# The Demotion That Saved the Object
> Seven Greek manuscripts were scraped clean in 1229 to make one prayerbook. The prayerbook is the only reason any of them survives. In this archive the longest gaps are often bridged by an object being valued as material.
> The Study - 2026-08-30
> Canonical HTML: https://iconotheca.com/study/the-demotion-that-saved-the-object/
## Key points
- A colophon on folio 1 verso of the Archimedes Palimpsest, deciphered under ultraviolet light by John Lowden in 2002, carries the date 13 April 1229. That is almost certainly the day the prayerbook was finished, and therefore the day the mathematics underneath it stopped being readable.
- At least seven manuscripts were scraped to make that one prayerbook, and the prayerbook is the reason the Archimedes text exists at all. A book of prayers was worth keeping in a monastic library for seven centuries. A treatise on floating bodies was not.
- The under text was not found by anyone looking for Archimedes. A. Papadopoulos-Kerameus catalogued the volume in 1899 and transcribed a few lines of the erased writing without knowing what it was; those lines reached Johan Ludvig Heiberg, who recognised Sphere and Cylinder and went to see the book in 1906.
- The Cantino planisphere of 1502 spent part of the nineteenth century as furniture. Henry Harrisse, writing in 1892, records it pasted onto the folds of a screen with its top margin cut off and thrown away, and recognised in that state in a Modena shop.
- A demotion preserves the substrate and destroys the evidence. The Archimedes diagrams survived because parchment was reused rather than discarded; the Cantino's top margin, which no imaging can recover, was cut off by someone making a screen.
## The commonest thing that carries an object through a long gap is a demotion
## The erasure of the Archimedes manuscript is dated to a single day in April 1229
## What the demotion cost, and what it bought
## The mathematics was found by a cataloguer who did not know what he had
## A world chart of 1502 spent part of the nineteenth century as a screen
## How to read a gap that ends in a reuse
## Why this archive is free to read
The instinct when a record shows an object being used as building material, furniture or blank parchment is to treat it as the low point of the story, a period of neglect between two periods of proper appreciation. That reading gets it backwards. Those are frequently the years the object was safest, and in the Archimedes case the demotion is not an interruption of the object's survival but the whole mechanism of it. What the demotion took was the evidence, and the evidence is not recoverable by imaging, funding or goodwill. So the honest thing a record can do is describe the alteration exactly, date it where a colophon or a cut edge allows, name who says so, and leave the missing margin missing.
## Questions
**What is a palimpsest?**
A palimpsest is a manuscript whose parchment has been scraped or washed clean of its original writing and then written on again. The earlier text is usually not fully removed, and ultraviolet and multispectral imaging can often recover it.
**When was the Archimedes Palimpsest erased?**
A colophon on folio 1 verso gives 13 April 1229, which is almost certainly the day the prayerbook written over the Archimedes text was finished. It was deciphered under ultraviolet light by John Lowden in 2002.
**Why does the Archimedes Palimpsest matter?**
It is the earliest surviving Archimedes manuscript by about four hundred years, and the unique source in Greek for On Floating Bodies. The Method and The Stomachion survive nowhere else in any language.
**Who discovered that the prayerbook contained Archimedes?**
A. Papadopoulos-Kerameus catalogued the volume in 1899 and transcribed a few lines of the erased text without identifying it. Johan Ludvig Heiberg recognised those lines as Archimedes and examined the book himself at the Metochion in 1906.
**Was the Cantino planisphere really used as a screen?**
Henry Harrisse, writing in 1892, records that it was pasted onto the folds of a screen with its top margin cut off, and recognised in that state in a shop in Modena. The Biblioteca Estense's catalogue confirms the surrounding chain but does not describe the screen.
## Sources
- [1] The Archimedes Palimpsest project, 'The History of the Archimedes Manuscript', on the tenth-century origin, the 13 April 1229 colophon read by John Lowden in 2002, the Jerusalem provenance of the prayerbook, the 1899 catalogue by A. Papadopoulos-Kerameus, Heiberg's 1906 examination, and the sale at Christie's New York on 29 October 1998 for USD 2,000,000.
- [2] Biblioteca Estense Universitaria, Modena, catalogue record for [Carta del Cantino], 1502, shelfmark C.G.A.2, giving the Este ownership from 1502 and the 1870 gift of Giuseppe Boni.
- [3] Henry Harrisse, The Discovery of North America (London and Paris, 1892), pp. 423-424, for the screen, the cut top margin, the 1859 theft from the ducal palace at Modena and the recognition of the chart in Giusti's shop in the Via Farini.
- [4] The Digital Walters, The Walters Art Museum, Baltimore, the institutional home of the Archimedes Palimpsest imaging and conservation programme.