Preston Library is a selective depository for U. S. government publications. The depository receives approximately 25% of all available items. You will find documents from Army Corps of Engineers, EPA, the Interior Department's Geologic Survey, and others. Access may be paper, microfiche and electronic. Topographical maps of Virginia are located in the map cases located on the 6th floor of Preston Library. See Col. Janet Holly, Research and Instruction Librarian, if you have problems finding a particular map.
A patent for an invention is the grant of a property right to the inventor, issued by the United States Patent and Trademark Office. Generally, the term of a new patent is 20 years from the date on which the application for the patent was filed in the United States or, in special cases, from the date an earlier related application was filed, subject to the payment of maintenance fees. U.S. patent grants are effective only within the United States, U.S. territories, and U.S. possessions. Under certain circumstances, patent term extensions or adjustments may be available.