In Travelling Sprinkler, Nicholson Baker revisits floundering poet Paul Chowder, the protagonist of 2009’s The Anthologist, and finds him abidingly disengaged. Pining for ex-girlfriend Roz, he seeks solace in protest songs, political hand-wringing, garden implements and other passing distractions, including a desire to be taken seriously as a cigar aficionado. Through it all, he has...