Dear Boy Writes Home From America : LETTERS FROM AMERICA<i> by Rupert Brooke, preface by Henry James (Beaufort Books: $16.95; 222 pp.) </i>

It’s 75 years since one personable 26-year-old paid North America a wide-eyed visit. American music had been giving Londoners “a very definite taste of a jerking, vital, bizarre, ‘rag-time’ civilization,” which Rupert Brooke proposed to see for himself. “My God!” was how most friends greeted the idea. “A country without conversation,” was someone’s warning. Somebody else did say, “It’s Hell but it’s fine.”

An American he met on the boat denied that any Englishman could understand America, where “one man’s just as good as another”; then as a special treat recited for him the Declaration of Independence. “This is some country!” another American said. A gone world, that world of 1913.

In New York that summer, Brooke noted what you’d expect, the melting-pot vitality, the babel of Yiddish, Italian, Greek, Polish, Russian that filled rush-hour trams, the skyscrapers, the huge electric signs promoting underwear. (Was there really so much push for underwear, or was Brooke just sensitized to it?) No differently does any American in London get enchanted by rolled umbrellas and square-block taxis.

In Boston, baseball proved exciting but unbeautiful except for “the long-limbed ‘pitcher,’ whose duty it is to hurl the ball rather further than the length of a cricket-pitch, as bewilderingly as possible. In his efforts to combine speed, mystery, and curve, he gets into attitudes of a very novel and fantastic, but quite obvious, beauty.” Yes, beauty meant a lot to Rupert Brooke, who’d once even felt “quite sick and faint with passion at the beauty of a painting by (Augustus) John.” Later in New York, he was enraptured by a huge electric sign for pepsin chewing gum.

And Brooke’s own beauty meant much to many in England, notably to Eddie (later Sir Edward) Marsh, private secretary to Winston Churchill, then first lord of the Admiralty. Here the plot commences to thicken. For Marsh plumed himself on connoisseurship of the poetic, and Brooke was a poet as much as he was anything. So after Sub-Lt. Brooke had died in 1915 of sunstroke and septicemia en route to the Dardanelles, Marsh set out to make secure for all time the literary renown of the “dear boy.”

“Collected Poems, with a Memoir by E. Marsh” was one stroke in that campaign. Another, these “Letters From America,” reprinted unpretentious impressions Brooke had sent to the Westminster Gazette.

Even Marsh seems to have sensed it was rather slight. To be an Event, it needed a Preface. And what more prestigious sponsor, in 1916, than the Great Internationalist himself, the circumlocutory expatriate Henry James? A decade before, James had published “The American Scene,” his own response to a New World awash in a new century. And his homeland’s detachment from the War for Civilization had so angered him that he had acquired British citizenship. And Marsh knew how to put on pressure.

Hence the spectacle of The Master, in the last months of his life, spinning with evident effort about 8,000 words around--he can never quite bring himself to say what. He mustn’t let down Eddie Marsh, or deny his own liking for the youth he’d met a few times. And a dead soldier-poet might lift the hearts of patriots.

But in none of these attractive directions could James quite let himself go. He deeply suspected that Brooke’s charm, both personal and poetic, would never have survived his ingenuous youngness: that Brooke as mature poet was inconceivable. Nor could he but regard with dismay one poem about being seasick. As for “Letters From America” itself, its author had, after all, seen little beyond the obvious. So wasn’t its modest claim on our attention reducible to youthful charm? Misgivings are audible, beating against opaque prose like bats at a shuttered window.

Not even with The Master’s sponsorship did the book make great stir in 1916 England. This spring, America finally gets to see it. Why? Hard to say. A slice of cake from a long-ago birthday party, it has the faint pathos of a souvenir. Some good descriptive pages on Niagara don’t balance the spectacle of Henry James embarrassing himself and his admirers.

Eddie Marsh? When he died in 1953, his attic contained a handkerchief from under the dying Brooke’s pillow, and some copies of a pamphlet called Sexual Ethics. But Brooke appears to have been heterosexual.