The Library of Congress is the ultimate library: it houses the world's largest collection of books, an assemblage stacked along more than 325 miles of shelves and indexed in 20,000 card catalogue drawers. It is, however, far more than a repository of books -- the Library of Congress claims among the "other" objects in its collections presidential papers, maps, Stradivarius violins, the letters of Sigmund Freud, motion pictures and the contents of Lincoln's pockets on the night he died.

Some of the library's divisions have acquired their own popular followings in recent years, especially the genealogy in recent years, especially the genealogy room. Although most family history research is conducted at the National Archives down the street, the library does have a comprehensive collection of local and family histories and reference guides to tracing family lineage and coats of arms. Free pamphlets help to sort out the various genealogical research tools.

In addition to sharing its resources with researchers, the library has been delving into its collections to find thimgs that can be reproduced and marketed as gift items at its own gift shop, curiously called the Information Counter.

The library's Recording Lab has produced more than 80 recordings of American and international folk music and tales, from American Indian chants to the music of Morocco. Many were recorded during field trips by members of the library's Archive of Folk Song. More than 35 albums of English and Spanish poetry, often recorded by the poets themselves, are also available from the Information Counter (most are $6.50 each). Recordings can be auditioned in the Music Division reading room before being bought. For a fee, the library will tape-record any record in tis collections (with permission of the copyright holders) for personal or research use.

The two-thirds of the Gutenberg Mible that aren't displayed in the Great Hall of the Library of Congress are ensconced in the Rare Book and Special Collections Division. A reproduction of the bible's opening page, along with an explanation of how the library acquired it, is available at the Information Counter for $1.75.

The maps and atlases in the library's Geography and Map Division (located at 845 S. Pickett St., Alexandria) span five centuries of cartography and depict everything from counties to continents. A facsimile of John Smith's map of Virginia, published in 1612 and decorated in the margins with drawings of Indians, coats of arms and a sea monster, costs $1.75.

Rare glimpses of America and the world are captured in more than 10 million prints, photos, negatives, posters, engravings, woodcuts, lithographs and architectural renderings on file in the Prinst and Photographs Division. Many of the designs on the 62 greeting cards sold at the Information Counter are derived from engravings and prints in this division. The library's Photodu-plication Service can duplicate photographs from this collection (again with permission of the copyright holder), the most popular being the well known photographic chronicle of the Depression taken by the Farm Security Administration and pictures of the Civil War. The Photoduplication Service also handles requests for photocopies of some of the 1,500 domestic and foreign newspapers and 70,000 periodicals to which the library subscribes. They've even been known to make copies of the front pages of newspapers for people who wonder what other earthshaking events took place on the day they were born.

The Information Counter also stocks things like tote bags emblazoned with the library's logo, calendars, posters, two popular 19th-century games, and a scarf printed with the Reward of Merit given to oustanding stoudents in colonial days. Next to the Information Counter and down the stairs from the ornate Italian-Renaissance archways of the Great Hall is an exhibition area where an entertaining view of Mickey emouse's 50 years of enteraining, accented with vidotapes of his best cartoons, is on display through February. An appealing color poster ( $3) and a catalogue accompany the exhibit.

Two other services offered by the library are worth mentioning -- and are free. For 45 years the National Library Service for the Blind and Physically Handicapped has been providing free briaille and recored books and magazines (and equipment and supplies) to anyone who cannot hold, handle or read conventional printed material. The library's American Flklife Center records American folk traditions through regular field studies of various ethnic groups and shares its discoveries in a free newsletter and free spring and summer concerts outside the library on the plaza.