By Michael Cunningham

Farrar Straus Giroux. 308 pp. $25

Michael Cunningham, for all his popularity as a novelist of straightforward emotion, seems to me to be at heart an experimental writer. I don't mean the word in the way it is often used in English departments, a cooked-up moniker for prose that makes no sense or matters deeply to anyone but its writer and a few wags hoping to be thought of as intelligent. I mean experimental in the best sense -- its original, scientific and heroic sense: endeavoring to enlarge human knowledge through the rigorous observation of a small number of changed variables. Each of Cunningham's books seems to have been conceived in the spirit of discovery, and each of them has grasped for something incrementally different from and larger than the last.

A Home at the End of the World (1990) was a moving, if small, portrait of family and gayness. In his next novel, the underappreciated Flesh and Blood (1995), Cunningham kept the family and the gayness, and the variable he changed was the scope; Flesh and Blood was a much bigger book, with more characters and more scenes, and spanning many more years. The result was a sometimes uneven ride but nonetheless a profound emotional involvement, the most satisfying of all literary pleasures. That is to say, I cried. Then, with his overappreciated The Hours (1998), he kept the larger cast of characters and the long span of years but added a literary figure, Virginia Woolf, and a strange, almost supernatural implication of reincarnation. The result for the reader was an eerie sense of deepened emotion and heightened significance, even if both were logically inexplicable, and the result for the writer was the Pulitzer Prize. Live and learn.

Now, in Specimen Days, his brilliant and imperfect new book (I loved it by the end but still wouldn't exactly call it a novel), Cunningham has taken what he learned from The Hours and conducted another experiment. This time he's used a similar triptych structure, a similar pervasive sense of reincarnation and a similar literary-figure cameo, but he's cast the novel wider, lumped it rather than shuffled it, and spread it over several centuries. Specimen Days is made up of three novellas so wildly different you'd never guess they were from the same book except for the fact that characters in them have the same names and carry around the same bits of crockery. They also recite bits from the same poet, Walt Whitman.

"In the Machine," which opens the book and is the weakest of the three sections, is the story of a destitute Irish boy working ghastly shifts in a Dickensian ironworks in 19th-century Manhattan, all the while obsessed with a forbidden love. Oddly, he finds himself quoting Whitman. "The Children's Crusade," which follows, and in which the book takes wing, is a more or less contemporary story of a black woman detective in New York City, trying to track down a group of next-generation suicide bombers who like to quote the great poet in their cryptic communiques. "Like Beauty," the last of the three, is a futuristic romp and love story, involving programmed semi-humans and their unusual, if still terribly touching, affairs of Platonic love. Oh yes, and everyone's quoting Whitman.

It's this last novella that showcases Cunningham's delightful brilliance. The setting is so far in the future that he can invent it almost entirely, giving loose rein to his playful genius for description, his gift for rollicking plot and a good joke and at the same time his lovely insistence on the tragedy that, in all his work, shadows desire.

I, for one, wish Whitman weren't a part of any of it, but that truly is not a major concern. The Whitman motif is just one aspect of Cunningham's brave experimentation, and even an experiment with an unwanted result can be a successful experiment. Cunningham, one hopes, has learned from it, or at least from the reaction to it, and I know other writers will as well. Readers and writers will also no doubt draw conclusions about the reincarnation motifs of both this book and The Hours, about how the repetition of names and themes over several generations lends them peculiar and inexplicable weight, or perhaps how such repetitions are merely literary trickery.

For now, Specimen Days offers just about every kind of literary pleasure, and all of them in abundance: suspense, hilarity, invention, romance and passage after passage of breathtaking prose. As one of his characters passes by a shop window, Cunningham writes, "A woman sat at the rear, behind a glass counter. She was as wan and worn-looking as her merchandise. Her gray hair hung to her shoulders, and her face was vague, as if someone had drawn the features of a woman onto the front of her head and then tried to erase them. Still, she was queenly, in her ruined way. She sat erect, with a vase full of peacock feathers on her right and an oval mirror on her left, like a minor queen of the underworld, ruler of the lost and inconsequential." By its quietly tragic end, the reader, like several of the characters, has gone heavenward.

It's this sense of tragedy, in fact, quietly thrumming below the racket of nuclear Winnebagos and Whitman-ejaculating memory chips, that sets this far-ranging adventure squarely in the realm of Cunningham's other painfully felt novels. The structure of Specimen Days is experimental, its plots are bizarre, and one character is literally poikilothermic, but at the same time the book concerns itself with what all his books have: human connection among misfits of every ilk, our constant pain of loss, and our equally constant striving for solace. *

Ethan Canin is the author of five books of fiction, including "Emperor of the Air," "The Palace Thief" and "Carry Me Across the Water."

Michael Cunningham