For America it was one of the most remarkable days in the country's history. For television it was an extraordinary double-feature -- a thriller and a pageant.

It was a day that demonstrated television's role as the great adhesive of modern American society, the tie that binds us together by giving us the common experience that now define our nationhood. In living color, as the networks used to boast, the country yesterday exchanged presidents and simultaneously shared in the cathartic conclusion of an agnoizing national humiliation. What a show!

That this sensory overload was even tlerable demonstrates how television has expanded our capacity for absorbing experience from the ubiquitous box.

The two features on this twin-bill had nothing in common -- the networks' long-prepared and flowery coverage of our quadrennial coronation and the tense bulletins from around the world on the fate of the hostages. The camera shots jumped from Cronkite and Chancellor and Reynolds in their coronation mode to correspondents in Europe and Algeria, at the State Department and in the White House who were struggling to keep up with the breaking news.

This was not the movies, where one feature has to follow the other. This was television, where two utterly different shows can be spliced together. With the help of Iranian officials who behaved as if they, too, were watching on the tube, these parallel adventures proceeded in tandem, following a timetable of eerie precision.

So when it came to what should have been the new president's most important moment, his inaugural address, television viewers were caught in the crucial moment of suspense in the hostage adventure. The anchormen had said they were supposed to be leaving Tehran just before noon Washington time. Untied Press International moved a bulletin, read on CBS, saying they had left (they hadn't, as it turned out), but the anchorman would not vouch for the UPI report.

The experts might say that the deal was really firm this time, but television viewers had too much experience to buy that line.So Ronald Reagan's speech broke into the hostage adventure like a maddening commercial at the denouement of an exciting movie.

This must have cost the new president something in terms of viewer concentration -- the contents of his speech seemed less important on television than the time it was taking.

Even the tension over the hostages could not undo the magic of that moment when one president displaces another, a moment that embodies the legitimacy of the entire American system. But no sooner was it over than Sam Donaldson, network televison's most colorful correspondent, was shouting at the brand new president about the hostages, and the other half of the twin-bill was back on the screen.

Donaldson's intrusion was one of a dozen reminders during the day that television enjoys a license to participate in the great moments of our national life, not just to observe them. On CBS, that network's State Department correspondent, Robert Pierpoint, announced on the air with evident pride that CBS had brought lunch for all the diplomats on the Iran working group and sent it up to them on the eight floor.

And throughout the day the networks took us into the living rooms of hostages' families, where televison reporters were treated like favorite cousins, and the loved ones of those 52 long-suffering Americans apparently felt completely comfortable with wires in their ears and microphones on their shirtfronts, sharing intimate feelings spontaneously with millions of their countrymen.

Television also displayed its ability to legitimize emotions for the American public, a crucial element in its role as national adhesive. Frank Reynolds on ABC and Walter Cronkite on CBS let their anger and exasperation show in a way that sanctioned those feelings for all who were watching.

"One wonders," said Cronkite before he was sure the hostages had been released, "how devious, how Machiavellian, how diabolic the Iranians could be today." It was "difficult to avoid the conclusion" that the Iranians set out deliberately to spoil America's "joyous [inaugural] celebration" said Reynolds, shaking his head in anger. Commentary like this must have helped viewers articulate their own emotions, which is part of any good catharsis.

Traditionally, Inauguration Day belongs to the new president alone, but yesterday Ronald Reagan had to share it -- not only with the hostages, but with Jimmy Carter as well, who established a new national standard for staying busily on the job until the very last constitutionally permitted moment, and even a little beyond.

Traditionally, too, a new president's first days in office give him an opportunity to set the tone and style of his administration with unparalleled access to the mass media, all of whose attention is focused on him. But this new president will have a different experience; he will be sharing top billing with a story that is intrinsically much more interesting to the public than his first official proclamations and decisions.

Television will run to the hostage story in the days ahead the way one of those dogs in the commercials runs after Alpo. A polished performer like Reagan will still have numerous opportunities to take the stage, but he also faces an early challenge to his political skills to avoid being buried in the hostage story.