CITY OF LONDON

You are in the section:
City of London > Services > Leisure and culture > Records and archives > News and events > Measuring Medieval Dirt

Measuring medieval dirt


Kathryn M. Rudy describes her fascinating research into how dirt on medieval manuscripts can give us clues about how they were read and used, and reveals how a visit to the Museum of Natural History in Boston inspired her work in this field:


Ms 1448, a 15th century Flemish Book of Hours Medieval manuscripts are written on parchment, which is very tough, much tougher than paper. For the last ten years or so, I have been writing about late medieval Books of Hours and prayer books, and I have noticed - in the course of studying approximately 700 manuscripts in more than 40 libraries - that the parchment carries signs of wear from the original users. Whereas paper would have disintegrated after a decade or more of hard use, parchment just grows darker and darker with increased handling. In many manuscripts, one can see exactly where the owner’s thumb had rested on the page while she held her book open. (Many medieval prayer book owners were women.) These thumb marks over time created dark areas, usually at the lower corner of the page.

Books of Hours contain multiple texts. People did not read their Books of Hours from cover to cover; rather, they read selections. My research is helping to reveal which selections they favoured. All Books of Hours contain a calendar, the Hours of the Virgin, the Penitential Psalms and litany of the saints, and the Vigil of the Dead. However, they might also contain all kinds of extra texts. In the century or so before the Protestant Reformation, book owners demanded prayers for which the reader would earn indulgences, that is, credits to be released from Purgatory years or even thousands of years early. I compiled hundreds of these indulgenced texts as part of a post-doctoral project I designed at the University of Utrecht. I noticed that these texts were often more worn - that is, darker with the users’ fingerprints - than other texts in the manuscript. I set out to discover if I could measure these varying degrees of use and handling to determine which parts of the manuscript were read and handled and which parts were ignored.

My first attempt involved photographing each folio of a manuscript, then lining up the photos from the folios with the lightest, most pristine margins, to the folios with the darkest margins, thereby ranking them according to use. This proved too expensive and time-intensive. A photographer named Casper Cammerat told me about the densitometer, an apparatus that measures the darkness of a reflecting surface. I experimented with this on the some of the heavily worn manuscripts at the Koninklijke Bibliotheek, where I was Curator of Illuminated Manuscripts from 2006 to 2009. 

To use the densitometer, I measured the “darkness” value for the thumbed area of every folio in a given manuscript. These values I entered in a spreadsheet, from which it was easy to generate a graph that would clearly show which parts of the book had been heavily handled and which parts had been relatively ignored.

Closeup of Ms 1448, a 15th century Flemish Book of Hours I analysed twelve manuscripts with this method, and the results showed some surprising trends. Many users read their Penitential Psalms more intensely than any other text. Several other graphs showed heavy usage at the Hours of the Virgin, but the graph often drops off at the end of this text, suggesting that people did not stay awake through compline to finish their devotions, but rather fell asleep before the part of the text that was supposed to be read late at night. The graphs often reveal spikes at the indulgenced texts. In some cases, the votaries read these indulgenced texts with such voracity that they rubbed the text right off the page. I suppose that they had memorised the texts in the course of inadvertently obliterating them.

I had learned about the idea of measuring wear as an index of usage when I was child in the 1970s and my mother took me to the Museum of Natural History in Boston. I vividly remember an exhibition of chicks hatching from eggs in a glass box, with heat lamps above to keep the emerging chicks warm. The box was about two meters squared, filled with maybe 100 eggs, all at different stages of hatching, and just the right height for children. One could not help rooting for the chicks as they struggled out of their shells. I stood there enraptured for an hour. Or was it three hours? I was absorbed.

Eventually the guard came over and gently shooed me away because the museum was about to close, and I was the last one remaining watching the chicks. He pointed out that the square of linoleum on which I had been standing was loose, and several other squares were new and had been recently replaced. “That’s how we know how many visitors look at each of the exhibits - by how often we have to replace the floor tiles,” he explained to me. This was my introduction to indirect evidence, which I have now applied to medieval manuscript research. I’ve always believed that some of the opportunities for creativity emerge when we apply the conceptual structure of one field to the material of a seemingly unrelated field.

I have also been fortunate to come from a family of inventors and writers. When I told my aunt, who is a paper chemist, what I was doing with the manuscripts, she found an old densitometer in the back office, which her company agreed to donate to my study. I am also grateful to my dedicated research assistant, Julia Brungs, who crunches my numbers and generates my graphs, as well as to the Caroline Villers Foundation, which supports my research at the Courtauld Institute. I have now measured the dirt in the Books of Hours in the Koninklijke Bibliotheek in The Hague, and have received invitations to do so at the Royal Library in Brussels, the Fitzwilliam Museum in Cambridge, the British Library, and now at Guildhall Library and LMA in London.


The images used in this article are from Ms 1448, a 15th century Flemish Book of Hours, made in Arnhem in the Netherlands for the use of the Diocese of Utrecht, one of the books Kathryn studied at Guildhall Library which is now available at LMA with prior notice.


Valid XHTML 1.0 Transitional