ON the fourth day of her residence in the White House in 1800 Mrs. John Adams “jounced in her carriage to Georgetown to return fifteen calls. Such was the social pace. That phase has never stopped.” Mr. Hurd more than proves this in his gossipy history of Washington Society, written with affection and a phenomenal attention to detail. The Cavalcade includes the hostesses (and what they wore), the dinner parties (who sat where and what they ate), the fends, the petticoats in politics, the diplomatic corps, the gold braid, the typewriter statesmen — and the statesmen themselves, from John Adams to Jimmy Byrnes. This kind of book can be fatuous or fascinating. Mr. Hurd, who is neither a snob nor a scandalmonger, is never fatuous. How fascinating you find Washington Cavalcade will depend largely on your interest in the subject.