Replies to post #200268 on Tornado Alley (PROG)

[F6]

Time and Navigation: How We Found Our Way in the World

The newest exhibit at the Smithsonian's Air and Space Museum explores the long history of path-making.
Apr 14 2013
http://www.theatlantic.com/technology/archive/2013/04/time-and-navigation-how-we-found-our-way-in-the-world/274970/ [with comments]; http://timeandnavigation.si.edu/