T.S. Matthews is almost as old as the century and has been witness to much of its excitement and glamor. Born into high privilege as an heir to the Procter & Gamble Co. fortune, he chose journalism over business; beginning with The New Republic in the 1920s, he moved over to Time magazine (of which he eventually became managing editor) and then entered a career as free-lance writer and memoirist. "Angels Unawares" is his latest venture in this latter pursuit, a collection of brief portraits of men and women -- and one Jack Russell terrier -- whom Matthews held in higher than customary regard.

They are a mixed lot, and "Angels Unawares" is a mixed book. Its two best chapters are about rather eccentric men for whom Matthews had great if unsentimental affection: John Potter Cuyler, who for a time was Matthews' father-in-law, and Whittaker Chambers, with whom Matthews worked at Time. The less successful chapters, of which unfortunately there are quite a number, are brief portraits in which Matthews either fails to bring his subjects alive or fails to demonstrate a connection with his subjects sufficiently strong to justify writing about them.

Matthews was an adolescent when he first met Cuyler, who lived in Princeton, N.J., with his large family and intermittently conducted an undistinguished career as an artist. His real vocation was as an observer of the passing show and as a consumer of its greatest pleasures, among them good drink and good fellowship. He was given to aphorisms, whether his own ("The only perfect climate is bed") or those of rustic philosophers ("As soon as you get out of bed in the morning, it's ten to one against you"). His large family included his wife's uncle, Dr. Alfred Baker, a gentle old fellow of firm habits:

"He insisted on going to the post office to mail his letters, of which he wrote several every day, because he answered all his second-class mail. Again and again Mrs. Cuyler would point out to him that an advertisement from Realsilk Hosiery or Wearever Shirts was not meant to be answered. Dr. Baker was unconvinced. 'This young man has taken the trouble to write to me, Julie, and it is only courteous that I should reply to him.' "

Matthews has a fine hand for anecdotes such as this, and when they present themselves he tells them with the enthusiasm they deserve; these include the story of an old maid who asked Albert Einstein's wife if he might be interested in chess and was told, "Jezz? Not in zis house!" He is also skilled at painting balanced portraits of complicated characters, of whom none was more complicated than Whittaker Chambers. On the one hand there was the "air of suppressed melodrama about him," his contemptuous treatment of those he regarded as his intellectual inferiors, his "melodramatic descriptions of Communist methods, especially in the field of international conspiracy." On the other there was the domestic Chambers:

"After the tumult of the Hiss trial, Chambers lived in isolation with his wife and two children on his Maryland farm. I used to go there to see him. I often wished that the people who were so sure he was a scoundrel, or those who had doubts of him, could see him at home with his family or could meet his wife, Esther . . . Neither Chambers nor his family ever drank spirits, but whenever I came there was always a bottle of whiskey for me. Esther was a good cook, and those farm meals were feasts. In his own house, Chambers was not the sardonic, warily silent character he seemed outside, but hospitable, relaxed, almost talkative."

These portraits of Cuyler and Chambers, affectionate yet clear-eyed, are the high moments of "Angels Unawares." Though there are other good ones, most of the rest tend to fall into predictable categories: passing encounters with the eminent, of the famous-persons-I-have-met variety to which retired journalists are unfortunately addicted; sketches of family members whom Matthews fails to make interesting to readers not privileged to belong to the family; and portraits of various retainers -- chauffeurs, governesses, odd-job men, bootleggers -- that are intended to be affectionate but succeed primarily in being patronizing.

All of them are redeemed, though, by Matthews' sharp eye and smooth prose. Like John Potter Cuyler he has his view firmly fixed on the human comedy; more often than not he sees through its vanities with clarity, and he describes them with a cranky tolerance that is not without charm. "Angels Unawares" is not a very substantial memoir, but its best moments are good ones indeed.