President John F. Kennedy's secretly recorded tapes apparently have been used on only one occasion, by Robert F. Kennedy in the preparation of his book on the 1962 Cuban missile crisis, according to the director of the Kennedy Library.

"Thirteen Days," published in 1968, contains detailed, verbatim quotations from the sensitive missile crisis meetings. Library officials indicated these quotations may be the only chance the public will have in the next few months to look at material from the 600 conversations recorded during John Kennedy's last 16 months in office.

The men who were recorded by President Kennedy, including his closest advisers and confidants, said yesterday they had not known at the time that Kennedy was taping conversations with them. Many of them generally defended the practice, with some chagrin and reluctance, as being helpful for the preparation of presidential history.

Sen. Edward M. Kennedy (D-Mass.) refused to answer questions about the tapes or the propriety of his brother's practice of taping people without their knowledge. He issued a statement expressing confidence that "Americans will continue to be proud" of his brother's presidency "after the transcripts . . . are prepared and released."

The senator said in his statement that the transcripts of the recordings would be made public "as soon as possible" but gave no indication when that would be.

Kennedy noted in his statement that the existence of recordings made by President Kennedy had been announced in 1973 by the Kennedy Library staff. But the extent of Kennedy's practice of secret tapings was not known until yesterday, when The Washington Post published information from the logs of those tapes detailing the names of the participants and the subjects discussed. For a text of the logs, see Pages A21 and A22.

Previously, news reports have disclosed that presidents beginning with Franklin D. Roosevelt and ending with Richard M. Nixon had used some form of taping system on at least some occasions. Roosevelt taped seven or eight conversations plus 14 news conferences. And Harry Truman's library, according to its director, contains about 10 tapes that are "really unintelligible . . . you can hear somebody walking across the floor, hear a word here or there. But you can't tell what was said at all."

Spokesmen for presidents Gerald Ford, Jimmy Carter and Ronald Reagan all said that there was no taping of private conversations or meetings in their White Houses.

Vice President Bush said, "It's abhorrent to me to tape people during private conversations without their knowledge."

Yesterday, the men who advised President Kennedy spoke in terms of assuring the accuracy of history when asked about the taping, which was done without their knowledge.

Former defense secretary Robert S. McNamara said he felt "frankly rather relaxed" about the knowledge that a number of his conversations with Kennedy were recorded and may someday become public. "History was unfolding," he said. "I'm happy to live with what I said."

McNamara reluctantly said he had some reservations about the practice of secret tapings. "I suppose I would say, I guess, that I'd prefer that I had known in advance that I would be taped," he said.

Former secretary of state Dean Rusk voiced no such reservations. "When a secretary of state talks to a president about foreign policy he should always assume he is speaking for the record," Rusk said.

At times, Rusk said, there were microphones present on the coffee table in the Oval Office and on the conference table in the Cabinet Room. But at other times, officials now say, conversations were recorded by hidden microphones in those rooms and on the president's telephone. Still, Rusk said, he always assumed his conversations with the president would somehow be available for posterity. "Even when I was 'alone' with the president," he said, "there was usually a notetaker, such as McGeorge Bundy, present."

Bundy, who was Kennedy's assistant for national security affairs, was the only former Kennedy adviser who made no attempt to defend the secret taping by his boss. "I knew nothing of it at the time," Bundy said. ". . . I do not want to practice retrospective judgment of a president who's not here." He said he was sure the tape transcripts would not disclose a dark or profane side of Kennedy, as did the tapes of Richard M. Nixon. "The John F. Kennedy on the telephone will be the John F. Kennedy the country knew," he said.

Former undersecretary of state George Ball said that he was "unaware that he was doing that . . . but frankly I think it is a good idea in some of those meetings to make a clear record of what was said . . . . There basically isn't any privacy when you are a government official talking to a president." Ball added that he never taped conversations in his own office, but that he did have his secretary listen in on an extension and make notes, a common practice in Washington at the time. This was done, he said, even when it was the president on the other end of the phone and it was done without mentioning there was a third party listening.

As far as is known, Robert F. Kennedy is the only person to have used the tapes for publication.

"When Bobby did the 'Thirteen Days' book he sent for the tapes," recalls Dan Fenn, director of the Kennedy Library in Boston.

The book, published after Kennedy's death in June, 1968, was widely praised at the time, partly for its intimate account of the top secret war-and-peace deliberations in which Robert Kennedy was a leading participant along with his brother, the president, and the inner circle of Kennedy administration advisers.

Former British prime minister Harold Macmillan hailed the Robert Kennedy memoir by saying: "Each of these pages . . . is more thrilling than any fiction."

One of the book's strengths was its extensive use of verbatim, often long quotes from the various key players in the drama when the world stood in danger of nuclear warfare.

Because of the lengthy quotations, Fenn says, "he had to use them," referring to Robert Kennedy's possession of the tapes.

Fenn says he can't verify that each quote from the inner circle ExCom meetings over the missile crisis came from the tapes, but he presumes so.

An analysis of the book indicates Kennedy made extensive use of the tapes and logs of meetings and conversations. Its opening sentence, for instance, reads:

"On Tuesday morning, October 16, 1962, shortly after 9 o'clock, President Kennedy called and asked me to come to the White House."

Logs of the tapes now made available to The Post show President Kennedy taping discussions that day on Cuba. Later, in his narrative, Robert Kennedy writes of sitting in a critical meeting on Oct. 24:

"The voices droned on, but I didn't seem to hear anything until I heard the president say: 'Isn't there some way we can avoid having our first exchange with a Russian submarine--almost anything but that?' 'No, there's too much danger to our ships. There is no alternative,' said McNamara. "Our commanders have been instructed to avoid hostilities if at all possible, but this is what we must be prepared for, and this is what we must expect.'

"We had come to the time of final decision. 'We must expect that they will close down Berlin--make the final preparations for that,' the president said. I felt we were on the edge of a precipice with no way off . . . ."

The Kennedy book is filled with similar dramatic exchanges of verbatim conversation.

Fenn says that to his knowledge the Robert Kennedy book is the only use of the presidential tapes.

Ethel Kennedy, Robert Kennedy's widow, reportedly has said she didn't know of the existence of the tapes. But she wouldn't be surprised if her husband had used them in his book. He had a bad memory, she is said to have remarked in jest.

Edward Kennedy said through an aide that he was unaware of the taping system during the period of the Kennedy presidency, and that he had no knowledge that his brother, Robert, had made use of the tapes for his book.

The senator learned of the taping system only after his brother John's 1963 death, the aide said, adding that he has not listened to the tapes or read the transcripts. The aide said that the senator has no such system in his own office.

Republicans, including some who had been in the line of fire during the Watergate period, said they found the practice distasteful but were restrained in their criticism.

Former President Nixon's New York office said he would have no comment.

John Ehrlichman, a senior aide to Nixon who was jailed for his part in Watergate, said, "I doubt seriously it would have made any difference" if the extent of Kennedy's taping had been known at the time. "The Watergate thing had such a full head of steam up, I don't think you would have headed it off with this kind of information," he said.

As for the practice of taping, Ehrlichman said, "It's presidential nature, if not human nature, to want to be able to pin down who said what and who gets credit for what . . . . There's a pervading sense of one's place in history that seems to seize all presidents and even some national security advisers."

Dean Burch, a counselor to Nixon during the Watergate period, said he was unaware of the Kennedy tapes and believed "it might have made a difference, at least to the extent of legitimizing the taping of significant conversations. But I'm not sure it would have affected the outcome."

Burch said, "The Nixon tapes assumed a kind of sinister overtone because of the means by which they were discovered and the setting . . . but this might have caused the liberals a little more heartburn . . . ."

Clark MacGregor, the head of the Committee for the Re-election of the President during the time the Watergate scandal was breaking, recalled "Richard Nixon saying without rebuttal that it the taping system was not new to him, that it had been used by all previous recent administrations. I accepted that as a fact."

But MacGregor and Sen. Robert J. Dole (R-Kan.), chairman of the Republican National Committee at the time of Watergate, said they could not recall the disclosure of the Kennedy tapes in 1973 and were surprised by yesterday's stories. "I sure can't recall anything being said about it in '73," Dole said, "and I would have thought the Nixon people would have been searching for anything."

Both men said they doubted that knowledge of the Kennedy tapes would have spared Nixon from his forced resignation in 1974. "I think the content of the tapes disclosed in the Nixon White House was more shocking than the fact of the taping itself," MacGregor said. "If today's story had broken in '73 or '74, I don't think it would have made much of a difference." Dole said: "I don't think it would have stopped the process that led to the resignation, but he might have held on longer."

Both Dole and MacGregor said they found undisclosed taping distasteful, "a bad practice" in Dole's words. "If you want to record a conversation," Dole said, "say so. But hitting a button out of sight, I don't like it."

Without exception, the political figures who were revealed to have been parties to the taped conversations expressed surprise at the fact. Few of them seemed terribly angry.

Ex-representative Wilbur D. Mills of Arkansas, with whom Kennedy discussed tax legislation, said, "I'd phrase my sentences more carefully if I knew history was listening." He said he was less worried about language he might have used with Kennedy than if it had been President Johnson, with whom he had "some real cuss fights."

But Sen. Russell B. Long (D-La.) took a more caustic view of Kennedy recording conversations about legislation, Louisiana politics and integration in state jobs. "I consider it highly improper for anyone to record the conversation of a friend without informing the friend that a recording is being made," Long said. Even worse, he said, are partial recordings because they lend themselves to "misunderstandings."

Sen. Henry M. Jackson (D-Wash.), another of the conversational partners, said, "It's a question of right and wrong, and recording a conversation unbeknownst to the other person is wrong."

Former senator J.W. Fulbright of Arkansas said he disliked the practice, because suspicion of taping "further isolates a president from frank discussion and advice from his friends and critics . . . . It makes them self-conscious."

Others said they were not bothered. Former Mississippi govorner Ross Barnett (D), whose discussions with the Kennedy during the violence-ridden admission of the first black student at the University of Mississippi were recorded, said, "I don't care what they have on tape." Barnett said he had told Kennedy repeatedly that "I was going to enforce the segregation laws of my own state, and I don't care if that is recorded . . . . President Kennedy was a gentleman and he always treated me very well."

Pollster Lou Harris said he thought, on the basis of his own memory, that one call from Kennedy was upbraiding him "for some negative stuff" in a poll published in April, 1963 and, if there is a second call that day, "it was him calling me back, all charm, after he had blown off his Irish temper . . . . I don't resent it the recording at all. I trusted Kennedy and I still would . . . ."

Former California governor Edmund G. (Pat) Brown (D), said he was surprised but pleased that Kennedy's congratulatory phone call on Brown's victory over Nixon in the 1962 California gubernatorial race was in the archives. "I think he said, 'I wounded him, but you killed him,' " Brown said.

Former representative Wayne Hays of Ohio said, "I don't like anybody taping me unless I know of it . . . but if the conversation is when they were working on me to vote for their tax bill, it will be kind of amusing." Hays said he remembered talking with Kennedy and Secretary of Treasury Douglas Dillon, a Republican, "and I reminded Dillon he had contributed quite heavily to Nixon and then I made a couple other observations that others will find amusing."

"When do you think the tapes will be out?" Hays asked.

JFK Library director Fenn said yesterday that transcripts will not be released until summer. He estimated that two-thirds of the material will never be made public for reasons of national security.

Burke Marshall, an assistant attorney general under Kennedy and head of the three-member committee that controls release of the material from the library, said yesterday he has listened to one or two minutes of tape and that the quality was "very bad . . . There is lots of static, background noise . . . ."

Of the Kennedy advisers interviewed yesterday, there was only one who said he suspected the president might have been recording conversations. Kennedy's deputy special counsel, Myer Feldman, said he never knew that there was a taping system but that he thought at one point that there might be.

Feldman said that on one occasion, he and the president were talking about how the history of the Kennedy presidency would be written. "He said, 'We've got a pretty good story of it, or record of it,' " Feldman recalled. And since he was sure Kennedy did not keep a diary, he assumed that meant there were some tapes.

Feldman was asked if he thinks Kennedy should have told individuals that their comments were being recorded. "I can never say anything bad about Kennedy--he's my idol . . . . I'm struggling to say 'no,' but the answer is yes. Yes, he should have told us."

Logs of office meetings recorded on audio tape [TABLE OMITTED]

Logs of phone conversations recorded by Dictabelt [TABLE OMITTED]

Dictabelt logs [TABLE OMITTED]