EVERY FORCE EVOLVES A FORM Twenty Essays by Guy Davenport North Point. 171 pp. $16.95 THE JULES VERNE STEAM BALLOON Nine Stories by Guy Davenport North Point. 160 pp. $21.95; paperback, $11.95

SCHOLAR, POET, translator, essayist and writer of hard to classify short fictions, Guy Davenport often seems an Alexandrian born out of time and place.

If this makes him somewhat anomalous it does not make him an anachronism. His classical scholarship, his knowledge of the old concept of the polis, for example, makes him an excellent guide to the development and decline of the American city. He points out that the idea that people migrating to the American West were always "pioneers clearing the wilderness for farms" is a myth: often as not "they were colonists who had the plans of cities in their heads, the first since Greeks and Romans to set out from mother cities (metropolites) to reproduce examples of the model they came from." The same long perspective enables him to recognize New York for what it is -- "our Alexandria, our Byzantium." He notices the resemblance between e.e. cummings' best poems and those of Archilochus, and his knowledge of the mimes of Herondas makes it possible for him to cast new light on Finnegans Wake: "We have yet, after all these years, to admit that the Wake belongs to the art of mime, to the most vulgar and riotous of the arts." And this, Davenport insists, is the key to its greatness.

The essays in Every Force Evolves a Form move with rare agility from Le'vi-Strauss to Pound or Proust or Plutarch; from painting by Rousseau to texts by Rimbaud, Flaubert and Apollinaire. His learning is impressive but is never a burden to the reader. He can be contentious and acerbic -- dismissing The New York Review of Books as "that bastion of gratuitous meanness" or describing Noah Webster "as Uriah Heep sniffing out naughty words in the Bible, deleting them, and congratulating himself on being more genteel than God" -- but he is also generous in his sympathy when limning brief sketches of Montaigne, Charles Wilson Peale (and all the other Peales), or that most genial of English wits and eccentrics, Sydney Smith. Davenport writes in a style that is consistently cultivated and vigorous, elegant and direct. There can be no doubt that, on this occasion, the various forces at work in his fertile mind have evolved the right forms.

The Jules Verne Steam Balloon is more problematic. Most of it is taken up by a linked sequence of long stories concerning the sexual awakenings of a group of adolescents in Denmark. Since the vast majority of the characters are male the stories tend to devolve into prolonged idylls of mutual masturbation. Tedium soon threatens but it is worth persevering, and, once again, it helps to regard these stories as Alexandrian. What could be more Hellenistic than romantic friendship between handsome ephebes? The problem lies in the fact that we no longer live in the age of Theocritus, and in our time it is difficult to present these couplings (and triplings) as natural, guiltless celebrations of Eros. Davenport's idyll lapses into sentimentality and his sexual vocabulary can be unbearably coy.

This coyness also invades what we might call the second, mythological plane on which these stories work. This is the plane of the Jules Verne steam balloon and its pilots Quark, Buckeye and Tumble. This trio of tiresome amoretti take the form of 10-year-old boys and turn out to be immortals sent by some vague, higher authority to watch over and advise favored mortals.

The chief focus of their attentions is Hugo Tvemunding, assistant classics master, gym-instructor and mentor to Kim, Andres, Franklin and all the other "golden lads" so busily playing with their erector sets (to allude to Nabokov). Hugo is writing a thesis on the survival of pagan elements in the gospels, particularly the concept of the daimon. Since it is only to Hugo that our three immortals manifest themselves we are obviously meant to conclude that they are the daimons he is writing about. In the most compelling scene in all four stories he expounds his thesis while Quark and Tumble gambol about the room, invisible to everyone but Hugo: "The whole crunch of theology . . . is to what extent do people imagine that creatures of another realm, higher or lower, or invisibly within ours, interact with our lives?" This, I take it, is also "the whole crunch" of this sequence of stories, but it is still unclear to me why immortals should be so interested in a tender-hearted gym-instructor and some randy teen-age boys.

IF THESE stories remain puzzling there can be no doubt about the value of the shorter pieces in this volume, especially "Pyrrhon of Elis," a masterly account of the life and beliefs of a skeptic philosopher whose "great teaching was that we should resist reality with all our might." So, we are informed in a magnificent final sentence lasting nearly a page, Pyrrhon lives most of his life in the charming town of Elis surrounded by all the color and diversity of the late Greek world, surrounded in short by "a fine round world of people and things, seasons and years and rumors of other worlds as far away as the Indus or the Nile, the Thames forever hidden by fog and the Danube said to be as blue as a Doric eye; but was honestly uncertain that he did, and would never admit to any of it."

At his best Davenport is one of the true poets of prose. "Pyrrhon of Elis" is also a reminder that his fictions should be read together with his essays. A question raised in an essay on Joyce: "What is the relationship between figure and ground?" has its echo in "Pyrrhon": "Everything is known as a figure in a ground or not at all." So Joyce turns out to have concerns in common with a philosopher who was a near contemporary of Alexander the Great, and though the axiom "Every force evolves a form" may sound like Heraclitus it was invented by Mother Ann Lee, the founder of the Shakers. :: John Ash's most recent book is the collection of poems, "Disbelief."