Toby Lester is a contributing editor to “The Atlantic” and has written an epic account of exploration and discovery in The Fourth Part of the World. In 1507, a German named Waldsmuller created a map which included the New World totally surrounded by ocean and named America. Prior to this, maps represented our the known world as a zonal map divided into three sections: Europe, Asia and Africa so this new map was momentous. Lester not only traces the history of this singular map but also examines the history of cartography and how maps of a time period represented more than just geographic knowledge, but also the beliefs and mores of those living. My favorite history book of the year. ~Patti