The report was coldly scientific, its source unassailably objective, its grave import unmistakably clear: at least as late as last October, an effort to conceal evidence in the Watergate scandal was still in operation in the innermost reaches of Richard Nixon's White House.
No such direct conclusion was explicitly drawn, of course, by the six professional sound, recording, and electronics experts who had exhaustively examined a presidential tape recording containing a mysterious 18-minute deletion of a Watergate conversation between Nixon and his intimate aide, H.R. Haldeman. It would have exceeded both their purview and their competence. But in reporting to...