Collection Care blog

53 posts categorized "Research"

21 October 2014

Paper cuts: small but mighty!

Hardly noticeable and barely bleeding, paper cuts are the mother of all library injuries. Anyone who deals with paper on a daily basis will have at some point suffered such an affliction. Paper cuts cause a seemingly out of proportion amount of pain due to the anatomy of our skin and the structure of paper. When very thin and held in place, a sheet of paper becomes inflexible and can exert very high levels of pressure – enough to slice through flesh! Yikes! Let’s go under the microscope to see what's happening...

An edge of a single sheet of paper, with the rest of the piece of paper blurred out and against a black background.

Figure 1: A single sheet of paper at x30 magnification.

A finger with a paper cut against a black background.

Figure 2: Paper cuts - small but mighty!

Most paper cuts result from new sheets of paper held strongly in place. A rogue sheet may come loose from the pack but remain held in position by the rest of the tightly-knit sheets. In paper, more resistance is felt when a force is applied parallel to a sheet of paper. This has to do with the paper’s tensile strength. Tensile strength measures the ability of a material to resist rupture when force is applied to one of its sides under certain conditions. Held in place, the sheet of paper becomes extremely resistant to buckling, stiffens, and acts as a razor.

The edges of a stack of paper with one sheet, about halfway down, sticking out from the stack.

Figure 3: A sheet of paper that strays from the pack can cause serious paper cuts!

A paper’s edge may appear to be smooth and flat, but on a microscopic scale paper edges are jagged. Paper cuts leave a wound more like one from a saw than a knife (a miniature papery saw).

The edges of pages of a book, looking quite sharp.

Figure 4: Pages from a copy book at x30 magnification. Fibres at the surface give paper a serrated edge. The black lines are page lines.

Paper cuts are remarkably painful. They usually occur in the fingertips, which have a greater concentration of nerve cells (neurons) than the rest of the body – an evolutionary trait to protect us during the exploration of our environment. Neurons send chemical and electrical signals to our brain, and some of them, called nociceptors, detect potential harm. Paper cuts stimulate a large number of nociceptors in a very small area of the skin. Shallow paper cuts don’t bleed very much so pain receptors are left open to the air resulting in continuous pain as the wound cannot clot and seal. As we continue to use our hands, the wound flexes open, continually distressing these neurons.

Not only do paper cuts part the flesh with a micro-serrated paper edge, but they also damage skin either side of the wound due to the composition of the paper. Pain receptors are continuously irritated by the combination of cellulosic wood pulp, rags, grasses, chemically-coated fibres, and bacteria that make up paper. Paper may also include other additives such as chalk or china clay to make the paper easier to write on. Sizing gives us a great variety of papers to suit the specific type of ink we wish to apply, but involves mixing many additives into the pulp to determine the correct surface absorbency.

Paper cuts from envelopes can be particularly stingy due to the layer of glue along the sealing tab. The glue is made from gum arabic, which although edible to humans, can pack a punch if embedded inside a wound. Gum arabic is the product of hardened sap taken from two species of acacia trees, and is also used as a binder for watercolour painting, and in traditional lithography.

Magnified, adhesive on an envelope looks shiny and jelly-like.

Figure 5: Gum arabic glue at x30 magnification coats the paper tab on an envelope.

A close up of an envelope tab with adhesive.

Figure 6: Gum arabic glue at x200 magnification coats the paper tab on an envelope. When the gum is moistened it forms a seal with the adjacent paper.

When skin closes around the paper cut these foreign particles become trapped inside causing a great deal of pain. This is why a cut from a razor blade is usually less painful than that from a paper cut: razor blades make clean incisions without leaving behind any foreign particles. It hurts initially, but the pain soon ebbs away. Bleeding caused by a razor cut helps to wash away any infection-causing particles, while paper cuts bleed very little (this also reduces your chances of getting any sympathy!)

Three blades of a razor are shown at close up, showing sharp edges.

Figure 7: A razor blade at x50 magnification.

The sharp and smooth edge of the razor is even more apparent at high magnification.

Figure 8: A razor blade at x200 magnification. The razor’s edge is smooth allowing a clean incision without introducing foreign bodies.

It might seem strange that sometimes needles for a flu jab require quite a bit of force to pierce the skin, yet paper (PAPER!) can slice through. This is due to the random orientation of collagen fibres in our skin allowing us to withstand pinpoint forces.

The tip of a finger is being poked by a needle.

Figure 9: Human skin feeling the pressure under a sharp pin (x20 magnification).

Our skin does not have a comparable strength against shearing forces such as those exerted by paper, and so, we are susceptible to the small but mighty paper cut. Libraries can be dangerous places. Be careful out there!

Christina Duffy (@DuffyChristina)

 

Further learning:

Paper May Be the Unkindest Cut, Scientific American, Volume 306, Issue 3 , Mar 1, 2012 |By Steve Mirsky 

Why Do Paper Cuts Hurt So Much? Scientific American - Instant Egghead #25

 

09 October 2014

Burnt Cotton Collection survey enables digitisation prioritisation

With the recent multispectral imaging of the burnt Magna Carta hitting the headlines following our blog post on the 800 year old Magna Carta revealing its secrets, there has been a lot of interest in the conservation work required to protect such items. The so-called “burnt” Magna Carta (Cotton charter xiii 31a) suffered fire damage in Ashburnham House in Westminster on 23 October 1731. This 1215 exemplification formed part of an exquisite library assembled by English antiquarian Sir Robert Cotton during his lifetime (1571-1631). Cotton’s library forms the basis of our collections at the British Library today, and a recent conservation survey of the burnt material has allowed us to categorise items based on their relative condition, enabling us to immediately identify items suitable for digitisation. This has vastly improved our workflow allowing digital access to a wider audience in a shorter time. 

This piece includes material from an article published by Taylor & Francis Group in Journal of the Institute of Conservation on 29 November 2013, available online at: http://www.tandfonline.com/doi/abs/10.1080/19455224.2013.815122#.VFDzZvmsWtB.

You can see the Magna Carta is suffering from fire damage--the parchment is burnt, discoloured, and the text appears unreadable. You can see the seal hanging from the bottom of the parchment.

A close-up of the disfigured wax seal. The seal rests in a mount which is cut just bigger than its shape--this keeps it in place and secure.
The burnt 1215 Magna Carta suffered fire damage and subsequent interventive treatment. The vulnerable wax seal of the charter melted and distorted in the intense heat. 

CC by 

In the Ashburnham House fire a quarter of the manuscripts were either damaged or destroyed in the blaze, and attempts to extinguish it exacerbated that damage. The documents suffered shrinkage and distortion, bindings were carbonised, ink was lost, soot and dirt was ingrained, tide marks formed on the leaves, and parchment (animal skin) gelatinised. Gelatine is the brownish end-product of a rapid degradation of parchment collagen. Remedial work caused further damage with many of the manuscripts broken up and rebound during salvage. Incorrect reassembly impacted on the codicological history of many of the manuscripts. The darkened gelatinous material which formed along the edge of the parchment was trimmed away from some manuscripts. Unidentified fragments were gathered and put into drawers.

The collection was untouched until the establishment of the British Museum in 1753, where over the coming years invasive treatments were recorded. To separate the leaves which had glued together by gelatinisation, about 40 manuscripts were immersed in a hot aqueous solution (likely to be ethanol in water). Incisions along the parchment edges were made to allow the leaves to dry flat under pressure. Despite the efforts, leaves remained brittle and fragile. Inlaying of parchment fragments into paper was completed in 1856, but a huge number of fragments remained loose and unidentified. While the edges of loose fragments were protected by this inlaying method, over time the degradation of materials caused further concern. The brittle fragments were susceptible to break with every page turn, and acidic paper in heavy volumes tended to cockle preventing the volumes from closing.

The volume rests open, with the left side being supported by a foam wedge and the pages held open with a snake weight on the left side. The burnt parchment pages have been adhered to a tan paper, and all pages rebound.
Cotton Tiberius A. XII. Parchment fragments were attached to paper in the nineteenth century and incisions were cut along the sides to allow the leaves to lay flat.

CC by 

Our conservators surveyed 243 items from the Cotton Collection, including 21 paper manuscripts. Items were graded on their physical, chemical and overall conditions based on an assessment of the state of the binding and parchment substrate, and thus rated for treatment priority.

A bar graph showing different characteristics (active mould, old repairs, staining, etc.) and the percentage of items with that characteristic.
Results of the survey of 243 Cotton Collection volumes. From Figure 2 and 5 in The conservation of the burnt Cotton Collection in the Journal of the Institute of Conservation, 2013
A pie chart showing different grades of damage, from Uniform Good Condition (A) to High Degree of Damage (E).
Pattern of damage where D (High degree of damage) accounts for 61% of the total items examined. From Figure 2 and 5 in The conservation of the burnt Cotton Collection in the Journal of the Institute of Conservation, 2013.

CC by 

The nineteenth century treatments have been fundamental to the preservation of the Cotton Collection, and many items thought to be lost have since been rediscovered. The condition survey enabled us to quantify the damage and develop a strategy for the long-term preservation of the burnt Cotton Collection. Items identified as being fragile were immediately withdrawn from library use, while research to determine the best methods of stabilising and housing the items was undertaken. The use of analytical techniques such as near-infrared (NIR) spectroscopy for assessing the deterioration or parchment has enabled a better awareness of the nature and condition of these manuscripts. This information has helped to support the choice and realistic scope of conservation methods. In the case of the burnt Cotton Collection, the future project is now directed towards a preservation approach, including digitisiation and multispectral imaging, rather than an interventive conservation one.

Christina Duffy (@DuffyChristina), Imaging Scientist

 

Further reading

The conservation of the burnt Cotton Collection, Mariluz Beltran de Guevara and Paul Garside, Journal of the Institute of Conservation, 2013. Vol. 36, No. 2, 145 –161, http://dx.doi.org/10.1080/19455224.2013.815122

Collection Care fired up for BBC Four appearance, Christina Duffy: http://britishlibrary.typepad.co.uk/collectioncare/2013/08/collection-care-fired-up-for-bbc-four-appearance.html

Crisp as a Poppadom, Ann Tomalak: http://britishlibrary.typepad.co.uk/digitisedmanuscripts/2013/02/crisp-as-a-poppadom.html

‘Their Present Miserable State of Cremation' the Restoration of the Cotton Library, Andrew Prescott: http://www.uky.edu/~kiernan/eBeo_archives/articles90s/ajp-pms.htm

07 October 2014

800 year old Magna Carta manuscript reveals its secrets

Ground-breaking multispectral imaging work of the British Library’s burnt copy of the 1215 Magna Carta has recovered text which has not been read in 250 years.

This work has been completed by British Library conservators and scientists in preparation for next year’s 800th anniversary of the sealing of the Magna Carta. The so-called ‘burnt’ copy of the Magna Carta is one of four original manuscripts from 1215 which survive. In February 2015, the four manuscripts will be brought together for the first time in history for a special 3-day event, which will allow further academic study of them side by side, as well as the once-in-a-lifetime opportunity for 1,215 people to view them together.

Megavision multispectral imaging camera with Magna Carta.  A multispectral colour image of a section of Magna Carta showing loss of legibility.

A processed image of the charter revealing text thought to be lost forever.

Figure 1: Top left: The “Burnt Magna Carta” ready for multispectral imaging. Top right: A real colour image of a section of the charter. Bottom: A processed image of the charter enhanced to reveal text thought to be lost.

The British Library owns two of the original 1215 Magna Carta manuscripts (the other two are held at Lincoln and Salisbury Cathedrals). The story of the ‘Burnt Magna Carta’ (Cotton charter xiii 31a) held in our collections is a truly remarkable one of survival against all the odds. In 1731 it was damaged in the Cotton Library fire, and subsequently staff at the British Museum Library used 19th century techniques to try to flatten and mount it, which has contributed to its current condition today rendering the text very difficult to see.

The multispectral imaging of the burnt Magna Carta was conducted as part of a major project involving the reframing and scientific analysis of all the Magna Carta charters held in our collections ahead of the 2015 anniversary. The Collection Care team provided an initial examination of the original frames to determine their structure and composition. All original mounting materials in contact with the charters were tested using infrared spectroscopy, pH tests, and lignin tests to determine their stability and compatibility with new materials. Once the charters were removed from the frames, near-infrared spectroscopy and high resolution digital microscopy was used to investigate the condition of the ink and parchment as part of the overall condition assessment.

With the frames and glass removed there was a rare opportunity to employ the cutting-edge technique of multispectral imaging enabling us to virtually peel away the layers of damage currently affecting the manuscript.

Conservator Kumiko Matsuoka Conservation Scientist Dr Paul Garside

Conservator Gavin Moorhead Imaging Scientist Dr Christina Duffy
Figure 2: Clockwise from top: Temporary housing is prepared to store the charter when removed from the frame; the original wooden frames are removed to enable access to the charter; the charter is released from the mounting; once the charter is free from the frame it can undergo condition assessment.

The "Burnt Magna Carta" also known as Cotton charter xiii 31a.  A microscopy image showing detail of iron gall ink loss.

Figure 3: Left: The “burnt” copy of the Magna Carta, Cotton charter xiii 31a, is one of the four original manuscripts from 1215 which survive. Right: Much of the ink has been lost with only a few remaining initials (shown here at 50x magnification).

Multispectral imaging is a non-destructive, non-invasive imaging technique using different colour lights, including ultra-violet and infrared, to recover faded and lost text. A high-resolution camera is securely mounted directly over the charter, which is then illuminated with LED lights ranging from the ultraviolet at a wavelength of 365 nm, through the visible region, and right up to a wavelength of 1050 nm in the infrared region. The chemical composition of the material in the charter is varied (ink, parchment, etc.), and so reacts differently to the lights. We are able to see, and capture, additional information undetectable by the human eye.

Figure 4:  An animated gif comparing the original colour and processed images. 

Ultra-violet colour image created by combining three captured images (UV light with R, G, and B filters).

Figure 5: A colour UV image reveals regions of text which are completely faded to the naked eye.

Using this technology and expertise available to us in the 21st century, we are able to preserve the Magna Carta for the next 800 years and present these iconic documents in the best possible condition for visitors who come to see them during the anniversary year.

Multispectral data is still being processed and will be published along with other scientific data collected after the British Library’s exhibition ‘Magna Carta: Law, Liberty, Legacy’, which runs from 13 March – 1 September 2015.

 

Christina Duffy (@DuffyChristina), Imaging Scientist

19 August 2014

Eighteenth-century Country-house Guidebooks: Tools for Interpretation and Souvenirs

A print of Wilton House, showing a large home surrounded by grass and trees. The print is in colour.
J. Buckler, South East View of Wilton House, 1810. (Yale Center for British Art, Paul Mellon Collection)

During the eighteenth and early-nineteenth centuries, country houses in Britain emerged as significant tourist attractions. There was already a long tradition of expecting country houses to offer travellers hospitality, and by the middle of the eighteenth century, part of being a polite landowner was allowing tourists to visit your house and grounds. In theory, this standard applied to all houses, but only a handful, such as Wilton House (Wiltshire), were sites which routinely attracted hundreds of visitors. At houses like these, the huge increase in visitor numbers led to formal opening hours, standardized tours (typically given by housekeepers), inns which catered to tourists and the publication of guidebooks. The guidebooks published during this period are the best records of what an ideal visit to a house was intended to be like: they indicate what you were expected to appreciate and to ignore. Guidebooks were typically published only after a house had established itself as a popular site, and so in effect, they codified visiting practices that were already in place.

Plans from A Guide to Burghley: a series of rooms are outlined and numbered.
Illustration from Thomas Blore, A Guide to Burghley [abridged version], Stamford: John Drakard, 1815. (British Library, 10358.ccc.3)



Guidebooks’ content was typically organized to maximize convenience for visitors as they toured a property. This is a set of schematic plans which was bound near the beginning of one of the Burghley House (Lincolnshire) guidebooks, and these plans are numbered according to the order tourists typically viewed rooms in – beginning with the great hall, room 1, then the saloon, room 2, and so on – they are linked to a key, but the numbering is also linked to the subheadings in the text itself. Not all guidebooks were illustrated in this way, but a room-by-room organization was common, presumably because this made it easier to carry, read and view at the same time.

In this colour print, two boats meet on a lake which is surrounded by greenery. It appears to be nearing sunset with the cloud-filled sky shifting from blue in the top left toward pink in the top right.
John Emes, The Lake, Hawkstone Park, Shropshire, 1790. (Yale Center for British Art, Paul Mellon Collection)



Guidebooks had tremendous potential as interpretive tools in that they could make a site more accessible and legible to its visitors. One of the main reasons people published guidebooks was to catalogue the art collections: this was not only a gracious gesture towards tourists, it was a clear signal that visitors were expected to carefully examine the individual works on display – many guidebooks, such as those describing Wilton, include entries about each painting and/or sculpture, directing readers to appreciate specific qualities. Outside the house, guidebooks were no less instructive: the guidebook to Hawkstone (Shropshire), for example, a house famous for its garden (and well-known for the comfort of its inn), provided information about the various views and spaces tourists would encounter as they toured the site and indicated what was to be admired at each stage.

As objects, guidebooks were designed to be functional, and book reviewers were very invested in how they were convenient for tourists. To that end, guidebooks are usually small, octavo volumes; and, while many of them are quite long, they are usually bound in paper covers, making them lightweight and inexpensive. Many, in fact, might reasonably be labelled pamphlets rather than books. Yet at the same time, guidebooks could function as mementos for tourists as well as practical aides.

This print shows Corsham House surrounded by trees.
Illustration of the frontispiece from John Britton, An Historical Account of Corsham House, London: Printed for the Author, 1806. (British Library, 796.e.19)



A guidebook’s appeal as a souvenir could be heightened by the addition of an illustrated frontispiece. The most common type of image was a view of the house itself, surrounded by the landscaped grounds, but it also depended on the particular attractions of the property. A number of the guides to Wilton, for example, illustrated one of the house’s sculptures on the frontispiece; that of Duncombe Park (North Yorkshire) displayed the ruins of Rievaulx Abbey, a site visible from the estate’s terraces.

Two people, a man and woman, are at the foreground of this print of Blenheim Palace. Just behind the figures is a lake with a small island filled with trees. At the background sits the palace.
Illustration from William Mavor, New Description of Blenheim, 8th edn, Oxford: J. Munday, 1810. (British Library, 10351.f.6)



The most elaborate guidebooks included series of illustrations. Some editions of the guide to Blenheim Palace (Oxfordshire), for example, incorporated a fold-out map of the gardens (often with hand-coloured details) and a set of views of the house, one each from the north, south, east and west.

Considered as a group, these guidebooks, many of which were available in London bookstores as well as near the houses themselves, might be said to be appealing to readers as texts which might be read for their own sake, after the visit to the house was over. In doing so, they were in effect claiming a greater relevance for their content, and for the cultural significance of information about country houses, their art collections and their gardens.

Jocelyn Anderson

Jocelyn Anderson holds a PhD from The Courtauld Institute of Art, where she wrote a dissertation entitled 'Remaking the Country House: Country-House Guidebooks in the Late Eighteenth and Early Nineteenth Centuries'. She recently completed a postdoctoral fellowship at The Paul Mellon Centre for Studies in British Art.

You can see more images from the country-house guidebooks discussed here on the British Library's Flickr page: https://www.flickr.com/photos/britishlibrary/

29 July 2014

Collection Care Top Ten

The Collection Care blog is a year old this week! It has been a wonderful 12 months for the blog, due largely to you, our loyal readers. Since fluid, food and flames are generally considered our nemeses, we'll hold off on the champagne and birthday cake. Instead, to celebrate, we have compiled a list of the top ten most popular posts. Boy, do we know how to party!

10. A-a-a-choo! Collection Care's Dust Busters: In this post we shared the work of our dust busting team who monitor dust in order to protect our collections. We took a look at what exactly dust is, and how to balance the benefits and risk of dust minimisation programs. Who you gonna call? Collection Care! 

The tops of two rows of various-coloured books are shown with ample dust visible on top of the textblocks.

 

9. Goldfinisher: He's the man, the man with the Midas Touch: Doug Mitchell is our book conservator and gold finisher extraordinaire. Doug demonstrated the blind tooling technique and showed us the variety of tools involved in the process.

A conservator picks up a piece of gold foil. Next to him is a book in a wooden press, with the spine facing upwards.

8. Sea Snails & Purple Parchment: Did you know that the colour purple found in many of our manuscripts comes from sea snails? The snails are essentially "milked" to extract a gland secretion in a very labour intensive process. 

A variety of small snails in shades of brown, tan, and white on top of a rock.

7. A Guide to BL book stamps: You've seen them on our collections and online, but what do they mean? Library stamps are generally divided into four types according to when they were in use, ranging from 1753 to the present day.

Two British Museum stamps: one in blue and one in red. The stamp features a circular crest in the middle with a crown on top. On the left side of the crest is a lion and on the right side is a unicorn. Below the crest and animals is a banner and above is text which reads BRITISH MUSEUM.

6. Digitisation as a preservation tool; some considerations: This post by Qatar Project conservator Flavio Marzo confronted the growing public expectation for online access. Marzo challenged the conservation community to use mass digitisation as an opportunity for the long term preservation of historical items and their features.

A screenshot of Microsoft Sharepoint. This shows various items arranged by shelfmark, and what stage in the conservation workflow each item is at.

5. The Bookie Monster: attack of the creepy crawlies!: Here we delved into the underworld of pesky pests who seek to eat their way through our collections. We identified some of the primary culprits and showed examples of damage to look out for.

A closeup of pest damage on paper. Small holes and tunnels are visible.

4. Cleaning and rehanging the Kitaj tapestry: What happens when creepy crawlies do successfully attack? This year we had to don our hard hats to remove the enormous R.B. Kitaj Tapestry If not, not from the St Pancras Entrance Hall for conservation cleaning. The tapestry was hoovered and frozen to remove all pests and surface dust before rehanging in the hall. It was a major operation and a complete success. We even made a time-lapse video!

Three people in hard hats stand on scaffolding and re-hang the large tapestry.

3. Fail to prepare for digitisation, prepare to fail at digitising!: Digitisation is much more than just taking a picture. With mass digitisation projects being announced every month, we shared what we've learned when it comes to preparation. We listed five main outcomes of pre-digitisation checks, which highlighted the potential risks in each case.

Four images showing books opened at various angles: the top two images are books open at gentle angles on black foam book wedges, the bottom left is a paperback book opened without any supports and the bottom right shows a hardback book being opened with no supports.

2. Books depicted in art: Being surrounded by books everyday is all part of the day job for us here in Collection Care. As you can imagine, seeing books in paintings can be quite thrilling. In this lavishly illustrated post we saw that some historical paintings contain a wealth of information about bindings that were not well-documented in the trade.

On the left is a painting of a man in black with white collars and cuffs in front of a book shelf. He is also holding a book in his hand. On the right is a closeup of some of the books on the bookshelf.

1. Under the Microscope with the Lindisfarne Gospels: Finally, in our most popular post, we shared microscopy images of the Lindisfarne Gospels collected by our team during a condition assessment. At up to 200 times magnification the medieval artistry and attention to detail blew us all away.

A magnified image of ink. Some brown dots sit high on the surface of the parchment. A brown ink shows the lettering with a teal ink resting inside letters (think filling in an o).

Many thanks to all our readers from the Collection Care team. As ever, we are truly grateful for your following and are always keen to hear from you. Do let us know if there are any topics you'd like to read about, and don't forget you can subscribe to the blog at the top of this page, and follow us on Twitter: @BL_CollCare


Christina Duffy (@DuffyChristina)

27 July 2014

Fleas, mould and plant cells: under a 17th century microscope with Robert Hooke

This week we celebrate the 379th birthday of Robert Hooke, a Fellow of the Royal Society and key figure of early modern natural history and natural philosophy, born on 28 July 1635. Many of Hooke's innovations paved the way for a more rigorous scientific analysis of materials, for which we in Collection Care are very grateful. To mark the occasion we are thrilled to host a guest post from Puck Fletcher who has just completed a doctorate on space, spatiality, and epistemology in Hooke, Boyle, Newton, and Milton at the University of Sussex:

Hooke’s most famous work is the Micrographia: or Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries thereupon, published in 1665 by the Royal Society. It is a descriptive work detailing sixty observations of specimens at magnification, starting with the point of a needle, ranging through silk, glass drops, hair, and various plants, seeds, and tiny insects, all viewed through a microscope. It closes with observations of the fixed stars and the moon as seen through a telescope. 

The top cross section is a circle. The  negative space is black, and there are two 'patches' of texture: cross section B on the left and A on the right. A is amorphous in shape, and somewhat giraffe-like in texture--it is made up of various dots which are not perfect circles. B shows a more rectangular texture and comes to somewhat of a point at the bottom. Below this is a branch.
Two cross sections of cork and a ‘sensible’ plant. In his description of cork, Hooke coined the term ‘cell’ for biological contexts. Image source.

CC zero 

The project was a collaborative one started by Christopher Wren who, in 1661, so impressed Charles II with his drawings of magnified fleas and lice (possibly the ones on which the corresponding Micrographia engravings were based), that the King requested more. Wren persuaded Hooke to undertake the bulk of this work and over the next few years, Hooke amassed his collection of observations, regularly bringing new drawings to the meetings of the Royal Society for approval by the other members.  

An illustration of a flea in profile. The fleas face is to the right.
Among the drawings and observations in Micrographia is this famous and extraordinarily detailed large-scale illustration of a flea. BL Shelfmark: 435.e.19, XXXIV. Image copyright The British Library Board. Read more.

CC by 

The impressive folio volume contains thirty-eight highly detailed engravings, which turned the book into an instant bestseller and secured its reputation as the most beautiful and lavish work of early European microscopy. The sense of magnified scale is staggering. A head or body louse, for example, is just a few millimetres long, but the engraved image is 52 cm long, roughly two hundred times actual size, a level of exaggeration that is emphasized by the fact that, large as the volume is, the reader must still unfold the oversized plate to view it.

Head or body louse from below.
Engraved image of a head or body louse, roughly two hundred times actual size.

CC zero  Image source.

For his readers, Hooke’s illustrations brought a whole new world into view. Hooke captures this excitement in his preface, describing how, by means of instruments like the microscope, ‘the Earth it self, which lyes so neer us, under our feet, shews quite a new thing to us, and in every little particle of its matter; we now behold almost as great a variety of Creatures, as we were able before to reckon up in the whole Universe it self.’ Pepys was famously so enamoured of the book that the day after he brought home his copy, he stayed up until two in the morning reading it, describing Micrographia in his diary as, ‘the most ingenious book that I ever read in my life’. 

When looking at the large-scale, clear engravings in Micrographia, it is easy to imagine that this was the view Hooke had in his lens and that his task was simply that of looking and then recording what he saw. However, the practice was much more difficult and required considerable skill and experience – when Pepys looked through his microscope, he was disappointed to find that at first he couldn’t see anything at all! The lens making technology of the time meant that impediments to clear vision such as chromatic aberration or artefacts in the glass were not uncommon, and the view through a microscope was often blurred, distorted, and dark. It was difficult to make out true colours or to tell whether a shadow was a depression or protuberance, and the field of vision was quite small.1

Part of Hooke’s contribution in Micrographia was his skill as an instrument maker and technician. Although, as he reports, he had difficulties in seeing through his microscope, Hooke made his own adaptations to the commercially manufactured instrument, in particular devising an improved light source, which he called his ‘scotoscope’.  

A drawing of the 'Scotoscope'. The eyepiece one would look down is similar to what we use today, if a bit more 'pretty' with floral engravings. To the left of that is a flame providing light.
The microscope, featuring an improved light source.

CC zero  Image source.

Hooke also worked diligently and looked very carefully, making multiple observations from multiple angles, of multiple specimens, created with various preparation techniques, to gather enough visual information to be able to produce a single image of what the whole object looked like, as near as he could make out. For Hooke, the act of looking through the microscope and recording what he saw was an interpretive one.

Hooke’s observations have been praised by modern scientists for their accuracy, and Howard Gest even credits him with the first accurate description and depiction of a microorganism, the microfungus Mucor, described by Hooke as ‘blue mould’.2 

In this illustration, blue mould looks flower like, with stems coming from the surface, some of which end in circular balls and others which end in petal-like shapes.
The microfungus Mucor (‘blue mould’).

CC zero  Image source.

In his preface to Micrographia, Hooke heralds ‘artificial Instruments’ such as the microscope and telescope, and the methods of the new science based on observation and the careful and rational scrutiny of results, as at least partial correctives for the failings of fallen man and his limited sensory faculties. He also looks forward to the technology of the future, which he believes will enable man to see even more clearly.

‘’Tis not unlikely, but that there may be yet invented several other helps for the eye, at much exceeding those already found, as those do the bare eye, such as by which we may perhaps be able to discover living Creatures in the Moon, or other Planets, the figures of the compounding Particles of matter, and the particular Schematisms and Textures of Bodies.

Puck Fletcher

1Brian Ford’s wonderful book, Images of Science: A History of Scientific Illustration (The British Library, 1992), pp. 182–83, contains a photograph of the partial and distorted view through the sort of lens used by Hooke.  

2Gest, Howard, ‘The Remarkable Vision of Robert Hooke (1635–1703): First Observer of the Microbial World, Perspectives in Biology and Medicine, 48.2 (2005), 266–72 (p. 267).

19 July 2014

Secret underdrawings & cover-ups in the Mewar Ramayana

The Ramayana – “Rama’s journey” – is one of India’s oldest stories having first being written some two and a half thousand years ago. It follows the hero Rama from his birth and childhood in Ayodhya to his exile in the forest where his wife Sita is kidnapped by the wicked (and ten-headed!) demon king Ravana. With his valorous brother Lakshmana and helped by an army of monkeys and bears he leads the search for Sita, finally rescuing her from Ravana’s stronghold in Lanka. It is an epic story embodying the Hindu idea of dharma (duty). There are several thousand known surviving manuscripts and many different versions of the story across Asia. The Mewar Ramayana is one of the finest copies of the work, lavishly illustrated with over 450 paintings in large format. Recent digitisation by the British Library in partnership with leading Indian institutions has reunited the long-separated text and it can be viewed online featuring an introduction including links to contextual documents and high resolution images in ‘Turning the Pages’ with descriptive text and audio.

Multispectral imaging

We recently examined two paintings from the Mewar Ramayana using multispectral imaging to investigate the methods and workflow of the artist. Images are captured over fourteen spectral bands from the ultraviolet (UV: 365 nm) to the infrared (IR: 1050 nm) revealing information about underdrawings and techniques that can’t be seen under normal light. The two full page paintings are illustrations from Book 6 (Yuddhakanda, Book of war) of the Mewar Ramayana manuscript.

Book 6 fol. 27r (Add. MS 15297(1), f.27r)


Book 6 fol. 27r depicting the siege of Lanka in colour, ultraviolet, infrared, and blue light with an orange filter. Rama’s army of monkeys takes control of the four gates of the city as the ten-headed Ravana leads the defence after consulting his ministers.

Book 6 fol. 27r: Rama’s army of monkeys and bears hurl stones at their enemies. White pigment, possibly added as a later touch up, is observed under ultraviolet light on the elbows, arms and tails of the attacking monkeys.

Book 6 fol. 27r: Colour, ultraviolet, infrared sequence. In front of the gates to Lanka, a man struggles with a monkey. Under ultraviolet light the rough application of paint is evident on the man's hand where no attempt is made to stay within the lines. In the infrared image, the guidelines used to initially draw the figure (chest, back, elbow) are observed.

Book 6 fol. 27r: An archer fends off the monkey army. Incorporating high levels of detail in these paintings often led to a change in design layout. In the painting the archer is shown to be sitting cross-legged on the cart, but in the infrared image he is standing. The late addition of the cart is evident by the over painting of the wheel in order to indicate its attachment to the main frame of the cart. Other alterations were made such as the size of the soldier's orange foot in the top left, and the painting over of an isolated monkey tail on the horse's body in the bottom left.

Book 6 fol. 142r (Add. MS 15297(1), f.142r)

As the battle escalates Rama’s brother Lakshmana is seriously wounded by a spear. Hanuman the monkeys’ army general is sent to the Himalayas to pick up medicinal herbs.

Book 6 fol. 142r: Colour, ultraviolet, infrared, and blue light with an orange filter sequence of the painting.

Book 6 fol. 142r: Colour, ultraviolet, infrared sequence. Rama’s loyal brother Lakshmana is seriously wounded by a spear. In the ultraviolet image we can see touch-ups on the hands, arms and legs of the two monkeys trying to take the spear off Lakshmana. Under infrared light we can see underdrawings of the far left monkey who was originally positioned higher up.

Book 6 fol. 142r: Colour, ultraviolet, infrared sequence. In the ultraviolet image alterations to Rama’s clothing and the direction of arrows is observed. Under infrared light, the boat at the top of the painting with the three figures is shown to have been altered. It may have started out as a representation of deities in the sky similar to those seen in Mughal Mahabharata (Razmnamah) Or. 12076 f.76r. Other arrow positions have also changed.

Book 6 fol. 142r: In the infrared image, a different position for the ten-headed Ravana is shown to the right, where a single face in profile is revealed adjacent to a vertical line. This is completely obscured by the green pigment which we now see.

Multispectral imaging has proven a wonderful technology in allowing us to study collection items in new and exciting ways. These are just some of the observations made and we hope to share more in the future.

Christina Duffy (Imaging Scientist) and Pasquale Manzo (Curator Sanskrit)

16 July 2014

Selfie as methodology: researching sedilia in English parish churches

The valedictory symposium of this year’s Material Witness was recently held at the Art Workers' Guild, London. Material Witness is a programme for post-graduate Humanities researchers investigating the place of objects and first-hand experience in scholarship in today’s digital world. One of the papers by James Alexander Cameron, who is completing a PhD at the Courtauld Institute on sedilia in English churches, particularly brought out the importance of embracing both digital and physical study of objects, as we do at the British Library.

A series of three sedilia next to one another in a church, with the author sitting in each one. The seat on the left is the lowest, with seats gradually rising in height toward the right.

CC by Left: Cherry Hinton (Cambridgeshire)

Sedilia are the seats by the altar for the use of the priest, deacon and subdeacon celebrating Mass. In English churches they often take the form of three stone niches, built into the wall of the chancel. My research has shown they seem to be largely, but not exclusively an English phenomenon, becoming common in the thirteenth century and reaching their height of popularity in the early fourteenth century.

I have amassed a database of all the sedilia in England using the Pevsner Architectural Guides, supplemented by hyperlinked images gathered mainly from the website Flickr. There are over 1,300 items in my database, 800 being what I dub the so-called “classic” sedilia: the set of niches set in the thickness of the wall, surmounted by arches and divided by columns or shafts.

So in many ways my thesis is made possible by the new phenomenon of mass public-domain photo sharing, such as the British Library has recently begun. I also try to share my rather pedantic pictures of churches and their furnishings on Flickr as much as my time allows in the hope someone else might find something in them as useful as I found the pictures of sedilia.

Four versions of the author sit in sedilia in Westminster Abbey. These sedilia have four arches at a sharp peak and are made of a dark wood.

CC by Right: Westminster Abbey

But I am quite eager to use not just my hands, but my whole body in my research. Very few sedilia have as luscious sculpture as those of the 1320s in Heckington church (Lincolnshire), microarchitectural canopies as fantastic as Exeter Cathedral or painting as top-whack as Westminster Abbey. The vast majority are just niches in the wall, more common proportionally in ordinary parish churches than cathedrals. There are rarely ever any signs of use in the form of traces of fittings such as hanging fabrics or cushions. It seems that quite simply, clergy sat in them during the points of the service when they weren’t doing anything else.

The author's photography set up showing a camera with tripod in the foreground and one singular version of the author sitting in the middle seat of a sedilia with the seat on either side of him empty.

CC by Left: Morton (Lincolnshire)

So that’s what I do: I sit in them, with a tripod on a timer for three exposures 2 seconds apart. And then I make a montage of the resulting pictures when I get home. I have around 130 of these montages, which means I have sat in around 10% of all the sedilia in England (possibly sounds slightly more impressive than it is).

 

CC by Right: Castle Hedingham (Essex)  The author in the sedilia in Castle Hedingham. This sedilia is stark white with curved arches with a geometric pattern following the curves.

This isn’t just a completist mania, as from the first time I did it (to be quite honest initially as the one-off gag everyone thinks it is) at Castle Hedingham in Essex back in 2011, I realised what an extraordinarily useful way it was of recording the scale of sedilia. Because even though they generally look very similar, sedilia come in such varied shapes and decorative forms, to gather their dimensions in any meaningful way with a tape measure would be nigh-on impossible. And to see at a glance the claustrophobic niches at Castle Hedingham, made me realise that although the current carving is 1873, you can see the traces of the original twelfth-century arches that they were placed inside of, resulting in their uniquely cramped proportions. Since then, unless the sedilia are stuck behind an immovable object, I’ve done this shot.

Three versions of the author stand in a stone archway at Kirkstall Abbey

CC by Left: Kirkstall Abbey (West Yorkshire)

Seeing the scale at a glance is important, particularly for some of the earliest sedilia that do not have the demarcated niches, such as the Cistercian Abbey of Kirkstall near Leeds, probably built in the late 1150s. The austere Cistercians were a bit weird among the other great monastic abbeys at this time for just having chancels with blank walls around the altar: most orders would have aisles all the way round: the arches of which would be useful to put a bench between for the ministers of the high altar. When you actually visit Kirkstall, you see that the sedilia niche, one of the earliest in England, is much higher than it needs to be, and that the builders are actually creating a false bay of an arcade for the clergy to sit under, rather than the more identifiable genre of “classic” sedilia that came along later.

Three versions of the author in the sedilia at Heckington. These are made of a light-coloured stone, with decorative elements forming sharp peaks above.

CC by Right: Heckington (Lincolnshire)

And then those sedilia at Heckington, often pictured in books on parish churches for their wonderful sculpture of everyday life and extraordinarily well-preserved Coronation of the Virgin, but if you sit in them you can demonstrate how high up this sculpture is, and how the men in the seats were not the primary audience of it. Instead, the Coronation of the Virgin represents Christ’s charge to Mary as Ecclesia, the representation of the Church, and interacts with the bodies below as a visual ensemble of the Church Militant on Earth and the Church Triumphant in Heaven.

See more about my project at my page on the Courtauld website, and how you can help by sending in my missing sedilia.

James Alexander Cameron

The Courtauld Institute of Art

09 June 2014

Know Your Yellow!

This rather ancient looking Qur’an is deceptively young. In fact, it is thought to date back to the early 18th to late 19th century. The style is typical of African manuscripts originating south of the Sahara, and was presented to Lt. Heygate of the British Army, in Nigeria in 1916.

A book in a rectangular dark brown leather wrapping lies on a grey background. The picture is sideways, so that the head edge of the book is on the right-hand side. The wrapping is decorated with concentric rectangles of dots and lines imprinted onto the leather. A triangular leather flap folds over the front of the book from the spine edge, which is at the top of the photo. A leather thong is threaded through the point of the triangle. The leather is faded and is splitting at the spine edge.
Front
The unbound textblock lies in the middle of the open wrapper, with a dark brown leather board on top of it. The leather of the underside of the wrapper is much paler leather of a light orange-pink colour. There is an old repair on the right-hand side of the wrapper, where a tear has been repaired with white thread.
Front Open

CC by Above: Manuscript in its wrapper. Below: Manuscript sandwiched between its boards with the wrapper open

It has a number of components; starting from the inside, there is an unbound textblock with thick tanned, haired goatskin boards on top and bottom. This in encased in a goatskin wrapper, which then fits into a goatskin satchel. This multi-faceted construction is similar to other 19th-century Qur’ans from West Africa, south of the Sahara.

A rectangular satchel with a triangular flap lies on a background of dark grey foam. The main body of the satchel is made from an orange-brown leather, and is decorated with square and diamond-shaped motifs of red-brown leather. The edge of the flap has a dark brown leather trim and the top edge of the satchel has a wide strip of the same, decorated with vertical and horizontal lines. The strap of the satchel is made from plaited strips of leather.
Satchel

CC by Satchel lying on inert grey foam, with acid-free tissue padding to retain shape

The manuscript lies open to its first page, on a grey background. The pages are a creamy-brown colour and have rounded corners, with creases and small tears to the page edges. A piece of paler paper with black handwriting on it lies on top of the first page. To the right of the textblock is the top board, with its underside facing upwards. This is still covered with animal hair, which has a black and white spotted pattern.
First page

CC by Left: Manuscript open at first page with the letter detailing its origin inserted

As exciting as it is to have this fascinating object in the studio, it is responsible for some real headaches as a result of one particular element of its composition. Before an object comes to the studio to be worked on, a conservator will often carry out an assessment of its condition and write a treatment proposal, estimating the time and materials likely to be used. In this case, when my colleagues carried out the assessment, a large proportion of the textblock was ‘blocking’. This simply means pages were sticking together, which meant that most of the book was unreadable.

Strangely, in the period of time between the book arriving in the studio and the point where I took it out of the safe to work on, around a third of the textblock had released itself. This is not something conservators are trained to expect; most things get worse over time, so to see something improve without our intervention was exciting!

The only conclusion we can come to is that the studio’s environment is slightly different to the one the manuscript came from. The difference in the moisture levels in the air is the most likely culprit. 

A page of the manuscript showing Arabic writing in red and black ink. The picture is sideways, so that the text flows from the bottom to top of the photo. There are yellow dots placed throughout the areas of text.
Pigment detail

CC by Detail of yellow pigment, orpiment

On closer inspection the ‘sticky element’ was discovered to be yellow dots painted intermittently within the text areas. These were tested by our Conservation Science team, and found to be orpiment (a poisonous, arsenic-based yellow pigment) mixed in a medium of gelatine. It is the gelatine that is fairly hydrophilic, which would have softened in a humid environment and stuck to anything in direct contact with it.

So the obvious solution to this is to change the humidity levels around the volume further, to release all of the sticky dots. If only it were simple! The brown ink you can see in the image is most likely iron gall ink, which has been used as a writing medium since ancient times. Its main characteristic is that once it’s a few years old it turns from purplish-black to brown. Another, less innocuous ageing property, is its potential to ‘burn’ through the paper it sits on. The extent of the damage can depend on the recipe the scribe followed to make the ink; some are more acidic than others. But it can also depend on the level of humidity the ink has encountered in its lifespan. The introduction of medium to high levels of moisture, even in vapour form, can solubilise ions contained in the ink, which can catalyse the oxidative degradation of the cellulose fibres of the paper. This leads to weakened paper and potentially a severely damaged collection item.

A page from the manuscript, featuring an illustration. The picture is sideways, so that the head edge of the book is on the right-hand side. The illustration lies across the centre of the page and consists of a rectangle divided into three panels. The two outermost panels are subdivided into smaller squares and triangles, coloured in white, yellow and red. The central panel has a pattern of red and yellow stripes interwoven with each other. There is also a small circular motif in black, yellow and red in the left margin. The text above the main illustration is in black and red ink.
Text

CC by Detail of one of the illustrations amongst the text

So keeping it dry is the best option for the ink, but pulling apart the pages without moisture could lead to skinning off the top layer of fibres, or even tearing paper.

We’re still deciding what to do about this sticky dilemma, but as ever with conservation decisions, we will have to balance our need to enable access by our readers to collection items with the wellbeing of individual items. Never a dull moment!

Jo Blackburn

03 June 2014

Materials Testing: The Oddy Test

When items from the Library’s collection (and from other institutions) are exhibited to the public, it is important to ensure that none of the other materials used as part of the display (fabrics, foams, plastics etc.) will cause problems, for example by becoming acidic or releasing reactive gases as they age. As a result we work closely with the British Library’s Exhibitions Department to test the stability and compatibility of any new materials that are under consideration for use.

The ‘Oddy Test’ is an accelerated corrosion test developed by conservation scientist Andrew Oddy at the British Museum in 1973. It is used to predict potential off-gassing from new materials to determine whether they are safe to use with collection items in an enclosed space. The suitability and compatibility of a material coming into close contact with a collection item is predicted by measuring (semi-quantitatively) the extent to which a new material will release harmful volatiles over a long period. If enclosed in a small space, volatile components such as organic acids, solvents, oxidants and sulphur compounds may reach dangerous levels of concentration capable of damaging objects through corrosion of metals or degradation of organic matter.

Eleven rectangular swatches of fabric in a variety of bright fabrics lie on a wooden tabletop.
Fabrics Testing

CC by Fabrics for testing

Enclosed spaces could include showcases for exhibition, storage crates, contained shelving or individual item storage boxes. It is important to test all of the materials that the collection item will be exposed to in order to ensure the item is not at risk of damage. For example in the case of a new storage box for loan transport we would test a small sample (approximately 1g) of the board, fabric, adhesives and foam which make up the box.

Method

The original Oddy Test has since been developed into the 'three-in-one' method, but the theory is the same. In the original setup samples of the material in question are placed into three separate test tubes. Approximately 1 ml of de-ionised water is placed in a vial inside each of the test tubes to maintain a high relative humidity. In the first test tube a clean metal token of copper (Cu) is suspended over the sample on polyester thread, in the second a token of silver (Ag), and in the third a token of lead (Pb).

A hand-drawn diagram of a cross-section of a sealed container. On a frame within the beaker, a roughly circular sample of black material to be tested sits on a platform above distilled water, which is coloured in blue. Above the sample three rectangular metal samples coloured orange (copper), blue (silver) and lead (grey) are suspended from a frame.
The Oddy Test



CC by Schematic of the 'three-in-one' Oddy Test. Image source

The test is evaluating the extent to which a new material corrodes these metals, and any alloys containing them. Copper, silver and lead are used because they react to a different set of gaseous pollutants, but results are applicable to all material types. Copper detects chloride, oxide and sulphur compounds, silver detects reduced sulphur compounds and carbonyl sulphides and lead detects organic acids, aldehyde, and acidic gases. Three identical test tubes with metal tokens and de-ionised water are setup as a control.

The containers are sealed up with glass stoppers and secured in place with heat-shrink tubing. To mimic the aging conditions they are placed into a heated oven held at 60 °C. This replicates a ‘natural’ ageing process of approximately 5-6 years. When 28 days have passed the containers are removed from the oven and the tokens are examined. The presence of volatiles is indicated by any corrosion or tarnishing of the tokens. The extent of corrosion gives a rough indication of the level of off-gassing. If the tokens show no signs of corrosion then the material is deemed suitable for use with collection items. 

The inside of an oven, in which there are three shelves. On each shelf there are between eight and eleven glass jars with white lids. The jars contain small pieces of grey and orange metal and are marked on their lids with black pen.
Oddy tests in the oven

CC by Sealed jars containing Oddy Tests in an aging oven. Image source

Further Oddy Test developments have seen the 'three-in-one' test where all three metal tokens are placed in the same container over the sample, making sure they are not touching each other or the sample. The interpretation of the results is somewhat subjective given that visual cues such as changes in lustre, colour or texture are used to classify the suitability of the test material for use.

Stability of the materials can be further tested with the use of Image Permanence Institute ‘A/D’ strips. These strips measure the short-term release of volatile organic acids. Oddy testing is just one of several tests that a material must pass before it is accepted for use near a collection item. For example infrared spectroscopy allows us to determine the chemical composition of the sample, enabling us to predict its likely behaviour. Surface pH measurements give an indication of the way in which the acidity of the bulk sample changes over time.

By working with conservators and the Exhibitions Department in this way, we help to ensure that the Library’s collection can not only be displayed in the best possible manner, but that it is also preserved for future generations.

Christina Duffy (@DuffyChristina) and Paul Garside

 

Further reading

The British Museum published the results of material test results (Oddy and pH) carried out on materials at the BM from 1996-2004

Bamberger et al., Studies in Conservation, Vol. 44, No. 2 (1999), pp. 86-90

Robinett and Thickett, Studies in Conservation, Vol. 48, No. 4 (2003), pp. 263-268

Collection Care blog recent posts

Archives

Tags

Other British Library blogs