It is believed that Archimedes, who lived from 287 to 212 BC, originally wrote his theorems on papyrus scrolls. To preserve this knowledge, these were probably copied and recopied on papyrus until about the 4th century AD — when parchment and the ‘book' were adopted. From that time on they were likely copied and recopied onto parchment. The Archimedes Palimpsest contains the oldest known copies of any of his theorems. It includes the only copy of the treatise on the "Method of Mechanical Theorems" and the only copy in the original Greek of the treatise "On Floating Bodies."

The theorems that were copied onto this manuscript in the 10th century did not survive the next millennia unscathed; they were scraped off during the 12th century so that the parchment could be reused. At that time the leaves of the book were cut and turned, prayers were written on top of the scraped-off text, and the book was rebound in a smaller format. The resulting Euchologian (or prayer book) was an important tome and the parchment was never scraped off and overwritten again.

For the next 600 years the prayer book likely remained in the Monastery of Mar Saba in the Holy Land (between Bethlehem and the Dead Sea, in what is now Israel), in constant use by the monks. It was removed from this monastery in the middle of the 19th century and eventually arrived in Constantinople (Istanbul). In 1906, Danish philologist Johan Ludwig Heiberg discovered that it contained Archimedes' theorems and transcribed them using a magnifying glass (although some of the text was concealed by the binding). By 1930 the prayer book was in a private collection in Paris, where it resided until 1998 when it was purchased by an anonymous buyer for $2 million.

Scott Williams examines one folio of the Archimedes Palimpsest through a stereomicroscope.

While viewing the palimpsest through a stereomicroscope, Scott takes a sample of adhesive using a scalpel.

The new owner graciously agreed to have the manuscript conserved and made available to Archimedes scholars for transcription. But first it had to be taken apart. Responsibility for this work and the conservation treatment was given to the Walters Art Museum in Baltimore, MD.

A team of scientists from the Rochester Institute of Technology, the Xerox Corporation, and the Johns Hopkins University in Baltimore was assembled to enhance the Archimedes text, which is very faint and difficult to see. The team is accomplishing their task with the help of ultraviolet imaging, confocal microscopy, and several techniques that have been used to obtain satellite images of the earth.

During its life the palimpsest had survived a fire (as evidenced by the charred edges of the manuscript), developed a severe problem with mould, and been taken apart and rebound using a modern adhesive. Its conservation treatment and disbinding for transcription promised to be a complex process. As part of the procedure, CCI was contracted to provide analytical support and materials expertise.

CCI scientists travelled to Baltimore in November 2000 to examine the palimpsest and take numerous samples of the parchment, inks, adhesives, accretions, residues, and mould. These samples were brought back to CCI for analysis.

To determine the state of deterioration of the parchment, samples from healthy areas, charred and mouldy areas, and the area of staining from the Archimedes inks were subjected to shrinkage temperature measurements using a new video technique to determine onset and end-point temperatures (shrinkage temperature has been shown to correlate to the level of deterioration of collagen fibres). Samples of 10th- and 12th-century ink were identified mainly as iron gall, although other inks were also found to be present. Mould samples were assessed for viability to determine whether or not the mould posed a future danger to the object and/or its handlers.

Various adhesives, accretions, and residues (such as silica gel, candle wax, and a modern adhesive on the spine binding) were identified. The presence of the modern adhesive was problematic because it was in direct contact with the Archimedes text. Two innovations were utilized to find a solvent system that would remove the adhesive without damaging the parchment. First, a new micro-swell test was devised to identify the most effective solvent removal system for the adhesive. Second, the solvent system was tested on micro-quantities of parchment and shrinkage temperature measurements were taken to determine whether or not it was dangerous to the parchment.

This project is an example of the comprehensive analysis of a manuscript that CCI can undertake to assist conservators in the conservation of historically important documents. As a result of these analyses, specific identifications, assessments, and recommendations were made and some innovative scientific techniques were developed to assist in the conservation treatment and disbinding of the Archimedes Palimpsest.³ This work is not yet complete, and CCI will continue to assist the Walters Art Museum with further analyses and advice as required.

The Archimedes text that has been newly revealed has already provided scholars with new information about the great mathematician/physicist. For example, a leaf containing part of the "Method of Mechanical Theorems" indicates that Archimedes knew of and used calculus 2000 years before Newton is credited with its discovery.⁴ Who knows what other discoveries lay in store as more text is revealed?

Further information on the Archimedes Palimpsest can be found on the Web site of the Walters Art Museum.

1. This article was prepared with the assistance of other CCI scientists who worked on the project, including Gregory S. Young, R. Scott Williams, Jane Sirois, Elizabeth Moffatt, and Maureen A. MacDonald.
2. A palimpsest is literally ‘a piece of parchment or other writing material from which one text has been erased to make room for another' (a process that could be repeated numerous times). The practice of reusing parchment was quite common at various times in history, and there are many palimpsests in existence today. The Archimedes Palimpsest is valuable because of what it contains.
3. The results of these analyses are the subject of a paper to be presented at the annual congress of the International Institute for Conservation of Historic and Artistic Works in Baltimore, MD, in the fall of 2002.
4. Peakin, W. "The Sum of God." The Sunday Times Magazine (June 17, 2001), London, UK.