CAMBRIDGE, ENGLAND, DEC. 5 -- Ronald Reagan's political legacy may be tarnished a bit back home, but he's still a shining star on the road, as he demonstrated again today in an appearance at the hallowed Cambridge Union Society here.

The union -- a debating society at which, in the brandy-soaked days before egalitarianism and women members arrived, young Englishmen smoked cigars, compared family trees and laid the groundwork for careers in politics -- invited Reagan to address its 175th anniversary.

He obliged with a star turn, a brisk but sweeping account of his years in the White House that captivated an ardent young audience of about 300 students. They laughed at the old jokes, sighed appreciatively at the tender moments and rewarded the veteran performer with a standing ovation at both the beginning and the end of his 40-minute address.

The speech itself was mostly a nostalgic collection of Reagan's greatest hits, delivered with the low-key affability that is the former president's trademark. There were long, solemn passages on the triumph of democracy and the death of communism, but not a word about the Iran-contra affair or the savings and loan crisis or the trillion-dollar federal debt his administration left behind.

Reagan took a few good-natured swipes at some old-time enemies, including "the foreign affairs establishment" and "the arms-control fraternity" who he said had questioned his stance of "peace through strength" and had denigrated his Strategic Defense Initiative ("some tried to trivialize it by calling it Star Wars"). He consigned the phrase "evil empire" to history's dustbin, but spoke instead of the Soviet Union's past "evil leaders" and noted that they had lost the battle of ideas to the West.

There was much praise for Britain's recently retired prime minister, Margaret Thatcher, his ideological soul mate. Reagan called her "a staunch ally and a good friend ... a remarkable lady whose achievements will be appreciated more and more as time goes on." He did not make reference to her sudden, rude political demise two weeks ago at the hands of rebellious members of her own party.

It was a canned speech, one Reagan seemed to have given many times before. But with no microphone, no TelePrompTer and little distance between himself and the admiring audience, Reagan seemed older, smaller, more fragile and somehow more real than he ever did on television. He sounded real as well, frequently stumbling over words and phrases as he made his way down a text from which he never appeared to deviate.

He paid tribute to what he called the "British heritage of free and open debate of ideas" -- but took no questions himself.

That did not matter to the crowd, which seemed to hang on every word. Afterward, Reagan attended a lunch in his honor at St. John's College here that was sponsored by the International Herald Tribune.

Having just watched the forced retirement of a world-renowned leader of their own, the British are in the mood to be generous. As a soothing contrast to Thatcher's harsh, confrontational style, Reagan's aw-shucks folksiness and warm smile have always gone down well here. Herald Tribune Publisher Lee Huebner said the woman who served tea on the bus ride up from London said of the former president, "You know, I feel as though I know him. What a wonderful man."

Reagan arrived in London on Monday for a semipublic visit with his wife, Nancy, who did not accompany him on the day trip to Cambridge. It was his first visit to this country since Queen Elizabeth knighted him in June 1989.

He returned to London this afternoon to take tea with Prince Charles and Princess Diana at Kensington Palace. On Thursday he is to have lunch with the queen and Prince Philip at Buckingham Palace, then tea at Claridge's Hotel with Thatcher and her husband, Denis.

The former president came under fire last year for taking a $2 million paycheck for addressing business audiences in Japan. Today's lecture, by contrast, was free and billed as a personal tribute by Reagan to a great university and to a country whose ideals and traditions he deeply admires.

After the speech he was made an honorary member of the union and given a tie and university sweat shirt. He picked up another tie at the Herald Tribune lunch. He said both were likely to end up on display at his new presidential library outside Los Angeles -- where presumably they will join a vast collection.