BOOK REVIEW : A Fortuitously Timed 20th-Century Odyssey : THE JOURNEY FROM PRAGUE STREET <i> by Hana Demetz</i> , ST. MARTIN’S PRESS $16.95, 148 pages

Responding to the enthusiasm that greeted her first book, an autobiographical novel based on the author’s wartime girlhood in Czechoslovakia, Hana Demetz has followed “The House on Prague Street” with this appealing sequel.

In the spare, apparently artless language of a private diary, the author describes the years after her meeting with the dashingly intellectual man she would eventually marry. But “The Journey From Prague Street” is considerably more than the story of a romance; a long marriage; a late, abrupt divorce, and a fortuitous second love match: It is a candid, reflective account of a hegira that began in the bleak but still vibrant Prague of the late 1940s, an atmosphere both optimistic and ominous.

Aware that the city might be doomed to a desolate future, Helene and her lover, Paul, decide to flee to Bavaria while escape is still possible, hoping to emigrate from there to the United States. After an abortive attempt, they manage to escape to Munich, where the marriage flourishes in the relatively congenial ambience of the cosmopolitan German city.

There, Helene has her first intimations of Paul’s lifelong infidelity, accepting his philandering with a passivity surprising in so spirited a woman, setting a pattern that intensifies with time. When Paul and Helene get American visas, their story becomes a classic tale of immigrant energy and success.

At first, Paul works as an elevator operator while Helene supplements their income with her wages as a cleaning woman and salesclerk. After graduating from Columbia, Paul receives an appointment to Harvard and is soon recognized as a gifted lecturer and exceptional scholar--a career that offers him widely expanded opportunities for extramarital adventure. Helene graciously learns the role of stoic faculty wife.

In time, she asserts herself by becoming a teacher and writer. But it’s not until she’s 48 and Paul announces he’s finally leaving her for another woman that she fully discovers her own abilities and strengths. These chapters are written in the third person and present tense, serving as counterpoints for the events leading to the break. Here Demetz shifts into the first person and the past in a sometimes awkward attempt to show how the girl she was became the woman she is.

Honed by her wartime experiences, annealed by her rocky life with Paul and finally confident of her own talents, she becomes precisely the right person to embark on a marriage with a witty, loving, but virtually blind second husband.

Brief as it is, “The Journey From Prague Street” includes scenes from this marriage as well, vignettes that illustrate one woman’s progression from a harsh European past to a tranquil and satisfying American present. Helene’s story can almost function as the emotional autobiography of an entire generation. She’s every woman brought up to be a patient and self-effacing wife, only to find herself dislodged by rapidly changing manners and mores, rejected by a man determined to take advantage of them. Helene’s biography encapsulates a general experience, with one significant exception: Almost subliminally, she’s absorbed the implications of the moral revolution as she did the political upheaval of her youth.

“The Journey From Prague Street” lingers in the mind, a 20th-Century odyssey perfectly timed to find a sympathetic audience fascinated by the contemporary history of a suddenly conspicuous Eastern European country.

Next: Carolyn See reviews “Creative Differences” by Buffy Shutt .