President Carter looks up from his paperwork -- he is clearly puzzled -- as Zbigniew Brzezinski enters the Oval Office at 8:15 for the regular morning intelligence briefing.

There is another man behind Brzezinski, looking over his shoulder.

"Er, he's a photographer," says Brzezinski. "Well, it's an historic day -- and they thought it might be a good idea to have a picute taken."

Carter only half-smiles and looks quizzically at his national security adviser.

"Well, it wasn't my idea," Brzezinski says finally. "Really it wasn't."

Except for the photographer moving about the office plying his trade as the president and his adviser ponder a day's worth of classified cables, there is not much memorable about the way the day of the epoch begins for Jimmy Carter.

At 9:15 a.m., when Stuart Eizenstat comes in and discusses a matter of major domestic policy, the president is casually signing one of the side letters that accompanies the peace treaty as he listens.

Those who are in and out of the Oval Office find it hard to see anything that would indicate that their boss finds the day as momentous as they do.

And they do.

Patrick Caddell, the president's pollster, says, "Today is the kind of thing we can come back to -- always. Great presidents are measured by great events. And this will have an impact."

But just how much impact the day of Egyptian-Israeli peace will have for Carter is hard to say, even for the man whose job it is to translate Carter's popularity into statistics.

"It's not the kind of thing you can translate into hard specifics," says Caddell. And so he ists down and writes his boss a letter, in which he quotes Edmund Burke's eulogy to House of Commons member Charles Majes Fox in 1783:

"He may live long. He may do much. But here is the summit. He can never exceed what he does this day."

That is what a politcian gets when his pollster when to Harvard. Another adviser, a product of more southerly schooling, comes to the same view but phrases it differently:

"When Carter deals with the nittygritty, like energy and deregulation and all that, it doesn't do much to distinguish him from the pack -- from, say, a bunch of senators. But this will have a long-lasting benefit for Jimmy Carter. It will make him look presidential."

Presidential.

That is what the signing on the north lawn and the dinner on the south lawn under the orange-and-yellow tent mean for Jimmy Carter when seen through the eyes of his advisers.

The president looks presidential now, they feel, and they are probably correct.

There was a time just a few weeks ago when Carter was being advised by all sorts of experts outside (and a few within) that he needed to do something presidential and that he had better do it soon. That was after Iran had fallen and we were in danger of losing our Yemen. ("Ours" is North Yemen, which the map shows is really west; "theirs" is South Yemen, which is geographically east.)

Carter responded by sending an aircraft carrier to the scene, to float but not to fight, and promising arms to U.S. allies in the region. But at a time when others might have called out the Mayaguez one more time, Jimmy Carter summoned Air Force One instead. And he made his most presidential stand in a most unpresidential way.

He set out on a bit of shuttle diplomacy, the sort of thing usually left to pinstripe technicians. And all of the smart money said that he must have had the deal set from the beginning or he would never have done that. But the Carter men all say the smart money was wrong. And when success came at the end, the president's advisers were as surprised as the reporters covering them.

The fact that Carter returned with peace at hand meant just one percentage point to him in the polls, according to an NBS/Associated Press survey that compared his performance rating just before and just after his summit shuttle success.

But in fact, even then, it meant more. Because it also meant a reassessment, of sorts, in European capitals such as Paris and Bonn, where the government leaders were known to have a dim view of the American president and his competence.

"The man showed courage and sincerity," said French Foreign Minister Jean Francois-Poncet. "He took a step that probably would not have been made in conventional diplomacy because he involved not only the personal authority of the president but the authority of his entire country in an enterprise that was assuredly a risky one. So he deserves an 'A.'"

The French foreign minister then added with caution: "But the policy is the important thing and a policy... is judged on results.... I thing it is too soon to judge the results."

Another Western European diplomat offered this grudging admiration:

"It has become clearer and clearer that Mr. Carter is not stupid -- that he is not a primitive in foreign policy. Doubts remain about the American administration's goals and policies. There is the fact that it is not predict-able. But what this man has shown us is that when it comes to diplomatic negotiations, he is good. Very good. And now we must give him that."

So they give him that. And the question that the president's political advisers are now pondering is just how much the American people will be giving Carter for his role in making the peace between Egypt and Israel.

Carter has always scored well in the polls when the public is asked if he is a man they trust. Questions about his competence have produced fluctuating results. And the public opinion of him as a leader, at best not very high, has fallen to rather low -- 40 percent in a CBS/New York Times poll in January.

These figures are interesting but not important. What counts most is that the economic statistics continue to be bad. And the Carter advisers know that when that is the case, the public opinion atatistics are never going to be really good.

But the Carter officials hope that perhaps the signing of the Egyptian-Israeli peace treaty -- and the praise from Menachem Begin and Anwar Sadat -- will win him new marks for leadership.

"I think there is a real chance that this will be more than just the blip that occurred after Camp David," said one presidential aide. "... People will long remember the signing ceremony and the White House in the background. And to them that will always be Jimmy Carter."

EPILOGUE: At lunch at the White House, the Carters, the Begins and the Sadats start off with small talk and wind up discussing the last time a treaty was signed between the people of Israel and the people of Egypt. It was in the time of King Solomon.

Beging recalls that it was Solomon who signed for the Israelis. Sadat launches into a discussion about the signer for the Egyptians. And Carter observes softly:

"But no one remembers the mediator."