In the first chapter of this disappointing book, science journalist Whitaker promises an exhilarating adventure: One Sunday afternoon in 18th-century Peru, wealthy, willful small-town society matron Isabel Godin set off to trek thousands of miles through the Amazon jungle to reunite with her French explorer husband after 20 years apart. Unfortunately, Whitaker then puts Isabel’s story on standby, launching into an exhaustive history of European cartography that spans centuries — and a hundred pages. Isabel’s intriguing story doesn’t really resume until halfway through the book (if restless, skip to page 151). Bottom line? Less mapmaking, more wife.