahead of me now? I am at the top of the class."

Being at the top of the class does not, however, always mean being a bestselling author. But Norton, Sarton's publisher, ordered an initial printing of 40,000 copies of "The Magnificent Spinster" -- a high figure, she says, for "a writer like me," who has had "such bad luck with the reviewers" and is "nowhere with the literary establishment, even now."

Reviews are an inflammatory topic. The New York Times Book Review, she says, cast off "A Reckoning" (1978) as a lesbian novel. "I got cancer, I was so angry," she says. "I am sure it gave me cancer." That and an unhappy love affair she was having.

"My belief about cancer is that it is buried anger," she says through a cloud of her own cigarette smoke. "I saw that in my mother. I think she got cancer from buried anger against my father about money. It was a good marriage, but money was the sore thing in it."

Sarton thinks, however, that she has reached an age and a stature that should protect her from the harshest repercussions of intolerance. "I am not going to be attacked, probably, as I might have been if I were 40. I don't know. We'll see. I am not trying to get a job, for instance. I am established. I get honorary doctorates [12 in all] and nobody says, 'We don't give them to lesbians.' " She breaks into a mellow, alto laugh. There are advantages to being old.

She owns that she is "not as tense as I used to be . . . not as 'screwed up' towards doing something. I think I have less anger, though I can still get good and hot" -- about subjects as various as Ronald Reagan and some uninvited marauders at the two bird feeders outside her house.

Sarton eats her meals near a large picture window in the family room, which gives her a commanding view of the finches, grosbeaks, blue jays and dozens of other birds that flock to the feeders outside. At lunch, she repeatedly jumps up from the table, shoots across the room, disappears and can be seen, seconds later, through the window, flailing her arms. Projecting her actress' voice, she fires out stunning imperatives: "GO! GO! GO! GO!" Two squirrels, one red and one gray, spring instantaneously off the bird feeders, through the air and into the trees. Sarton returns to the table, triumphant, waiting for an encore.

"I have less energy, but I don't feel old," she says. "If you live every moment with great intensity, and I really do, then naturally you are tired, at the end of an hour you are tired. An hour of conversation tires me. It wouldn't somebody who isn't there, most people are only half there most of the time."

All in all, and anger aside, Sarton says, "I am at a good point right now . . . In some ways I feel I have had my life so that it wouldn't be a tragedy if I were told 'You have six months to live.' Nobody wants to die. I wouldn't like it, but I would not feel, 'Oh, it isn't fair! I haven't done what I had in me to do!'

"I think I've done what I have in me to do. Maybe I'll have two or three more books, but if I don't it isn't fatal, because I have said what I have to say.

"I am more there in my work, perhaps, than I am any other way."