For our #TBT today, here's a shot of one of the many rare books that the USGS Library has in our rare book room. This is 484 year old copy, written in Latin, of the Historia Mundi by Plinius Secundus. This, along with other rare books held by USGS, are a wealth of knowledge about our planet and history. Read more about the USGS Library: library.usgs.gov/