TIt is said that Washington is a one-industry town, and that Uncle Sam is its chief industrialist. But private business in Washington is also a force to be reckoned with. Sometimes, however, a combination of factors can put a business out of existence. The following, the fourth in a series of seven articles on D.C. business, is the story of one that did not last.

At the end of this month, Lane Shops will fold its branch at 1411 K St. NW. Gone will 1,300 square feet of medium-priced women's clothes and about $150,000 in annual sales. In their place will probably come a pizza parlor.

The tombstone, if it's accurate, will note that the store belonged to Lane for three months. The heart, soul and history of the place belongs to James B. and Sarah Epstein.

They operated a similar clothing shop at 1411 K for 14 years, under the name of La Belle Inc. Before that, says the man who bought thad out, Herbert Bargteil, they had run La Belle across the street "for about 110 years."

That is an exaggeration, of course, for 110 years ago, 14th and K was a remote corner of Washington, known chiefly as the place the horsedrawn Number Two bus ended its run and turned back toward Capitol Hill. Women's clothes were brought from seamstresses in those days, or made at home.

Forty-years was more like it. In that period, James Epstein built a reputation as a "fierce competitor," said Bargteil, the general manager of Lane's. EPstein's also made a good deal of money, apparently, although how much is not known.

But when he sold the fixtures and some of the stock to Lane in September, he "gave us a real good price, almost too good a price," said Bargteil. The Epsteins, both in their 70s, retired to Florida, without leaving so much as a forwarding address.

Gracle Branch, store manager for the Epsteins for seven years and manager for Lane for three months, thinks the Epsteins got out just in time. "People don't spend like they used to," she said one afternoon this month. "It's been dropping off all the time, for years."

That very day, she said, had been typical. Total sales: $170. Largest single sald: a $52 suit. Next largest: a $16 dress. Most of the total of 11 sales were an emergency pair of hose here, a cheap pair of gloves there. A lot of people had popped into the store, Branch said, "but just to look."

Bargteil said the K Street branch's chief problem was competition in the immediate neighborhood, most of it from two other Lane branches. They are located at 1028 14th St. N.W., about a block away, and at 1012 Vermont Ave. NW., in the next block. The company plans to keep them open, Bargteil said.

"We saw no reason to compete with ourselves," Bargteil said. "We don't need three of them in one city square block."

Lane located on K Street briefly so that it could showcase itself no one of the busiest downtown streets, Bargteil said. The company made back the $500-a-month rent, "plus a couple of dollars," he said.

He is leaving with no regrets, Bargteil added, although he said he is "sure nobody else could go in there with a women's clothing store." Indeed, a competitor, Turn Style, located 50 feet away at 1004 14th St. NW., folded at the end of December after only one year.

The Epsteins could not be located. But a friend and former neighbor said they decided to sell because they were becoming increasingly depressed by the deterioration of 14th and K.

"The Ambassador and the Hamilton used to be the best hotels in town," the neighbor said. "Over the years, (the Epsteins) just watched it all go down. Now you've got a McDonald's right there, and the prostitutes don't even wait for night any more."

Don Richardson, an executive for Greenhoot, Inc., which leases and manages the property, said its "location is good in terms of the amount of traffic that passes by." He theorized, however, that "the traffic just isn't the right kind for the women's clothing business."

Bargteil conceded that Lane had not done as well in its brief time on K Street "as we thought we would." But he defended the 14th and K area as "viable," and pointed out that the Epsteins, despite their discouragement, had done well there over the years.

"The man put down $49,000 cash on a condominium in Florida. I must have heard the story ten times," Bargteil said. "You know that's not all be made out of the place. He wasn't going to go down there eating beans and fritters."

Epstein did not changd his stock much over the years, Gracie Branch said. Nor is Lane's stock much difference. It consists mostly of simple slacks, dresses and pants suits, with some accessories. Few items cost more than $30. Bargteil said the clientele has been "80 per cent middle-class, middle-aged blacks.

"As we got larger and larger (at its two nearby branches), we encroached more and more on his lines," said Bargteil of Epstein. "He fought us tooth and nail for five years. That was why I was flabbergasted when he offered us the place."

Now, however, the place is little more than a sea of "Going Out of Business" streamers. Lane plans to absorb the four employees and all the unsold stock at its eight other stores, three of them in the District. Lane does not plan to return to K Street, Bargteil said.

The Epsteins evidently don't, either. "When they left," their former neighbor said, "the only reason they looked back was to see if a mugger was following them. They really cared about that palce, though. No pizza parior is going to be the same kind of place."