Fifty years ago, Pacifica Radio correspondent Saul Bernstein recorded a 62-minute speech delivered in London by Martin Luther King Jr., in which the civil rights leader spoke about apartheid and the then-recent sentencing of Nelson Mandela. The recording, believed to be the only full record of King’s speech, was thought to be lost to time. But a half-century later, Pacifica Archives Director Brian DeShazor uncovered Bernstein’s recording in a dusty box while working on a Saturday, researching another project, “American Women Making History & Culture, 1963-1982,” a two-year effort funded by the National Archives to preserve hundreds of recordings. Now listeners to Democracy Now!, which airs on Pacifica’s five stations around the country, will hear the speech on the show’s Martin Luther King Day edition, and donors to the financially struggling network can receive a copy as a premium. DeShazor said he found the tape due to a lucky break.