On the day Time magazine announced it was buying The Washington Star, The Daily News was confirming its virtually certain folding in Chicago. Two troubled afternoon papers, two cities half a continent apart, two celebrated properties.

The death of the The Daily News will leave the nation's second largest city -- a metropolitan area of 7 million people -- without an afternoon newspaper. The saving of The Star in the Nation's Capital -- an affluent metropolitan area of 3 million -- will ensure two daily papers in Washington.

These are not isolated events, nor are they without national significance. They highlight changes in reading habits, the continuing problems of many once-great American papers, particularly in the afternoon field, the increasing influence of conglomerates and chains over surviving daily journals the special impact of television, and the evolving role of the written press itself.

First, a little history, and some deadly arithmetic.

One of the major stories of the 20th century has been the rise of the mass media and its corresponding influence on popular tastes, attitudes, fashions and politics. (Anwar Sadat is only the latest to learn how to use the media to his own advantage.) For decades, it was the written side of the press that led the way. During the years of World War I alone, for instance, advertising revenues in American newspapers soared from $275 million to $650 million. By the end of the '20s, newspaper advertising revenues had shot up to $860 million.

The dollars followed the readers: newspaper circulation was rising in steady progression, up and up. By the beginning of World War II, some 40 million Americans were buying daily newspapers. The national population then was about 130 million.

Ten years later, the war and its postwar period of dramatic growth and change having passed into history, the newspaper business still more than held its own. In a population of 150 million, a record number of 54,017,938 people were buying daily papers.

Then the figures begin to change. By the early '60s there were 30 million more Americans but only an increase of 2 million in newspaper buyers. As the population moved well over 200 million, figures compiled in the mid-70s showed newspaper circulation actually dropping in total numbers, while the overall population continued to increase. Total circulation stood at 60 million --some 2 million less than at the start of the '70s. All this, too, coming at a time of further evidence of the decline -- and demise --of numerous mass-circulation journals. The death of Time Inc.'s famous flagship, Life, was the most notable example.

But these are only the general facts; the personal ones are more compelling, and confounding.

In these days of market research and attitude surveys, of corporate efficiency experts and computer technology, there are answers to everything, it seems -- that is, what passes for or pretends to be answers. There are even corporate "doctors" who diagnose ills and prescribe remedies, including those in the newspaper business.

Some people have made a living by urging adoption of certain formulas -- how to write, how to display, how to entice. When the formulas fail, and the patient dies, the postmortens invariably fall into a predictable pattern: the paper failed to keep pace with changing times; it had become insular, isolated or arrogant; it put a cash register in place of its editorial heart; it lacked courage or conviction.

But none of these satisfactorily explains why The Chicago Daily News is boundering. To anyone in the newspaper business, that name alone stands for much more than merely another big-city daily.

For more than a century. The Chicago Daily News has been an illustrious newspaper beacon, lusty, irreverent, forceful, with worldwide influence through a traditionally distinguished foreign service. In its long and colorful history it gave voice to such varied talents as Eugene Field, Leland Stowe, Robert J. Casey, Ed Lahey, Paul Scott Mowrer and Edgar Ansel Mowrer, Peter Lisagor and Mike Royko. More important, over the decades it has been welcomed into the homes of millions, and has achieved great financial success.

Its progress was a part of the history of Chicago. When it passed the 100,000 circulation mark scarcely 10 years after its birth, in typically brash fashion its owners fired off 100 guns on the lakefront. Like Chicago itself, it wanted the world to take note. In three more years, its circulation doubled. And when, years later in the mid-1920s. It passed into other hands, the price of $13.5 million was the highest ever paid for an American newspaper.

The Daily News continued to prosper for years afterward. By the mid-1950s, its circulation stood at 573,023. Then, in an all-too-familiar pattern, its readers began falling off dramatically. In 1965, its circulation was 469,688. By 1970 it slipped to 452,955. And in the three years from 1974 to 1977, circulation plummeted from 397,598 to 329,078.

Figures like those occurred at The Washington Star. In 1971, Star circulation stood at 418,126. Five years later it had fallen to 385,240. Its latest figures show a further loss of nearly 36,000 more readers.

In both cases, these declines came in the midst of intensive efforts to revitalize the papers. Money, energy, talent have been poured in, new sections, layouts, approaches instituted. And still the decline. Why?

The conventional answer is that television, the place where nearly three out of four people now get their news, has permanently altered the reading habits of Americans. In particular, TV has cut into the marrow of the afternoon newspaper field.

Obviously, TV has had great impact. But there's more to the answer than that. No one has ever successfully explained another well-documented phenomenon. As papers die, a large portion of their erstwhile readers simply stop buying other papers. The readers vanish. Surviving papers, increasingly monopolies, become powerful economically but reach of fewer of the total potential readers in their communities. And no one seems to know quite how to get them back, to say nothing of even reaching them. In other words, how do you even get their attention, and what is it these citizens would like to read, if indeed they know.

The questions are not academic. Implicit in them is a judgment by, and perhaps a commentary on, today's better educated more sophisticated American citizens. And now television is being forced to ponder the same difficult questions. For the first time, TV viewers, too, are beginning to decline.

This subject is not academic, either. When I grew up in New York there were eight daily newspapers, offering highly differing views and styles. Today there are three. It was my father's unhappy experience to have written the obituary for one of them, The New York Sun. In its great days, long ago under the editorship of Charles A. Dana, The Sun was the most famous of all American newspapers, the goal of newspaper people around the nation. "I wish I had been able to tell how newspaper people feel --that a good newspaper has a heart and a soul and that to them the death of a newspaper is as grievous and personal as a death in the family," my father wrote later. "But I didn't and I couldn't.

So while I mourn the death of The Daily News and the stilling of one more voice in the choir, I rejoice at the prospect of a strengthened Star, control by a billion-dollar conglomerate notwithstanding.