Longitude

in the spirit of the chicago festival of maps happening later this year, i recently picked up dava sobel's longitude, and i highly recommend it. it's a short book that won't take you more than a few hours to read, but it's a short and sweet tale of the so-called longitude problem that plagued explorers and seamen for many centuries. dobel writes very well and the book is packed with memorable stories, such as the story of the "powder of sympathy," proposed as a means to determine longitude by painfully healing at a distance. the process would be simple, as dobel writes:

"send aboard a wounded dog as a ship sets sail. leave ashore a trusted individual to dip the dog's bandage into the sympathy solution every day at noon. the dog would perforce yelp in reaction, and thereby provide the captain a time cue. the dog's cry would mean, 'the sun is upon the meridian in london.'"

wonderful stuff. read this book.