Going Tubing In These Lazy, Hazy Days, Tv Can Be A Sorry Escape. But The Determined May Find Refreshment On The Schedule - Even (we Can Dream) A New ``seinfeld.''

Long, long ago, back before Web TV and Friends; the Game Show Network and picture-within-picture; Sony Watchmen and Jenny McCarthy; back before the first Mary Tyler Moore reunion show, the deities of television decreed the 39-week year.

Never mind that most mortals subscribed to a thing called ``summer'' that quaintly stretched the year by 13 weeks. There were vacations to be taken in TV-land, Riviera villas to be used, golf habits to be supported.

Summer on TV, then, especially the second-half ``dog days,'' has long been left for the reruns, the faint hopes, the completely escapist, and the absolute trash. Occasionally, categories have been combined (e.g. absolute trash disguised as a rerun). For a number of years, for instance, the networks would give people whose names started with ``K'' a summer variety show, to wit: The Keefe Brasselle Show (CBS, 1963); The Ken Berry ``Wow'' Show (ABC, 1972); The Kelly Monteith Show (CBS, 1976); The Keane Brothers Show (CBS, 1977); and, in a stretch, The Kraft Music Hall Presents the Des O'Connor Show (NBC, 1970 and 1971).

The late-summer fare on TV this year runs from the marginally educational to the miserably mundane; the passably escapist to the why-did-we-waste-a-nanosecond glop. There is probably not a Seinfeld (which gained its first fame in the summer of 1990) among them, but we can always hope.

Historical - and certainly hysterical - series include The New Adventures of Robin Hood (10 p.m. Mondays on TNT), in its second season, and the new Roar (9 p.m. Mondays on Fox).

Robin Hood is pretty much a study in camp. But since most every movie made about Sherwood Forest's favorite son has been made campier and better, the TNT version has few original ideas.

Roar is nothing if not original, at least for network TV. It's about fifth-century Celts looking for a mystical Life Force.

Roar has all sorts of good escapist stuff, from Visigoths to sorcerers to enough busting bodices to make it a Druid Baywatch.

Over at CBS, they're trying your summer patience with something called Ordinary/Extraordinary (8 p.m. Fridays starting Aug. 1). John Schneider, the former heartthrob from The Dukes of Hazzard, and Leanza Cornett, Miss America 1992, will be hosting a cross between Real People and That's Incredible! Here's what's on tap: a Cook Islands kindergarten teacher who shucks coconuts with her teeth, a cat who drives a motorcycle, cobra dancers from Thailand, a 10-year-old quadruple amputee who plays baseball and soccer.