In current conservation practice, where minimal intervention is favoured, it is unusual to decide to disbind a book entirely. However, in the case of the Chester Beatty Library’s rare complete copy of Katib Çelebi’s Cihan-numa (Mirror of the World, CBL AA 306) it was decided that this was the best option in order to carry out a comprehensive conservation treatment of the damaged text block. The Cihan-numa was printed by Ibrahim Müteferrika in Constantinople in 1732, and summarised Ottoman geographical knowledge of the time. It was one of the first texts to be published by Müteferrika, founder of the first official Ottoman printing house in Turkey.
The book first came to the attention of the conservation department in 2016 when an image of a double folio map was requested for inclusion in the Director’s Choice publication. Due to the restrictive 19th century binding and modern European sewing structure, the opening of the text block was extremely restricted. The text block was already detached from the case binding, and digitisation of the printed map was not possible in situ. In order to facilitate digitisation, the map was removed from the damaged text block so that it could be fully repaired by previous Heritage Council Intern Cécilia Duminuco before digitisation.
It was at this point that I was given the project to work on. One of the most significant factors contributing to the decision to take the text block apart into quires was to allow for complete repair. In particular, the green colour used to paint the frame lines around many of the printed maps had gradually burnt through the paper causing most of the folios to split along this line. Resewing the folios in a more sympathetic style would release the strain on the heavily burnished paper of the text block and reduce the risk of any additional breakage in the areas that were decorated with this copper-containing pigment. Using a traditional Islamic sewing style would also be less restrictive than the heavily glued-up 19th century structure, increasing the opening of the text block and allowing the folios to be viewed right into the gutter edge.
While taking apart the text block every detail that could provide information about the original sewing structure was recorded. In the middle of most quires remnants of a pink or red sewing thread and previous sewing stations could be recorded.
It was also apparent that the text block had not been completely resewn, as previously thought. Instead the back of the text block was sawn into at nine stations and cords were embedded inside these recesses over the previous sewing structure. After which a generous amount of glue was applied before gauze and paper linings were added by the 19th century binder. This treatment ensured the quires would stay together, but also restricted the movement of either the sewing threads, or the heavily burnished paper.
The gauze and paper backings and the proteinaceous glue were removed manually with a scalpel in order to avoid distorting the highly water sensitive paper with moisture from a poultice. After removing the glue, the quires were separated from each other. Although there was no glue holding the quires together anymore, they did not separate very easily- especially where the paper was sawn into. Great care was necessary to avoid further damage to the paper in those areas. While separating the quires a collation map was prepared in order to chronicle the sewing structure, but which was also used to record any common traits or unusual details found during the process of disbinding. The collation map includes notes of the folios with hand coloured maps, the location of annotations made by someone studying the text in the past, as well as specific damages such as old repairs, damage by insects and copper corrosion.
After separating the folios they were put into tissue folders and placed in temporary storage boxes to await their paper repairs. The paper repairs are now well underway and will be the focus of a future blog post towards the end of the year.
Dorothea Müller, Heritage Council Intern in Conservation
Dorothea will give a talk about this project as part of Heritage Week in August 2017. Her presentation will take place in the Lecture Room at the Chester Beatty Library, at 1.10pm on Thursday 24th August.