by Harper & Row, $25.00. As paper pack rats, the Byron tribe rivaled the Adamses, and the mass of documents they accumulated has kept Ms. Moore busy for years. She has now reached Byron’s daughter, who had some reputation as a mathematician (how well deserved is not clear), got into trouble with racing debts, probably carried on a love affair with a worthless young cad, certainly appreciated the merits of a primordial computer, and died young and horribly of cancer. But since Ada and her well-meaning but weak-kneed husband never escaped from the control of Lady Byron, this volume is less a biography of Ada than it is the study of a family dominated by a rich, stingy, bullying neurotic. Lady Byron was a dreadful woman, and Ms. Moore, after disentangling all the old lies and lawsuits, hates her with a passion that fairly makes the pages sizzle. It also makes fascinating reading. Illustrations, appendices, index.. Langley Moore.