Conserving Ptolemy

By Lesa Dowd and Matthew Clarke

Among the treasures of the Newberry’s collection is Ayer MS 740, an extraordinary fifteenth-century handwritten copy of a seminal work of geography: Ptolemy’s treatise Cosmographia.

The book is as beautiful as it is historic—yet few would know. For until recently, Ayer MS 740 was inaccessible to researchers due to its extreme fragility.

Over the centuries, the degradation of the ink burned holes through the pages—a process known as “lacing."

To make matters worse, the book had been rebound too tightly by a previous binder, exacerbating the damage.

Because the costs of conservation were prohibitively high, Ayer MS 740 had been unavailable for decades.

But in 2017, a group of donors at the Newberry’s annual Booked for the Evening event agreed to fund the repair and digitization of the manuscript. With their generous support, our conservation team (Lesa Dowd, Leith Calcote, Henry Harris, Kasie Janssen, and Virginia Meredith) was able to mend the book’s deteriorating pages and prepare the manuscript for digitization. In what follows, we take you step-by-step through the conservation process.

When it arrived in the Newberry’s conservation lab, Ayer MS 740 was encased in a beautiful nineteenth-century binding—but one so tight that it had restricted the opening and hastened the deterioration of the book.

As a first step, conservators disbound the book, separating its boards, peeling away the spine leather, and scraping off its paper spine linings:

Next, they separated the book’s sections by cutting the sewing threads, removing sewing cords, and carefully detaching each gathering of pages:

Once the manuscript was entirely disbound, conservators could examine the ink on the pages. They tested the ink for solubility in water and alcohol, as well as for the presence of corrosive chemical agents.

Conservators had begun the project hoping to use a water-based treatment to stop the destructive acids in the ink from causing any more damage. However, after examining the ink, they decided against the water-based option. Instead, they chose to stabilize the book’s pages to prevent further deterioration. To do this, they applied thin tissue paper to deteriorating pages using a custom-made adhesive. These tissue papers are designed to stabilize pages and prevent further lacing:

As a result, Newberry conservators were able to mend the pages where letters had begun to lace through the paper, while also forestalling further degradation throughout the book:

Conservators then rebound the book, sewing individual sections on to raised cords and lining the new spine with tissue and linen.

Finally, they encased the re-sewn sections in a period-appropriate, semi-limp paper binding and placed the repaired book in a custom-made, cloth-covered drop spine box, where it now lives in the stacks, with the rest of the Newberry collection.

Lesa Dowd is Director of Conservation and Matthew Clarke is Communications Coordinator at the Newberry.

Support for the conservation of Cosmographia was provided by Mark and Meg Hausberg, Victoria J. Herget and Robert K. Parsons, and Nancy and Richard Spain.