The Archimedes Palimpsest has re-appeared. This 10th-century manuscript bears seven works by Archimedes, in particular the only known rendition of "Method", in which Archimedes outlines his procedure for using physics to derive mathematical results. In the 12th century, parsimonious Greek monks recycled the paper and wrote the text of a prayer book over the original.
Only in 1906 was the significance of the document realized. The manuscript disappeared in the aftermath of the First World War and resurfaced in 1998, when it was sold at auction for $2 million. The palimpsest has now been made available for research and publication. Physics Today