In their new book Toilet: Public Restrooms and the Politics of Sharing (reviewed in this month's Cover to Cover), New York University sociologists Harvey Molotch and Laura Norén offer a series of essays about the the history, design, and use of public restrooms by an array of academic and cultural commentators.

In the slideshow below—featuring everything from multi-seat communal Roman toilets to modern-day British urinals that rise up out of the sidewalk—Molotch and Norén showcase a selection of images from the book, with accompanying commentary.