DescriptionEn-us-silicon.ogg English: pronunciation US speaker (NJ) Date 26 October 2011 Source Own work Author Jcwf...
domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929. Public domain works must be out...
domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929. This file has been identified...
Washington : Smithsonian Institution Press, [etc.]; for sale by the Supt. of Docs., U.S. Govt Print. Off. Description Many numbers issued in parts No. 56, pt. 2...
domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929. Public domain works must be out...
production of silicon carbide, a synthetic mineral. After the first few images are shown of a sand grindstone from the era before silicon carbide (depicting...