From a 1687 broadside, Mistress Puss, the "alomode" cat, haughtily stares down those who would criticize her topknot, a fan-shaped ribbon cluster with dangling lappets of lace -- a fashion among London ladies of the period.

This curl of culture, along with the first book on fencing published in the British Isles (Edinburgh, 1687); "Theatrum Machinarum Universale ...," a collection of engraved plates of staircases, printed in Amsterdam in 1739; and "A Book of Fruits and Flowers. Shewing the Nature and Use of Them, Either for Meat or Medicine" (London, 1653), are among the 100 or so rarities in the Folger Shakespeare Library's new exhibit.

The catches of the past five years are on display through March 17 in the Great Hall. They represent a small selection of the 45,000 or more books, manuscripts and objects bought in the past 40 years by Elizabeth Niemyer, the Folger's Louis B. Thalheimer curator of acquisitions.

Allow plenty of time -- the visitor will want to stop and read every label and decipher the writings. The variety of objects is notable.

Contrary to the opinion of all those who write in hoping to sell their grandfather's 19th-century copy of Shakespeare, the Henry Clay and Emily Folger collection of rare Shakespeareana -- the library's endowment at its founding in 1932 -- was so complete, Niemyer said, "that we really don't need to buy much more old Shakespeare." The Folger actually has the largest number of early editions of Shakespeare in the world.

What the Folger does covet is background material of the English Renaissance. Books from the 16th and 17th centuries on trade records, botany, horses, fashions, cooking and stranger subjects help explain allusions in Shakespeare and other writings of the times, and illuminate the period's common and court lives.

"Not just English works, but other countries' " said Niemyer. "We were glad to get 800 books and pamphlets on the German and Swiss Reformation. They came right from a bookshop where Erasmus's publisher had his press."

On display in the exhibit is the most important art acquisition ever for the Folger: a miniature tempera-on-vellum painting of Lettice Knollys, who shows a knowing look under her coronet and above her ruff. She was wife, in turn, to both Walter Devereaux, earl of Essex, and Robert Dudley, earl of Leicester. Queen Elizabeth I loathed her cousin Lettice but loved both one of her husbands and her son.

The original prompt copy with its performance license for "The Change of Crownes," a 1667 play by Edward Howard, is proudly shown as the "most significant manuscript acquisition in many years." Although the play was approved for performance, it offended King Charles II and was banned. For years the play was presumed lost, until it was found in a private collection in 1938.

An eerie feeling of the reality of Shakespeare's characters comes over the viewer of a vellum property transfer from Sir Henry Green to Sir William Bagot, two 14th-century figures who appear in "Richard II." Shakespeare called Bagot one of the "caterpillars of the commonwealth."

Costumes of Europe and Turkey in the 16th century, as seen in a book printed in Antwerp in 1588, the year when the English vanquished the Spanish Armada, are represented in a page showing four Tudor rulers.

Guidebooks go back further than the traveler might think. Shown in the exhibit is "A Vade Mecum for Malt-Worms; or, a Guide to Good-Fellows," with a verse (sometimes lewd) for each of the "most eminent publick houses in and about ... London and Westminister" (London, 1720).

Actor Raimond Poisson as Crispin, the French Scaramouche character, is shown in all of his sly charm in a 1682 Paris engraving. Edmund Kean, the actor noted for playing Richard III, is caricatured as fending off a nest of dragons in one 1824-1825 print. Its title, "The Hostile Press; and the Consequences of Crim. Con." (criminal conversation, the term then for adultery), suggests his notorious affair with Charlotte Cox.

On a recent tour of the rare book vaults, Niemyer proudly pointed to bay after bay of her prizes. (The climate-controlled treasure rooms are an achievement of the late O.B. Hardison's years as director of the Folger.) The Folger owns 280,000 books, 100,000 from before 1800.

Niemyer's predecessor almost a half-century ago spent half a year in London and on the continent, buying. Now, Niemyer goes over only for three weeks or so annually to remind collectors and booksellers of the Folger. The rest of the time, she hunts in catalogues.

"Now we can't afford to buy much at all, with the high prices of rare works. When I first came here, we bought 1,000 or 1,500 pieces a year, but in the 1980s, we've been lucky to afford 250 to 300. Prices have gone up amazingly." She cited the $10,000 sales price of a book on veterinary medicine. She bought a similar one for the Folger in 1960 for $40.

Niemyer is still trying for a book about the gardens of Heidelberg Palace made for Elizabeth, daughter of James I. After years of effort, she found a copy, but its owner likes it too.

The Japanese have entered the rare papers market now, Niemyer said, looking for information on Adam Smith, whose writings influenced their constitution -- and running up the price.

As for Niemyer's own tastes, she and her cat, called Daphne (and other things), collect rare books about felines in their one-bedroom apartment in Harbour Square. They have about 50 catworks, including one called "The War Between Dogs and Cats," and a 16th-century poem about a soldier and a cat. When Niemyer's not reading biographies of the descendants of Victoria, she reads Charlotte MacLeod and Elizabeth Peters/Barbara Michaels, whose mysteries abound in cats and other animals.

The handsome catalogue to "Five Years of Acquisitions" -- an edition limited to 750 copies -- is itself sure to be collected. Within the marbleized cover are color prints, an introduction by Niemyer and a foreword by Folger Director Werner Gundersheimer. The Folger is at 201 East Capitol St. The exhibit is open 10 a.m. to 4 p.m. Monday through Saturday.