It is fair that one measure a poet by what he had said poetry should be. Perhaps it is the only fair way. In Half Remembered , his candid and cathartic "personal history" published in 1973 when he was 45, Peter Davison wrote, "A writer may traverse his apprentice period and enter his years of promise, but until he has dealt, directly or indirectly, with the unique and ineluctable materials of his own life, he is unlikely ever to achieve maturity as a writer." He counted his own father a failure as a poet because "his poetry was an exaltation rather than a fathoming." Davison himself turned to poetry rather late in life, as poets go - at the age of 30. Walking the Boundaries, Poems 1957-1974 proffered fathoming in poetry true as sterling. Now past 40, Davison, the director of the Atlantic Monthly Press and poetry editor of The Atlantic has quite evidently matured and turne dto exaltation.

A Voice in the Mountain is poetry laid on far more diverse a landscape than Boundaries . Like the aborigines in "House Holding" of this volume, he has "moved on to gentler hunting grounds," having his earlier work "hung a gift from a branch to placate spirits."

A substantial portion of this work is homage to Robert Frost, whom Davison called the greatest of his teachers. After evenings with Frost, Davison "fell into my bed to ruminate on the movements of his speech, the ebullience of his words, the wittiness and singularity of his cadeness." It shows. The third of this volume captioned "Making Much of Orioles" might well be called "North of North of Boston." Davison, like Frost, writes with the hand of a farmer who has a hired hand to plow and harvest but who splits the wood himself.

One could do worse. (Atheneum, paperback, $4.95)

- Allan, A. Ryan Jr.