Powers of Ten - View the Milky Way at 10 million light years from the Earth. Then move through space towards the Earth in successive orders of magnitude until you reach a tall oak tree just outside the buildings of the National High Magnetic Field Laboratory in Tallahassee, Florida. After that, begin to move from the actual size of a leaf into a microscopic world that reveals leaf cell walls, the cell nucleus, chromatin, DNA and finally, into the subatomic universe of electrons and protons.
The Columbia Gazetteer of North America - With 50,000 entries, the Gazetteer covers every incorporated place and county in the United States, along with several thousand unincorporated places, special-purpose sites, and physical features, as well as Canada, Mexico and the Caribbean.
