The nation's television viewers apparently felt they needed a nice change from the war news and the shoot-'em-ups Sunday night and CBS and the Hallmark Hall of Fame series provided it with "Sarah, Plain and Tall" ...

The result was a ratings triumph for CBS. The touching story set in 1910 -- of a single woman from Maine (Glenn Close) who answers an ad for marriage from a widowed Kansas farmer (Christopher Walken) -- averaged a 25.2 rating and a 36 percent audience share in Nielsen's 25-city overnights ...

By comparison, "In Broad Daylight," an NBC movie based on a true story about small-town vigilante justice in Missouri, averaged a 13.4/19. And Part I of ABC's widely publicized (and reviewed) "Son of the Morning Star" -- the story of Gen. George Custer's brutal last years -- drew only an 11.5/16 during the same two hours in the 25 big cities ...

CBS, which hasn't had a lot to brag about for some time, said "Sarah" outperformed the first night's overnights (23.4/34) of the network's very popular "Lonesome Dove" miniseries when it debuted on a Sunday night last February. That rating rose higher in the final national ratings. Each overnight ratings point currently represents some 470,000 TV homes ...

"Sarah, Plain and Tall" did even more handsomely in the nation's capital, averaging a Redskins-like 30.9/42 on Channel 9, compared with an 11.8/16 for "In Broad Daylight" on Channel 4, a 9.9/14 for "Son of the Morning Star" on Channel 7 and a 9.7./14 for the combination of "Cops" and the 10 o'clock news on Channel 5. A local ratings point represents 17,491 TV homes ...

Channel 26 -- which saw the "In Performance at the White House" series move to a public station in Rochester, N.Y., last fall -- has lost corporate underwriting for another of its "signature" series, the six-year-old "Smithsonian World" ...

Southwestern Bell, headquartered in St. Louis, has notified the station that it will not renew its contract after this June. Southwestern Bell has underwritten the series, which is a co-production of WETA and the Smithsonian Institution, for the past three years ...

WETA has provided the administrative and financial support for the series while the full range of the Smithsonian's fabulous resources has been available to producers over the years ...

For the current schedule of five programs, which began last month on PBS and concludes in June, the company provided $1.3 million. The public broadcasting stations also gave $500,000 ...

Late last year PBS programming czar Jennifer Lawson signaled the public TV system that "Smithsonian World" was facing a tough future when she notified stations PBS would not provide funding for the series past the current season. At the time, however, WETA management denied the series was in jeopardy ...

But yesterday, Richard Hutton, WETA senior vice president for television programming and production, said, "It will be very hard to get another sponsor at this late date" in time for the next season ...

But spokesmen for both the Smithsonian and WETA insisted yesterday that the search for a corporate underwriter will continue ...

Hutton said the withdrawal by Southwestern Bell would have no immediate impact on jobs at WETA. Sandra Bradley, executive producer of the series, said yesterday she was hopeful "Smithsonian World" will continue. She predicted that there would be little direct impact on the four independent producers currently involved in producing the series ...

Bradley's Silver Spring firm, Wentworth Films, is producing two of the programs. Three other independent producers -- York Associates in Washington, Werner Schumann in Cabin John and Peace River Productions in Boston -- are each contributing one ...

Bradley said all four firms produce programs on an ad hoc basis and that the Southwestern Bell decision will not directly affect permanent staffs. However, a "central staff" of four that oversees the Smithsonian series could be disbanded if no other sponsor is found, she said ...

"It's an artistic and editorial disappointment," Hutton admitted yesterday, "but its loss right now doesn't really represent a financial crush" ...

He pointed out that neither the loss of "In Performance at the White House" nor of "Smithsonian World" was based on "any dissatisfaction with the productions." The move to another venue of "In Performance," which will continue to be funded by Ameritech, was a Bush administration decision ...

In its first three years on the air "Smithsonian World" was underwritten by McDonnell Douglas, the St. Louis-based airframe manufacturer, which was forced to withdraw because of economic problems ...

Madeleine Jacobs, spokeswoman for the Smithsonian Institution, said yesterday it was her understanding that Southwestern Bell "wished to put its funding primarily but not exclusively into sports events" in the five-state area served by the conglomerate.

"They've redirected some of their priorities," said Jacobs. "It's been a happy relationship. It's very sad, they've been a wonderful sponsor" ...

Other sources indicate that a new chief executive officer at Southwestern Bell made the decision to emphasize sports promotion instead of cultural programming on TV. Attempts to reach a Southwestern Bell spokesman were unsuccessful yesterday ...

The Smithsonian series, which probes people and events that shape American culture, is the winner of 40 awards over the years, including three national Emmys -- one, a primetime Emmy -- and two Ohio State awards ...

"WETA is scrambling right now," one public TV executive said yesterday. "In the past six months, they've lost the two series that most identified it with Washington for the PBS audience" ...

Hutton, of course, quarrels with that assessment, but admits that in the current economic environment Channel 26, like all public TV stations, is facing underwriting problems ...

Still, he said, the 1990-1991 season has been very good so far for WETA. Hutton pointed to the recent three days of coverage on PBS of the congressional debates on the war, produced by WETA, as well as the special services offered by "The MacNeil/Lehrer NewsHour," a WETA-WNET co-production since the outbreak of the war on Jan. 17 ...

He also cited the impact on the national PBS schedule of other WETA programs, including "The Civil War," the Moyers special on Florence, the five-part series "The Soviets" and the current David Frost interview series ...

"You look at the PBS schedule this year," said Hutton, "and it's been a virtual overlay of WETA productions" ...

The next "Smithsonian World," a program devoted to advertising called "Selling the Dream," airs Feb. 13 ...

In Other News

The sitcom "Down Home" will return to the NBC Saturday night schedule, replacing "The Fanelli Boys" ...

"Down," which had a six-episode run on the network last spring, returns with a Thursday, Feb. 28, "special" following "Cheers" and joins the regular schedule on that Saturday, March 2, in the 8:30 timeslot. "The Fanelli Boys," having exhausted its run of original episodes by then, will go to the dreaded "hiatus," but the network suggests it "may return next season"!!! ...

"Down Home," lest we've forgotten, stars Tony Award winner Judith Ivey as a successful N.Y. career woman who gives it all up to return to her Texas fishing village hometown to save the family business. Good girl, Judith! ...

Channel 4 announced yesterday that reporter Peter Ford returns home from Saudi Arabia today. He's been in the Persian Gulf area since Jan. 10 ...

ABC Television Network Group has named Philip R. Beuth president of ABC Early Morning and Late Night Entertainment programming ...

Beuth, who continues as the executive in charge of "Good Morning America," was named senior vice president for the two programming areas in December ...

Today at noon, "Nine Months," the weekly Channel 26 program that focuses on the lives of eight local pregnant women, will air a special call-in program ...

Five of the eight women will discuss their concerns and worries as their delivery dates near ...

The call-in number is 703-845-9797. That's 703-845-9797 ...

Television producer Harry Ackerman, who developed "Gunsmoke," organized the development of "I Love Lucy" and co-created "Our Miss Brooks" for CBS, died Sunday of pulmonary failure at St. Joseph Medical Center in Burbank, Calif... .

According to his publicist, Frank Liberman, Ackerman, 78, turned down a promotion to president of CBS Entertainment to remain in production ...

He also had a hand in such TV classics as "Leave It to Beaver," "Bachelor Father," "Dennis the Menace," "The Donna Reed Show," "Hazel," "The Flying Nun" and "Bewitched" ...

Nancy Kulp, who played secretary Miss Hathaway on "The Beverly Hillbillies," died Saturday in Palm Desert ...

Kulp, 69, had been suffering from cancer of the jaw ...