The Senate, in its dressing-room before facing the cameras, was all aflutter. Would television change its stately ways? Would it, heaven forfend, change its rules?

It was a gala day, no question about it. There were buttons and mugs proclaiming the wonder of the occasion, and nobody hesitated for a moment to call it "a historic day" -- although Sen. Charles McC. Mathias Jr. (R-Md.) gently reminded them that this was a matter for history to decide.

On the basis of the first hour of the first day when the four Fujinoon A44 x 9.5 cameras mounted in the gallery were trained on the chamber, it seems safe to say that the Senate will remain itself in the electronic age.

Its self-consciousness, its tedium, wordiness, predictability -- and truancy -- are all too deeply ingrained to be undone in a day. Monday is Monday, when most senators are still dawdling in their districts.

No changes in decor were made for the momentous inaugural. The set is the same, the small highly polished schoolboy desks, the gleaming brass spittoons, the figured carpet, the brocaded walls -- the rows on rows of empty seats.

Republican Majority Leader Robert J. Dole (R-Kan.) in the role of master of ceremonies rose up at 2 p.m., which is two hours later than the usual opening hour of noon. The delay was quintessentially senatorial. Democratic Minority Leader Robert C. Byrd (D-W.Va.) was scheduled to give the commencement address at a Logan High School in West Virginia. Actually, he didn't make it to the podium, because of fog, but senatorial courtesy had been obliged.

Three Republicans -- Mathias, Pete Wilson of California and Charles E. Grassley of Iowa -- were in their seats, when Dole, sporting an oversized button that had all the subtlety of a billboard on a highway under construction ("TV in the Senate, Robert Dole Majority Leader") began to explain how the cameras brought home to all senators their "responsibility to make things move."

He thanked Howard H. Baker Jr., the former senate majority leader and present presidential candidate who was on hand for the festivities, for pushing the Senate, "to catch up with the 20th century."

To hear Dole talk, you would think that words, by which the Senate has lived, had no meaning, or at least no power. All those reporters who have sat in the gallery for generations, scribbling down everything said, racing to put it into newspapers, magazines and books, were, it seems, kind of wasting their time. The historians who painstakingly recreated the demeanor, tone, and verbatim from the Congressional Record, failed, too. Only with videotape comes reality.

"No longer,"said Dole, "will great debate be lost forever."

He mentioned Daniel Webster, John Calhoun and Henry Clay, whose giant utterances might have survived had television cameras been on hand.

Byrd, who spoke for an age, and for the ages, continued on the theme of the Senate being "discovered" by television. "The American people think Congress consists of one house," a reference to the fact that the House of Representatives has been videotaped for seven years while the Senate languished in the shadows.

Byrd suggested that the Civil War might have been staved off had the debates been filmed. He speculated that the "Vietnam war might not have become the war it was if those floor debates were covered by television."

Things went on in this vein for a while, when Sen. William Proxmire (D-Wis.) got up and spoiled everything by bringing up an issue, one that went beyond process into substance, an area which the Senate most reluctantly approaches.

"We have two alternatives to reduce the nuclear threat," said Proxmire baldly, without the slightest reference to what television would do to the Senate or what the Senate would do to television. He made one concession: he held up a little colored chart and a dollar bill to show the comparative costs of "Star Wars" and an arms control agreement.

Sen. Edward M. Kennedy (D-Mass.) also dwelt on a subject which in the long run could matter more than the number of addicts made by C-Span coverage. He spoke of the president's breathtaking, casual ditching of the SALT II arms control treaty. Reagan last week, after announcing he would dismantle two Poseidon submarines, added that he was abandoning the treaty. Defense Secretary Caspar W. Weinberger gloated that the United States "is no longer bound" by SALT II and Secretary of State George P. Shultz proclaimed it "obsolete." The only Democrat who responded with the baseball bat rhetoric required was President Jimmy Carter's arms negotiator Paul Warnke, who said it showed that "the nuts have won" in the Reagan White House.

Kennedy said it was the "worst decision of the Reagan administration."

The Senate is always transfixed by its own image, and being televised deepens its self-absorption. If television convinces it that its duty is to debate the issues, and not itself, it could pick up a few daytime television fans.