By Gary Jennings

Atheneum. 869 pp. $21.95

The Virginian Gary Jennings has demonstrated his talent for pleasant research and mini-series staging twice before with the popular "Aztec" (1980) and "The Journeyer" (1984). His new historical travelogue, "Spangle," offers the vehicle of a 19th-century traveling circus, Florian's Flourishing Florilegium of Wonders, which begins in tatters in Virginia hard upon that famous surrender at Appomattox Courthouse and churns on like a five-year bull market through backward America and civilized Europe (Firenze! Wien! Moskva!) until crashing in the Paris Commune of 1879.

Jennings writes a chatty, informed, medium-angle-camera story. The good are very good and giving too; the bad are merely weak or confused or, if inexplicable, then most likely doomed. The major characters are provided vivid leitmotifs -- maestro Florian is floridly sentimental; Confederate officer Zachary Edge is nobly sentimental; pink-tighted performer Clover Lee is aerobically sentimental.

The historical characters whom Florian's circus attracts are obedient of their cliche's -- Phil Sheridan's charger Winchester is Black Beauty; Baron James Rothschild supplies excellent champagne; King Emmanuel of Italy, Emperor Franz Joseph of Austria, Czar Alexander II of Russia and Louis Napoleon of France are rose-watered, manipulative, henpecked, futile and as bloated a gaggle of white regents as one could find outside an Evans and Novak show.

And the rubes -- those who stand wide-eyed as the big top rises and comes down -- are goony, eager, endlessly credulous and surely the happiest success of the book because often they are to be heard laughing.

Surprisingly, Jennings displays some unhappy opinions in the choices he makes with melodrama and fate. Does he believe that homosexuality always leads to ruin? Two beautiful red-haired aerialists, Pepper and Paprika, are charming show people until they are strangely pulled down, supposedly by their lesbian jealousy -- Pepper perishing when her hair is yanked out by the scalp during a suicidal ascent.

Also the kindly balloonist Jules Rouleau, a homosexual, is humiliated when the circus' aging vamp Sarah forces her way into his bed, begging him to satisfy her so she can be certain she is not falling for Pepper and Paprika.

And does Jennings believe that the Civil War was fought because the Union army liked plundering and murder? That there was no other issue? His black characters are uniformly ill-spoken and small-minded save for one teen-aged aerialist named Sunday Simms, whose goal in life is said to be seducing the heroic Confederate Edge.

More worrisome still, does Jennings believe that women in general are out of control? A cretinous confidence man named Fitzharris confides to the English beauty Autumn Auburn that her arrival has disoriented the circus: "Every female in the company seems to be suddenly in heat. And it's your fault. I don't know why it happens, but I've observed it everywhere I've seen. As soon as there's a striking new girl in town, so to speak, every other one starts stoking up her biological urges." Autumn objects. The man insists, with some choice racist remarks.

Why excuse this rot? It does not advance the story, qualify relationships, reveal anything historical. It is typical of the excrescence that lily-white editorial boards pass under the veil of historical romance -- caveat emptor.

Then again, Jennings' research does provide some breathtakingly antique Victorian notions of sexuality. An ideal female proportion is said to be measured by comparing the distance between a woman's nipple and collar bone with the distance between her two nipples; if they are identical she is perfect.

Gary Jennings is by far superior to his peers at historical romance, such as the deaf John Jakes, the dumb Janet Dailey, the blind Louis L'Amour. "Spangle" is easy, gin-sipping entertainment. If Jennings would apply the same care to his loose-mouthed inventions -- and his troubled prejudices -- that he does to his facts, he would get my PG-13 without distaste.

The reviewer's new novel, "The True Story of the Russian Moon Landing," will be published next year.