Straddled along the Mason-Dixon line, half of the town of Runnymeade is in Maryland, half in Pennsylvania; the local Husenmeir sisters, Julia and Louise (""Juts"" and ""Wheezie"") have temperaments that echo the geographical division, Julia is free-wheeling and let-live, Louise starchier and more pious. Pressed together into a decorum-destroying unit, though, they're a good deal of fun: adventure by adventure, they thread their way through the century from 1911 on in this jaunty scrapbook saga. Rita Mae Brown (Rubyfruit Jungle) has got her mostly female characters beautifully and high-spiritedly trained; when history nicks them, they slap right back. There's Celeste Chalfonte, Runnymeade's reigning heiress and Sapphist, who without much ado dispatches the local munitions tycoon, Brutus Rife, with a bullet through his brow. There's Fannie Jump Creighton, who responds to the Great Crash and Prohibition by turning her manse into a speak-easy. And there are at least half a dozen more--high-steppers to Brown's clearly feminist but always champagney and happy music. Though the march through time gets a little forced at times, Brown is always ready to bring us back to Runnymeade and its pranks: a for-money Monopoly game, for instance, that takes on the lineaments of a major social occasion. At her winning, fondest best, Brown has some of the same effervescent yet secure trust in her local characters that Eudora Welty feels for hers. Girls are more fun, seems to be the message; on the evidence of these here--no argument.