If, as Marietta Tree suggests in her foreword to these letters written when Mrs. Alsop was married to the late State Department adviser William Patten, this is significant social history--then what time's the revolution? Susan Mary, whose genealogy is detailed somewhere around her fifth or sixth letter, is am American bluestocking who has divided her time between Bar Harbor, Washington, London, Paris (where her first husband was stationed) and assorted watering holes of the rich and powerful. Her letters are newsy and gossipy as she expresses her opinions on the Resistance and rationing (you'll learn what delicacies were served at Claridge's and Maxim's in these hard times) and various French political figures as well as describing the latest styles from Reboux, Dior and Balmain. Susan Mary has luncheon with the Windsors (she doesn't mind when they drop her--everyone knows they're boors); tea with the Churchills (Winston chasing after Odette Pol Roger in his dotage); goes nightclubbing with Adlai Stevenson: vacations on the Niarchos yacht; and puts up in Bordeaux at the Rothschilds'. She didn't meet the Kennedys until much later, but that's sandwiched in here too. All this and much more of the beau monde flitting about is delivered up in the most exacerbated debutantese possible with Susan Mary the epitome of charm on all occasions--which is after all the raison d'etre of State Department hostesses.