BRITISH COUNTRY HOUSES, reprise. Books at the Folger Shakespeare Library and architectural drawings at the Octagon Museum pick up the tune started at the National Gallery.

"The Compleat Gentleman: Books From English Country Houses," the exhibit at the Folger, describes in a hundred volumes the genteel way of life, from the 15th through the 19th centuries.

"Back when country houses were new, Henry Peacham wrote one of the early guides to manners and mores, and the most popular. Published in 1634, it was called "The Compleat Gentleman." Such a one was educated, athletic, interested in hunting and heraldry, and knowledgeable enough in the arts to be a proper patron.

Peacham recommended authors for the gentleman's library -- Spenser, Seneca, Cicero. Why, Lord Burghley of the Queen's privy council always carried a copy of Cicero, Peacham noted, "about him, either in his bosom or pocket."

In 1678, Jean Gailhard advised "The Compleat Gentleman" to travel abroad, for such travel brought men "out of their study and from amongst the dead to converse with the living." For this, "The Gentlemen's Pocket Companion for Travelling into Foreign Parts" was perfect company.

The gentlewoman's demeanor was not overlooked. In 1631, Richard Brathwait compiled a thin volume for Her, to accompany his guide for Him. Ideals for "The English Gentlewoman" were, as might be expected, "loving modesty," "virgin decency," and "apparell comely not gaudy." "Silence in a woman," noted Brathwait, "is a moving rhetoric."

The bare essentials of the palatial country houses where these gentlepersons lived can be seen in "The Architect and the British Country House, 1620-1920," at the Octagon Museum. Billed as the first such exhibit ever, it takes us from the 17th- century New Market Palace by the great Inigo Jones to Sir Edwin Lutyens' design for Castle Drogo, one of the last modern castles, completed in 1932.

The 90 drawings offer more than sufficient in the way of turrets and pillars, porticos and plinths, and ornate ceilings where nymphs dance in swirling tendrils of plaster.

The Victorian period does not fare well here. Regard for that architecture has crumbled rather like old castle walls. One drawing is cited in the show as "an example of the type of Victorian house that has so often been censured . . . Tudor Gothic, with hints of old English and early medieval in the tower." And another Victorian country home, Elvetham, is criticized for its "streaky bacon" style.

THE COMPLEAT GENTLEMAN: BOOKS FROM ENGLISH COUNTRY HOUSES -- At the Folger Shakespeare Library, 201 East Capitol St. SE, through April.

THE ARCHITECT & THE BRITISH COUNTRY HOUSE, 1620-1920 -- At the Octagon Museum, 1799 New York Ave. NW, through April 6.