THE VANDERBILT ERA Profiles of a Gilded Era <i> by Louis Auchincloss (Collier: $8.95, illustrated) </i>

This informal history continues turn-of-the-century New York society feuds unto the fourth generation. Louis Auchincloss details the activities of minor Vanderbilt scions, but gives short shrift to their social rivals, including J.P. Morgan, Mamie Fish, Jay Gould and Caroline Astor (the Mrs. Astor). Andrew Carnegie, Hettie Green, August Belmont and “Diamond Jim” Brady are conspicuously absent. Auchincloss writes with a rare, old-fashioned elegance, but his descriptions of the gilt-edged follies of the ‘90s lack the anecdotal flair of Lucius Beebe’s “The Big Spenders.” The problem may be that he’s too close to his subject: The descendant of an old New York family, Auchincloss offers a behind-the-scenes look at the lives of the old rich and famous--after the servants have tidied up.