A Musty Old Book We Just Couldn't Part With

'I'm sending you something,'' my father says to me on the phone, in a voice as soft as it is secret. He won't tell me what it is. In fact, he won't say any more at all, except to offer me an invitation to find out how much whatever he is sending is worth. ''Probably not much,'' he concludes, ''but you never know.''

The package comes by mail a few days later. I'd been expecting one of those yellow post-office notices, asking me to come pick up something too bulky for the mailman to carry. But, no, it's small and light enough, book size. And that's what it is - a book: Carleton's illustrated edition of ''David Copperfield.'' ''Charles Dickens' Works,'' it says proudly.

The book is bound in a green cloth cover, torn slightly at the top of the binding, with a strip that's come loose and is unraveling, just above the gilded bust of Dickens. The bottom of the binding, too, has a frayed look. The print on the cover is green. Green letters highlighting a green background.

Date of publication: MDCCCLXXIV. It takes me a moment or two to come up with 1874, over 120 years ago and, it turns out, a mere 25 years after Dickens wrote the book in installments. Length: 821 pages including the handful of pictures. Price: $1.50. Inside the front cover, written hastily by hand, is our family name.

Would I sell such a prize, a distinctly autobiographical book Dickens once called the ''favorite child'' of his imagination, and surely a family heirloom of ours, its value to me and mine immeasurable? Of course not. And yet, my father will ask; so before I call to thank him, I do a bit of first-hand research. Bookstores may be closing left and right these days, but I still know a few that specialize in rare books. I wonder what the experts will say.

''No retail value at all,'' I learn at my first stop. The proprietor's hesitant to even touch the book; I'm not sure why. He's a man about my age, wearing a ''Bullwinkle'' the moose T-shirt and jeans. ''It's not a first edition, that's clear. If you had the whole set....'' He shrugs. ''Sorry, as is, it's not worth much.''

At my second stop - more of the same.

''It's not even in good condition,'' the young woman behind the counter observes. I like how the shelves of her store - crammed with books, many good ones I'm sure - are arranged honeycomb fashion. She, too, thinks my sole purpose is to make a profit, an understandable mistake on her part, given that I've said nothing to the contrary. It's fact-finding I'm after, or so I keep telling myself.

One last try. Similar results? Yes and no.

''Couldn't give you anything for it,'' an elderly gent tells me, holding the book up to his nose and smiling. ''But why would you sell it? It's probably been in your family for years, am I right? Smells a lot like my own books; adds to the pleasure of reading. Have you read 'David Copperfield'? Good. When was the last time?''

I admit it was a long time ago.

''Worth reading again?'' he asks.

''Sure.''

''There you have it.''

I'm certain my father will be pleased, and he is, laughing over the phone when I relate my encounters with the rare-book establishment. Dad surprises me by saying, ''I had the book checked out myself before I sent it along. Heard some of the same nonsense.''

But where did he get the book?

''It came from your grandmother's attic, like a lot of other fine and wonderful things,'' he tells me. ''I thought you knew.''

''I guessed - by the smell.''

''A sure giveaway,'' he says happily. ''Do you know, I looked it up, the book's original name, printed in one volume in 1850 or so, was.... Wait a minute, let me get it. Here. 'The Personal History of David Copperfield, the Younger ... of Blunderstone Rookery, Which He Never Meant to Have Published on Any Account.' What do you make of that?''

''You missed your calling, Dad. You should have been a historian.''

''Happy reading,'' he says.