http://www.rssboard.org/rss-specification 720 XTF Search Results (docsPerPage=100;f2-subject=Patent extensions -- United States) http://catalog.wrhs.org/collections/search?docsPerPage%3D100;f2-subject%3DPatent%20extensions%20--%20United%20States Results for your query: docsPerPage=100;f2-subject=Patent extensions -- United States Thu, 01 Jan 1970 12:00:00 GMT Additional improvement patents, 1837-1861. United States National Archives and Records Service., Paulauskas, James A., 1929- http://catalog.wrhs.org/collections/view?docId=marc/skclmarc202890322046876.mrc http://catalog.wrhs.org/collections/view?docId=marc/skclmarc202890322046876.mrc Thu, 01 Jan 1970 12:00:00 GMT The petition of Daniel Pettibone to the Senate and House of Representatives of the United States, for the renewal of his patent for welding cast steel to iron, in such a manner as to be applied to edge tools or other purposes where steel is required. Pettibone, Daniel. http://catalog.wrhs.org/collections/view?docId=marc/skclmarc202890322046876.mrc http://catalog.wrhs.org/collections/view?docId=marc/skclmarc202890322046876.mrc Thu, 01 Jan 1970 12:00:00 GMT