As a bookseller, I probably shouldn’t tell you about this, but since it is likely that you are a serious reader, you ought to know about the Mercantile Library if it has somehow escaped your notice.

This terrific institution comes to mind because it has the largest circulating collection of mystery fiction in the country, and has just received a grant from the National Endowment for the Arts to host a Big Read celebration for “The Maltese Falcon,” one of the 16 great books chosen for this event in the first half of 2008.

The Merc — as we cool, in-the-know professionals call it — is a private library established in 1820, before there were public libraries. It was, and is, dedicated to disseminating literature to those who were not wealthy enough to build their own libraries, and it has amassed an enormous collection of fiction, with special emphasis on the most popular of all genres: mysteries. For a modest annual fee, members can check out everything from current best sellers to the most obscure works of authors who are rarely read today, as so many were in their own lifetime. It is located in a beautiful but non-intimidating building at 17 E. 47th St.

The Big Read, co-sponsored by the Merc, the Mystery Writers of America, the Grand Central Partnership, and the USO, will stage a series of events during April dedicated to Dashiell Hammett’s iconic detective story.

The entire schedule of events has not yet been finalized, but among the activities that should appeal to anyone who is an aficionado of this outstanding novel, or mystery fiction in general, are a panel called “Tough Gals: The Influence of Sam Spade on the Contemporary Female Detective” (April 8); reading groups where everyone gets to participate, or not, if they prefer (April 10 and 17); a panel titled “Books into Film” (April 15); a walking tour of locations important to Hammett (as well as to Nick and Nora Charles), including the 21 Club, the Plaza, the offices of Hammett’s publisher, Alfred A. Knopf, and Black Mask Magazine (April 19), and a live performance of a Hammett short story in the style of a 1930s radio program (April 29) , recorded by the new Black Mask audio magazine.

Off-site, there will be a kickoff party (oddly, on April 9, the second week of the Big Read) at the Commerce Bank (317 Madison Ave. at 42nd Street), and a special screening of the perfect hard-boiled private eye movie, starring Humphrey Bogart (Sam Spade), Mary Astor (Brigid O’Shaughnessy), Sydney Greenstreet (Casper Gutman, the Fat Man), Peter Lorre (Joel Cairo), and Elisha Cook Jr. (Wilmer, the gunsel). It will be shown in the magnificent Campbell Apartment in Grand Central Station (April 12).

And there’s more. Check the Merc’s Web site, www.mercantilelibrary.org, or call the friendly folks there at 212-755-6710 for times, reservations, etc. This terrific program is the stuff that dreams are made of. It’s why you live in New York, not Toledo.

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If you have ever read and enjoyed a book by Dick Francis (and, let’s face it, if you read one, of course you enjoyed it), you might like to have a good thought for him, as he’s a very good man who’s had a very bad year, with a string of worrisome health problems.

The latest report is that this tough old former jockey is coming around and will have a new book, co-authored with his son, Felix, published in October. There may be a writer who is kinder, humbler, and more decent than Dick Francis, but I have yet to meet him.

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One of the many elements that recommends classic detective fiction is that it has a moral basis; it illustrates and celebrates the difference between good and evil, usually allowing good to emerge triumphant. Loren D. Estleman’s P.I., Amos Walker, has this to say in his 1981 novel “Angel Eyes”: “A private detective with a code may be nothing more than a pebble on the beach, but at least he stands out from the grains of sand.”

Mr. Penzler is the proprietor of the Mysterious Bookshop in Manhattan, and the series editor of the annual “Best American Mystery Stories.” He can be reached at ottopenzler@mysteriousbookshop.com.