Tides may turn and rivers may flow and storm clouds may gather and saps may rise but through it all, the rich live well. Very well. Oh very well indeed, as evidenced in the sumptuous and stately three-part public TV series "Treasure Houses of Britain," which began last week with "Building for Eternity" and continues tonight at 10 on Channels 26 and 32 with "Palaces of Reason and Delight."

It was the Age of Reason, but 18th-century lords and ladies were surely not total strangers to delight. Or so the host and coauthor of the program, John Julius Norwich ("the Viscount Norwich"), discovers while burrowing among underground caverns where members of a blue-blooded ensemble known as the Hellfire Club practiced, says Norwich, "all kinds of sexual hanky-panky" and didn't let the subterranean chill dampen the ardor of their orgies.

A descendant of one of the group's members recalls, in fact, that they were capable of "all sorts of monkey tricks," apparently literally, for there was that "famous baboon incident" in which said species of primate allegedly leaped upon Lord Sandwich in the abbey. Such scandalous tales are of course not the principal thrust of "Treasure Houses," but they do make a nice respite from the frescoes and the friezes and the furniture. A huddled chorus of antique chairs in Houghton Hall may still boast "the original gilt," as Norwich says, but that has nothing much to do with original sin.

One could find the splendors spread out in "Treasure Houses" sinful, on the grounds that not even the rich should ever have lived quite this well, but the tone and the tenor of this series are such that you never really begrudge the wealthy their wealth, because if they hadn't built and preserved these magnificent places, they wouldn't be here for the public and the camera to roam through now. The word "decadent" somehow never quite springs to mind, not even when the aristocratic opulence reaches staggering proportions.

Norwich makes a program that is essentially about things also a program about the people who built and bought and horded those things, and his commentary is leavened with just enough musty gossip to keep it from being a lecture. There are references to the eldest "bastard son" of Charles II and the "wastrel grandson" of Robert Walpole and their effects on time and, more relevantly, place. Norwich wrote the effortlessly illuminating script with J.H. Plumb; the series was produced by Michael Gill, directed by Peter Newington and intimately yet respectfully photographed by Fred Tammes.

Among the stops on tonight's tour is Syon House in Middlesex -- once a prison, then a palace, now a setting for a cocktail party given by a duke's daughter and appreciatively attended by Norwich. Earlier he encounters the present Marquis of pronounced "Chumley," whose appearance certifies that yes, there are still such living creatures as a marquis of anything, much less Cholmondeley, and also includes a view of one of the largest collections of model soldiers in the world, all carefully arranged on pristine toy battlefields housed inside vast glass cases.

"This took a lot of setting up," the present marquis of Cholmondeley says.

At times the broadcast does seem to qualify for entry in the annals of "There'll Always Be an England."

But most of the time it is simply a great treat, especially for the eyes, but also for that part of the pleasure center that was touched and coddled by such imported British series as "Brideshead Revisited" and "The Jewel in the Crown." Ah, the faded gentry! Today's rich are irritating and yesterday's touching; why is that, I wonder?

The last chapter, next week, is called "Recapturing the Past," which is essentially the theme of the whole production. Made under the auspices of the National Gallery of Art, in conjunction with the "Treasure Houses" exhibit, and presented on PBS by Washington's WETA, this series about treasures is, when you get right down to it -- and you should -- treasure itself.