[applause] >> the book is for sale outside, and i'm going to take jon kukla outside to go sign them.inaudible conversations] >> booktv's in concord, new hampshire. up next we speak with author howard mansfield about his book, "turn and jump," that explained how the concept of time zones came about. >> time first meant where the sun was in the sky. noon was where the sun is

>> the book is for sale outside, and i'm going to take jon kukla outside to go sign them. [inaudible conversations] >> booktv's in concord, new hampshire. up next we speak with author howard mansfield about his book, "turn and jump," that explained how the concept of time zones came about. >> time first meant where the sun was in the sky. noon was where the sun is exactly overhead. time is very local. time is nature. time is the course of the sun across the sky, it's the course of the moon, it's the seasons. and what happens is that clocks come along. first clocks represent time. clocks represent nature. the clock face mimics, you know, the passages. and by the end of the 19th century, clocks are time and nature is forgotten. and this happens for a lot of different reasons, industrialization, the railroads plays a huge role in this. you're no longer just on a little hillside in your little village. you need more accurate time if you're taking the train, because now you're going from one local place to another local place, everybody's got its own place. you might get off, a