Between 1935 and 1938 the celebrated photographer Roman Vishniac explored the cities and villages of Eastern Europe, capturing life in the Jewish shtetlekh of Poland, Romania, Russia, and Hungary, communities that even then seemed threatenednot by destruction and extermination, which no one foresaw, but by change. Using a hidden camera and under difficult circumstances, Vishniac was able to take over sixteen thousand photographs; most were left with his father in a village in France for the duration of the war. With the publication of Children of a Vanished World, seventy of...