Dr. Roy W. Wampler of the Libbey-Owens-Ford Glass Company polishing one of the cover plates of the glass and metal assembly of the enclosure housing the Declaration of Independence. Dr. Luther H. Evans, Librarian of Congress, watches. The glass plates of the enclosures were made of special tempered glass and soldered to a lead strip sealing the documents into an airtight envelope.
National Institute of Standards and Technology
National Institute of Standards and Technology