] circa 1200
]
] A Christian monk handwrites prayers in Greek over the
] Archimedes text, turning the old mathematical text into a
] new prayer book. The book is now a palimpsest, a
] manuscript with a layer of text written over an earlier
] scraped- or washed-off text (see What is a Palimpsest?).

This is an interesting link that was sent to my Kryptos brainstorming group. We've long been curious why "Palimpsest" was one of the keywords for solving one of the Kryptos sections, and whether it might give a clue for solving part 4. This information about Archimedes is intriguing. See the link, which includes some animations showing how one text was erased, the page was then turned 90 degrees, and another text written on top. The "90 degree twist" idea would completely change the part 4 ciphertext if we were to read things vertically. Hmmm...

The Archimedes Palimpsest