A historian is sometimes forced to read books published several decades, in some case even centuries back, in order to tease out information that is relevant. Antony Grafton, in his The Footnote: A Curious History has drawn attention to this rather interesting aspect of historical research. Unlike other strands of knowledge in which one can see a cumulative increase in human understanding, in historical research there is search for new quetions about the past and new ways of understanding and...