The signs are everywhere, from the summer’s sleeper movie hit, “Sleepless in Seattle,” to Gap ads (brooding people in shots so dark you can’t even see the clothes). Bloody-minded movie director Martin Scorsese has fallen into step with “The Age of Innocence,” a period love story starring Daniel Day-Lewis (who, fresh from the even more lushly romantic “The Last of the Mohicans,” is the hands-down favorite as the trend’s poster boy). Romance, a literary mainstay, is as hot as ever. Romance novels now account for 40 percent of all paperbacks sold. Even the incontestably literary Cormac McCarthy’s “All the Pretty Horses” is, at heart, a cowboy romance. For literary love with a twist, there’s Nick Bantock’s lavishly illustrated trilogy of epistolary novels about lovers Griffin and Sabine. And next spring cable television will get its first channel devoted to showing nothing but romantic movies.

If romance is a growth industry, then Robert James Waller is surely the General Motors of love. In July he released a CD, “The Ballads of Madison County” (though it fared about as well as the Vega), and starred in the video. Next year Warner, which has him signed for at least two more novels, will release a collection of his essays and a book of his photographs (mostly of–what else?–bridges). Meanwhile, rumors are flying around Hollywood about who–from Robert Redford to Clint Eastwood–will play the handsomely weathered leading man in the movie of “Bridges,” which Steven Spielberg will direct.

Can Waller succeed with “Waltz” as amazingly as he did with “Bridges”? Warner is betting yes with a first printing of 1.5 million copies. And no one is worried about reviews. “Bridges” got lukewarm notices at best and sold on bookseller enthusiasm and word of mouth, leaving Warner president Laurence Kirshbaum to crow, “We are dedicated to publishing review-proof books.” Irwyn Applebaum, president and publisher of Bantam Books, agrees that lightning could easily strike twice for Waller. Noting that romance novels have become “one of the most active areas of general fiction,” with sales hitting $750 million a year, Applebaum thinks “Bridges” was just the “tip of the iceberg.”

Certainly Waller hasn’t toyed much with the formula that propelled him to success. Like “Bridges,” the new novel describes an adulterous affair between two middle-aged people. As before, the woman is married to a clod. And again, the hero, who hogs the spotlight, is a loner, a prickly individualist. “People saw him as distant, and he was. People saw him as arrogant, but he wasn’t, quite the opposite,” he writes in “Slow Waltz.” In “Bridges,” Robert Kincaid was a Camel-smoking vegetarian freelance photographer in a pickup truck. In “Waltz,” Michael Tillman is a Merit-smoking professor who keeps a Vincent Black Shadow motorcycle in the living room of his apartment. Both men are the sort “that seems ill designed for the world in which they live.”

More happens in “Waltz”–the characters travel from Iowa to India–but both books are curiously static, more situations than stories. Kathleen Kennedy, a producer at Steven Spielberg’s Amblin Entertainment, admits that one of the stumbling blocks with turning “Bridges” into a movie is the lack of action. Kincaid and Tillman don’t talk, they preach, and the rest of Waller’s prose reads an awful lot like highclass ad copy (box), raising the suspicion that he isn’t as interested in telling a romantic story as he is in selling the idea of romance.

The big difference in the two novels is their endings. In “Bridges” the lovers part, and the reader has vicariously enjoyed an affair where no one is punished–and family values win out. You put the book down convinced that your perfect lover is out there somewhere, and in the meantime you get points for sticking with your mundane partner. “Bridges’s” aborted love affair is smack in the middle of the trend, too: in “AU the Pretty Horses,” “The Age of Innocence” and Merchant-Ivory’s forthcoming “The Remains of the Day,” the lovers don’t stay together, if they even get together. It’s a perfect strategy for these slow-to-commit times. In “Slow Waltz,” Waller contrives a more Hollywood happy ending, but there’s no sizzle or satisfaction. There’s just the lingering conviction that Waller’s not a waltzer, he’s a clogger.

Robert Waller writes fiction. J. Peterman writes mail-order-catalog copy. Both sell romance. See if you can tell the difference.

Paula V. (I learned her name later) was from Finland, lived in Paris, spoke hoarse beautiful French, designed clothes (always had, since age 11), was tall, taut, full of energy…wonderful to look at, black-eyed, blonde, divorced.

FROM THE J. PETERMAN CATALOG

It was all there. The cool patrician face coming only from an upper-shelf gene pool, the night-black hair …A body the old French called rondeur…Gray eyes coming at you like an arrow in flight and a confidence with men indicating she knew what they could and could not do.

FROM “SLOW WALTZ IN CEDAR BEND”