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Purple parchment. Purple parchment or purple vellum refers to parchment dyed purple; codex purpureus refers to manuscripts written entirely or mostly on such parchment. The lettering may be in gold or silver. Later [when?] the practice was revived for some especially grand illuminated manuscripts produced for the emperors in Carolingian art and ...
A lever tumbler lock is a type of lock that uses a set of levers to prevent the bolt from moving in the lock. [1] In the simplest form of these, lifting the tumbler above a certain height will allow the bolt to slide past. The number of levers may vary, but is usually an odd number for a lock that can be opened from each side of the door in ...
Duplicating machines were the predecessors of modern document-reproduction technology. They have now been replaced by digital duplicators, scanners, laser printers and photocopiers, but for many years they were the primary means of reproducing documents for limited-run distribution. The duplicator was pioneered by Thomas Edison and David ...
A mimeograph machine (often abbreviated to mimeo, sometimes called a stencil duplicator or stencil machine) was a low-cost duplicating machine that worked by forcing ink through a stencil onto paper. [1] The process was called mimeography, and a copy made by the process was a mimeograph . Mimeographs, along with spirit duplicators and ...
Analog of the Japanese Type B Cipher Machine (codenamed Purple) built by the U.S. Army Signal Intelligence Service Purple analog in use. In the history of cryptography, the "System 97 Typewriter for European Characters" (九七式欧文印字機 kyūnana-shiki ōbun injiki) or "Type B Cipher Machine", codenamed Purple by the United States, was an encryption machine used by the Japanese Foreign ...
A school newspaper published using a ditto machine in 1978. A hand-cranked spirit duplicator from the 1960s. The duplicator uses two-ply "spirit masters", also called "master sheets". The first sheet can be typed, drawn, or written upon. The second sheet is coated with a layer of wax that had been impregnated with one of a variety of colorants.
A Polygraph is a duplicating device that produces a copy of a piece of writing simultaneously with the creation of the original, using pens and ink. Patented by John Isaac Hawkins on May 17, 1803, it was most famously used by the third U.S. president, Thomas Jefferson, who acquired his first polygraph in 1804 and later suggested improvements to ...
Pin tumbler lock. A common type of pin tumbler lock, of the euro cylinder type. The pin tumbler lock, also known as the Yale lock after the inventor of the modern version, is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key . Pin tumblers are most commonly employed in cylinder locks ...