Of particular interest to me, this book details the pre-industrial sleep pattern of segmented sleep, in particular describing "first sleep" followed by a period of "watch" and subsequently "second sleep". A Library of Congress webcast featuring the author discussing his book (http://www.loc.gov/today/cyberlc/feature_wdesc.php?rec=3730) describes "At Day's Close" this way: "examines the history of nocturnal activity in society in Western Europe, from Scandinavia to the Mediterranean, before the advent of the Industrial Revolution. Ekirch describes how nighttime embodied a distinct culture, with many of its own customs and rituals. Ekirch, a professor of history at Virginia Tech, conducted much of his research on the book at the Library of Congress. Ekirch writes about night perils, official responses to nighttime such as curfews and watchmen, haunts of men and women at work and play, bedtime rituals, sleep disturbances and finally the demystification of darkness underway in cities and large towns by the mid-18th century."