This column is the first in a monthly series devoted to good books of the past. Since William Caxton published the first book in English in 1475, some 20 or 30 million English-language works have appeared. Of these a few thousand are recognized classics, ranging from "The Canterbury Tales" (1478) to, say, "The Poetry of Robert Frost" (1969). They need no advertising. A few thousand more are current works of known merit. They, too, can look after themselves. But that leaves a large category of books just short of classic status that are known only to a lucky handful of readers. They may be 30 years old, or 300. Each month "Rediscoveries" will discuss one such book.

THE SEMI-ATTACHED COUPLE is the answer to a good many prayers. It is the book you go on to when you have run out of Jane Austen's novels. Since Austen wrote only six, people who love them run out rather quickly -- and then have to wait a few years until they can read them again. Meanwhile they could be reading Emily Eden.

Eden was born in 1797, one generation after Jane Austen, and one social class above her. Austen was upper middle-class, the daughter of a clergyman. Eden was upper-class, the daughter of Lord Auckland. She is more sentimental, more worldly, and less intelligent than Austen -- but she is just as witty, and almost as delightful.

The Semi-Attached Couple was written in the 1830s, while she was in India keeping house for her brother, the Governor-General. To amuse herself on hot afternoons in Caluctta, Eden Began to write a novel about love and politics among the English nobility. These were subjects she understood well. Her sister Eleanor had been the one great love of William Pitt, the earl's son who became prime minister of England at 24. Eleanor later became Countess of Buckinghamshire. She herself had a romantic attachment to the eldest son of another prime minister. The affair ended badly, and she had to go to France to recover. Loves like these appear constantly in The Semi-Attached Couple, but transformed, so that everything ends happily.

The book has a huge cast of characters. At the center are the semi-attached couple themselves: Lady Helen Beaufort, age 18, and her brand-new husband, the Marquess of Teviot. They are semi-attached because Lady Helen really wasn't ready to get married. She was swept off her feet by one of the greatest noblemen in England, and she quickly discovers that she would much rather be back in Eskdale Castle with her large and loving family. They are not always breathing passion, having fits of jealousy, turning icy with Byronic pride. The central plot of the book is Lady Helen's eventually falling in love with her own husband.

Around these two swirl dozens of other people. Lady Portmore, the heartless society flirt is there, trying to break up marriages, and especially Lord Teviot's. M. La Grange, the anglophile Frenchman is there, making jokes in a heavy accent and madly taking notes for the book he intends to write when he gets back to Paris. There are at least three other romances, two of which could be straight out of Pride and Prejudice. There is a splendid parliamentary election.

What makes the book such a delight is a combination of two things: Eden's steady flow of ironic wit, and her very un-ironic view of how nice it is to be young, rich, and handsome -- as so many people in the book are. (She has no doubts about the joys of being nobly born, either.)

For example, just before the Teviot wedding, two upper-middle class sisters named Sarah and Eliza Douglas are getting a look at Lady Helen's trousseau. "'Thirty morning gowns!' whispered Sarah as they went downstairs. t"The idea of a new gown every day for a month! Now I call that real happiness.'"

Or their mother's comment, much later in the book, when her husband gets to talking politics -- in this case the politics of Spain and Portugal, troubled then as now.

"No, my dear Mr. Douglas, don't go off on those tiresome foreign affairs. What can it signify which conquers which, or who dethrones who, at that distance? Let them fight it out quietly. Besides, you need not pretend to understand national feuds if you have not found out what is passing under your eyes; but I cannot believe it, you must see what an unhappy couple these poor Teviots are!"

One could assemble 50 good quotes from Mrs. Douglas alone.

The book has it flaws, of course. With one or two exceptions, like Colonel Ernest Beaufort (age 26, and a London dandy), Eden does not draw male characters nearly as well as female ones. She has a habit, from which Jane Austen is quite free, of quoting bad romantic poetry at intense moments. jBut I will nonetheless confidently predict that almost anyone who picks up the book will be instantly drawn in. And on finishing it will be looking hopefully around for more. Should that happen to you, I have good news. Eden wrote a second novel, almost as good, called The Semi-Detached House.