Conquering the Dreaded Red Rot

 

Throughout the Past Caring Project we’ve often mentioned the term red rot as a major part of the collection’s conservation issues. As I’ve recently completed consolidating one hundred degraded leather bindings of the Poor Law Union and Workhouse collection, it feels like a great time to write a post on the topic.

However foreboding the name, red rot is a fairly common type of leather degradation that most often occurs in bindings from the late industrial revolution onwards. Leather, like all organic material, breaks down and degrades over time. However, due to changes in the manufacturing process of leathers during the 19th century, the material from this time period is often in poorer condition than earlier leathers. On red rotted bindings, the leather is fragile and weak, often splitting, cracking, and coming off the binding at the joints, corners and top and bottom of books. The leather is also easily abraded and scratched. In its poorest states, simply placing the book on a work surface causes powdery leather fibres to fall off. Over half of the books of the Poor Law Union and Workhouse have this kind of degradation, with 300 large Minute Books and Ledger  bindings that are damaged enough to require a conservation treatment.

Fun with a microscope!

For a visual comparison, I took two small fibre samples from new and red rotted leather to photograph under a microscope. These fibres were gently scraped with the back of a scalpel from the flesh side of the leathers (the side without the grain).

Leather fibre samples

New leather sample (left) and historic sample (right).

The sample on the left was taken from a new piece of archival quality leather; the fibres were reluctant to come apart during sampling. The sample on the right was taken from the inside of an 1846 Minute Book and was noticeably easier to tease apart.

Samples at 55x magnification: new leather (L), red rotted leather (R).

Samples at 200x magnification

Under magnification, the fibres from the new leather are longer and more cohesive, which gives strength and durability to the leather. The shorter, less cohesive fibres of the Minute Book is why the leather on the latter binding is fragile, easily abraded and ends up all over hands and clothes during handling.

What changed during the industrial revolution? Why is it called red rot?

To transform animal skin (most commonly calf, sheep, goat, and pig in the UK) into bookbinding leather, the skin must go through a chemical process called tanning, which makes the skins resistant to putrefaction and decay. During this process, the animal skin (which is previously  prepared by removing hair and flesh) is submerged in the tanning liquor- an astringent liquid made from leaves, twigs, wood and bark of plants (two examples are sumac and chestnut). The tanning liquor attaches and coats the fibres of the skin, preserving it in a way that creates flexibility and malleability while resisting biological attack. After this, the leather is dyed and ‘finished’ to create the final product. This process can take several months or more.

Leather tanning from Diderot's Encyclopaedia

Engraving of leather tanning from Diderot’s Encyclopaedia. (Link for more images of leather processes here). Image: public domain

As demand for leathers increased in the late 18th and 19th C, leather makers began using more astringent plant matter (such as Hemlock and Gambier) to speed up the tanning process. These quicker tans have a slightly different chemical makeup and result in leathers more susceptible to absorbing pollutants from the atmosphere- which plays a large role in its deterioration. Once absorbed, the pollutants react with the tannin and become acidic, which increases the rate that the leather fibres break and degrade, reducing its strength. These speedier tannins also react with light to create the characteristic red and oranges tones of red rot, while poor storage conditions exacerbates deterioration.

What are we doing to help?

While there is no way to fully halt or reverse red rot, one of the main goals of the Past Caring project is to slow the rate of degradation and enable readers to access the volumes without causing further physical damage to the items. We also aim to reduce the amount of powdery leather deposits that gets on the users, tracks through the bindings, and are potentially inhaled during use.

With the above goals in mind, we chose a two step approach: first treating the leather with a very light consolidant (adhesive) to prevent the leather fibres from coming off the binding, then creating a user friendly cover to minimise the amount of abrasion and direct contact with the leather during use.

Consolidant testing

Initial testing of the consolidant at different concentrations.

The leather consolidant is a mixture of Klucel G© (a light adhesive with proven longevity) which is dissolved in an isopropanol (a purified version of rubbing alcohol). The consolidant mixture was chosen because it did not blacken or significantly darken the leather, which retained the binding’s original appearance, while being a relatively benign treatment in the long term. The consolidant is gently applied with a large brush and after it is dried, a bespoke cover made from archival polyester is created to protect the binding. We chose polyester as it is smoother and less abrasive than a card cover, while enabling the spine or any label markings to be viewed on the binding. The bindings are then housed horizontally in low-acid archival boxes which will help to protect the bindings from any environmental or physical damage, while absorbing excess acidity.

Phew, only 200 more bindings to go!

Thank you for reading! Please feel free to leave a message below or email me at tiffany.moore[@]exploreyork.org.uk for with any questions or comments.

Tiffany

 

 

Sources

Kite, M., & Thompson, R. (2008). Conservation of leather and related materials. Oxford, Burlington, MA.

Larsen, R., & Vest, M. (1994). STEP leather project: evaluation of the correlation between natural and artificial ageing of vegetable tanned leather and determination of parameters for standardization of an artificial ageing method. København, Royal Danish Academy of Fine Arts, School of Conservation.

Roberts, M. T., & Etherington, D. Vegetable Tannins. Bookbinding and the conservation of books: a dictionary of descriptive terminology. Online edition. http://cool.conservation-us.org/don//. [Accessed 05.08.2017].

Vidler, K. (2014). ‘Collagens and Tannins in Bookbinding Leather’. Conservation of Leather Bindings. West Dean College. Unpublished.

Vidler, K. (2014). ‘Common Types of Bookbinding Leather Deterioration’. Conservation of Leather Bindings. West Dean College. Unpublished.

 

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Improving York one street at a time

York’s City Commissioners (aka the Improvement Commissioners)

Many of you may not be familiar with York’s City Commissioners, a group of officials who had the unenviable task of improving the condition of York’s streets in the first half of the nineteenth century. At the moment I am working on the catalogue for their records and thought it would be a good opportunity to tell you a bit about their role in the history of York’s urban development.

York’s City Commissioners came into being with an Act of parliament in 1825. By the 1820s many of the city’s inhabitants had become disgruntled with York Corporation, which was seen as corrupt and ineffective. With a growing population, the medieval and Georgian streets of York were badly in need of attention and investment, neither of which was forthcoming from the civic officials.  However, public pressure resulted in the York Improvement Act of 1825. The Act allowed for 40 Commissioners to be elected, forming a local board with separate and independent powers to that of York Corporation. The autonomy of the board was significant for two reasons: first, non-conformists, such as members of the Society of Friends (Quakers), were eligible to become Commissioners at a time when they were barred from taking civic office in York; second, many considered the Corporation too corrupt to be trusted with the duties outlined in the Improvement Act.  In theory therefore the new City Commissioners were able to act outside of what many believed was a broken system.

York was not the only town in England faced with an inefficient or inadequate form of local government during this period. Over the course of the eighteenth and nineteenth centuries, hundreds of acts were passed through Parliament, each specific to a particular town. And these ad hoc boards were charged with carrying out improvements in urban centres where the local authority was unable or unwilling to do the job.

Who were the City Commissioners?

To be eligible for election, prospective commissioners needed only to satisfy a property qualification, which was the possession of land or property with an annual value of £10 or more. Many of the Commissioners were local businessmen and tradesmen who had a vested interest in improving York’s streets.

Members of York’s Quaker community were quick to seize the opportunity to make an active contribution to the development of the city. The handbill below shows a list of commissioners that includes the names Daniel Tuke, James Backhouse and Thomas Terry, who were all from prominent Quaker families.

List of elected Commissioners c1830

List of elected Commissioners c1830

What did they do?

When the York Improvement Act came into force in 1826, it granted the Commissioners authority over street cleaning and public nuisances, paving, lighting, and some policing. For the first time, there was an authority that had responsibility for cleaning the streets and yards of the poorer areas of York. In order to fund these improvements the Commissioners were granted the power to levy rates, although the amount they could impose was limited. As elected officials, it was also their job to respond to complaints from individuals and communities regarding specific streets in York. The document below shows a signed petition (or memorial) from some of York’s ratepayers complaining about the street of Hungate in 1839. I have also transcribed some extracts from this petition, which you can read at the end of the blog.

Signatures of ratepayers on a petition to the City Commissioners, 1839

Looking at the papers and minutes of the Commissioners, it is clear that they made a concerted attempt to make York’s streets cleaner and safer. Many areas were paved and some streets were macadamised, a system of laying a compacted surface of small stones that was pioneered by John McAdam in 1820; the Commissioners were also responsible for instituting the first nightwatch in York.  But their work was curtailed for various reasons. Overlapping jurisdictions with the Corporation led to frequent disputes, and the differing makeup of each body only exacerbated these quarrels. In addition, the Commissioners were severely underfunded yet unable to increase their income owing to the restrictions on the rates they could collect. Further limitations were placed on what they could achieve as gas and water supplies were still controlled by private companies.

In 1835, York Corporation was reformed under the Municipal Corporations Act of the same year. In the years that followed many of the concerns that led to the passing of the Improvement Act were addressed by the new civic organisation. The Commissioners were eventually wound up in 1850 and their responsibilities transferred in part to the newly established Local Board of Health and in part to the now reformed York Corporation.

What kinds of records did they create?

Voucher bundles MI8

Bundles of vouchers (1840s)

Around eight boxes of records for the City Commissioners survive. They include minutes of meetings; correspondence; financial papers, which include quite a large number of vouchers (what we would call receipts today); election papers; as well as papers relating to streets, drainage and lighting. Some of the documents are still in their original bundles, as you can see in the image to the left.

Legacy

While the City Commissioners may not have brought about a transformation of York’s streets, their work nevertheless signals a key period in the history of England’s urban centres – one that witnessed a move towards more regulated and planned approaches to development.  Importantly, they also show how York’s built environment  has been shaped by an ongoing process of negotiation between York’s officials and the people of the city.

Extracts from petition of 1839

To the Commissioners under the York Improvement Act

That your memorialists have suffered considerable inconvenience and danger in passing along the street of Hungate, in consequence of its very narrow width at the upper end, adjoining St Saviourgate, where it is with the greatest difficulty that on Marketdays and on frequent other occasions foot passengers can proceed, from the continual passing of carts and the danger of being crushed to death, the entire width of the street at the part opposite the Church Yard being only 10 feet 3 inches from wall to wall

That the great bulk of your memorialists are engaged in daily labour to provide by honest industry for the maintenance of their families, and that in going to and returning from their work they are necessitated to pass along the street of Hungate several times every day, that being the principal way to the centre of the City.

That the memorialists have contributed to the rates of the City Commissioners with great cheerfulness , although many have not derived any benefit from paving or draining near their respective dwellings, and therefore have a stronger claim on the consideration of the Board of Commissioners’

Sources: Victoria County History of York; Papers of York’s City Commissioners