How did salt and pepper become our default, go-to spices? Why are there four tines on a fork? How did stairs become so ubiquitous? These are just a few of the curiosities explored in Bill Bryson's latest book, 'At Home: A Short History of Private Life.' He discusses his latest literary endeavor with CityBeat in anticipation of his visit here Saturday for the Mercantile Library's annual Niehoff Lecture.