Seeing the Google doodle today I see that x-rays are 115 years old today. Happy birthday x-rays!
Google doodle celebrating 115 years of x-rays
X-rays can be really useful for conservators working with most any type of material, but particularly archaeological finds, and they have been used extensively during the work in the CSI: lab. You can read more about the use of x-rays in an earlier post. This post, however, is a gallery of just some of the x-rays that have been taken for objects in the lab – most are swords.
Sword from grave 158 with copper alloy ring and knife fragment
X-ray of block-lift containing a sword and knife
X-ray of block-lifted sword containing an interestingly detailed silver buckle and pattern welded blade
Middle of a sword from grave 182
Tip of the sword from grave 182
X-ray image of Anglo-Saxon brooches and buckle
Archaeologists are baffled by this x-ray
OK, the last one isn’t one of ours, but it’s pretty cool.
If you want to find out more about x-rays have a look at the links below.
English Heritage Guidelines on the X-radiography of archaeological metalwork
Also, kind of related to x-rays and bones (…well bones at least), is Paul Evans’ blog ‘Osteography‘. I noticed this advertised in the corridor at university and it appears to be quite interesting, so well worth having a look at. Have a look also at his earlier project, ‘Origin 09‘.
click to enlarge
Knife before treatment
This iron knife from grave 168 has been cleaned by volunteer Shirley. The grave was that of a male and other finds included a shield boss with fittings and a second knife.
Although quite a small find, the object has presented several areas of interest for the volunteers, conservators and archaeologists.
As mentioned in other posts on this blog, there was very little bone found due to the high acidity of the soil. In some cases volunteers have managed to find evidence of bone attached to some objects and this find is one such case where this has occurred.
The thumbprint in the knife discovered during conservation
Extensive areas of bug pupae cases were also found during the investigative conservation process of this object. If identified, this evidence may help determine what time of the year the person died and the grave was made.
Yellow-coloured patches uncovered in the soil suggests the presence of leather, perhaps a sheath or handle for the knife or maybe even an item of clothing that was in close contact with the object.
However, perhaps the most exciting evidence found on this object is the possible fingerprints of the man preserved in the corrosion products. The presence of such evidence suggests that the knife was being held by the person within the burial.
For anyone not familiar with conservation and the importance of carrying out such work on objects like this only need to take a look at an object such as this. What might seem a fairly standard and pretty uninteresting object on the face of things has proved to be an extremely valuable and interesting object that has given us a great deal of interesting information.
This type of object is also a small find that might otherwise not have been worked on. As the volunteers and conservators involved in CSI: Sittingbourne are working on nearly all the finds from the graves there is a greater ability to understand and work on these finds to find out even more information than would be possible in other circumstances. This is an excellent aspect of this project
This isn’t really new news as the image was posted up a couple of months ago, but I completely missed it!
Following a topic about the CSI: “mystery object” on Ða Engliscan Gesiðas (The English Companions) discussion group forum, “the society for people interested in all aspects of Anglo-Saxon language and culture”, this image was posted by Æscwine (aka John Wills).
Suggestion to the likelihood of the "mystery object"
Here is John’s theory and what he had to say;
“Looking at all the possibilities I think we can discount a brooch as a leather and wood backing on a brooch does seem right at all. Why would a piece of horse tack have wood on it? If it was a scabbard or sheath fitting then where is the weapon? If it is a “plain” shield decoration or repair where is the shield boss and the associated rivets?
It looks to me to be part of a belt pouch, I suggest that it was pouch similar to the Sutton Hoo purse, i.e. one with a “hard lid” with a soft bag behind. If this is the case then the lid was made of a thin sheet of wood covered in leather and this disk fitted to the front of the lid. The three holes had thongs woven through them which then came out through the centre hole to act as a fastener.
It’s a bit of a stab in the dark but if it was anything else then where is the rest of it? If leather and wood have survived then I find it improbable that a seax, sword, shield boss would corrode away leaving just this or that the guys putting this chap in the ground would put an empty sheath or half a shield in with their kin. This leaves it as an attachment to a reinforce leather object and down by the hand at the side of the body it just screams purse/pouch, the chap was hardly wearing a wooden belt or trousers!”
In my limited knowledge I think this is a very credible suggestion from John. Do you agree with his suggestion or do you reckon he’s talking rubbish? Why not leave your own suggestion or any other information that you think may help.
Also, if you would like to find out more about Ða Engliscan Gesiðas why not visit the website? There are regional groups and a quarterly periodical is published for members. Click here to discover more.
Filed under: Conservation
CSI: Sittingbourne was given a few valuable funded hours to carry out scanning electron microscopy (SEM) on a selection of interesting objects from the site. The availability of time for such analysis is valuable and CSI: Sittingbourne would like to give credit to Greenwich University science department for donating use of the SEM, as well as everyone who also helped out.
SEM image showing gilding and intricate tooling to one of the brooches
Despite the majority of volunteers not having any formal university training in conservation, they have shown themselves to be brilliant at discovering and identifying interesting things on there objects. In previous posts it has been mentioned that a great deal of mineral-preserved organics have been found and it was mainly these that were analysed further with the SEM.
The Scanning Electron Microscope, or SEM, is an incredible tool for observing complex microstructures of materials. Where conventional light microscopes use a series of lenses to bend light waves and create a magnified image, SEM uses electrons instead to create images. These images are able to show in much more detail the complexity and topography of a surface, which can aid in the identification of various materials. Click the images to see full size.
Complex wool structure shown using SEM
As well as looking at the surface, SEM can also be used to find out the composition of materials. Metals such as copper alloy, for example, can be examined to establish what metals have been used, which can also inform us of the technology utilised in the manufacturing. X-ray fluorescence (XRF) was employed for the same application with the spearhead.
The presence of bug pupae can help establish the time of year when the grave was made
The images show intricate handmade wires and gilding, but also include insect wing casings, wool, pupae and textile.
Intricate handmade wires
The images have not only helped with the interpretation of the site and the objects, but have also provided new display in the CSI: lab. The enlarged pictures were put on display at the celebration day held in March and are still on display for visitors to CSI: Sittingbourne to see.
Like the pupae, the presence of insects may help determine the season the person was buried and if the grave was left open
To find out more about SEM have a look at these links:
Saucer brooch partially cleaned for "press shots"
There were only a few brooches discovered at The Meads. The saucer brooch featured in an earlier post about conserved objects, and pictured above, has now been completed. The brooch was carefully mechanically cleaned using a scalpel to remove the bulk of the surface soil. The remainder was cleaned by swabbing with a paste of IMS and marble flour. The results are impressive and give us a much clearer idea of the design and manufacture of the object. Unfortunately, one of the garnets became detached but this is very common and can be easily rectified.
The completed brooch following conservation
Filed under: Conservation, Grave Objects | Tags: Conservation, spearhead, volunteers
There were around 29 spearheads uncovered during the excavation at The Meads: these are always found in male graves. Conservation has presented us with the usual mineral preserved organics on these objects. Wood is usually found preserved in the socketed ferrule where the spearhead attaches to the wooden shaft, and grass has been discovered on the surface of some suggesting the grave was lined or covered with grass before the person and objects were buried under soil (…although I doubt this was for their comfort).
Gold makers mark on the iron spearhead
This spearhead was discovered in grave 192 and is perhaps a bit more interesting than similar examples. What differs from the others from this site is the presence of a makers mark inlaid in the iron. This appeared to be a square with an arrow on the top, and could be clearly seen on the x-ray image so the volunteer working on this object knew that extra care needed to be taken. The spearhead was cleaned using a scalpel and air abrasion in order to reveal the mark. The mark looked to be gold: this was later confirmed when CSI: Sittingbourne were able to use a portable XRF (x-ray fluoresence) machine to positively identify the type of metal used.
Drawing of the makers mark present on this spearhead
Hopefully we can find similar examples of this on some of the other objects that are being worked on. If you want to see what’s going on the CSI: lab is still open for visitors to come and see what is being worked on. The exhibition opposite is open at the same time so you will be able to see some of the other objects and discuss the site with whoever is in charge.
Filed under: Conservation | Tags: gold, grave plan, niello, shield boss, silver, sword
There were two of these decorative fittings found in grave 174 at The Meads. Grave 174 is a male grave consisting of a number of objects including a shield boss, spearhead, sword and one object said to be Bronze Age. The grave also contained some human remains, one of the few where some survived.
Photo of the excavation of grave 174 (Image copyright Canterbury Archaeological Trust)
These decorative pyramidal decorations were found associated with the sword. They were located close to the mouth of the sword scabbard, and are perhaps part of some kind of strap due to the appearance from the back.
Plan of grave 174 - objects 7 and 8: click to enlarge (Image copyright Canterbury Archaeological Trust)
The objects measure just over 1cm square and are manufactured from silver. The peak is flat and is inset with a red garnet. Behind this is gold foil, something that would have made the stone sparkle a little more: we also see this on many of the brooches. Some other good examples of this can be seen on finds from Sutton Hoo and the recent Staffordshire Hoard.
Pyramid mount before conservation
The sloped sides of the pyramids have some decorative “cut-outs” that appear to be gold plated. Niello decoration is also present. Niello is a black metallic alloy consisting of silver, copper, sulfur and lead. It is used to inlay metals, and was utilised extensively throughout the Anglo-Saxon period. Perhaps the finest example of this is the great gold buckle which was discovered at Sutton Hoo. These were heated and fused much like with the production of enamels in jewellery and glassware.
The objects were mechanically cleaned using a scalpel and then swabbed using a paste of IMS and marble flour. The marble flour acts as a very fine abrasive in order to help remove the more stubborn soil. Whilst swabbing one of the pyramids some niello came loose. This gave us a chance to see the fineness of the detail present on these interesting little objects.
Pyramid mount after conservation
“It was nice to be able to work on such an interesting object. Iron can be very interesting and can preserve a lot of valuable information that can tell us a lot about the object and the people, but it is nice to be able to work on different materials and objects, especially jewellery. It is much easier to establish when to stop cleaning on objects like this and the results are really pleasing.”
Filed under: Conservation
CONSERVED OBJECTS
This page aims to show you what we have been working on in the lab. The page will be updated as and when we have worked on something interesting. Be sure to check back regularly.
VOLUNTEER OBJECTS
Volunteer Sylvia has written a short piece on a copper alloy object she has been working on.
“Thinking back over the past 3 months probably the best thing I have worked on was a copper ring – not much to get excited about there you might think but this ring was about an inch or more in diameter, it brought to mind the kind of ‘woggle’ Boy Scouts used to keep their scarves in place but this was shiny like malachite, the precious mineral, and much the same colour too. It was thick with Swale mud and the only way to clean it was with a cotton bud soaked in IMS. Through the microscope the surface was cracked and pitted, a small fragment broke away and revealed charcoal coloured copper beneath. At first I thought it was enamel but after working for a while on it I realised enamel would not be so thin a covering as this; apparently the original description of ‘copper ring’ was just right. I could not wait to get back to work the following week and finish off this small ‘gem’ of a piece, then the imagination starts to race – who used this, and what for? Was it an ornament or a piece of everyday equipment? Belonging to a man or a woman? We may never know, so back to work on the next piece….”
DO YOU KNOW WHAT THIS IS?
This is an uncommon and unidentified object is made from copper alloy. It is silver plated on one side and has evidence of leather and wood on the reverse. There are several holes in the object and the diameter is approximately 7cm.
Front of 'mystery' object showing silver plating
Reverse of 'mystery' object showing leather and wood evidence
It comes from grave 115, which is a male grave and one of the richer ones with a sword present. According to the grave plan it was found on the left hand side of the man, probably close to his hand although we can’t be sure as no bones have survived in the burial.
Grave 115 plan showing whereabouts of the "mystery object" (Image copyright Canterbury Archaeological Trust)
JEWELLERY
In a number of the graves the archaeologists found brooches. These have already been cleaned and conserved and are in a safe place away from the CSI: exhibition. These brooches are gold and copper alloy and have very intricate and skilled decoration present. Garnet stones have been inlaid for added decoration and colour. These stones are probably of eastern origin, showing the links that the Anglo-Saxon kingdom of Kent had around the world. One of the brooches, with Frankish style influences, has been attributed to being made in nearby Faversham.
Part cleaned saucer brooch with inlaid garnet stones
Plated disc brooch attributed to being made in Faversham
BUCKLES
Buckles are a common find in Anglo-Saxon burials and are commonly associated with male graves. Some are decorative copper alloy and gold and others may be iron with decorative studs/rivets. Archaeologists believe that the people were buried clothed opposed to the objects being added as tokens to the persons life. A decorative gold plated copper alloy buckle was discovered at The Meads and has already been conserved. The volunteers have been working on iron buckles and have found decorative copper alloy and silver studs, along with evidence of mineral preserved leather against the surface of the iron.
Copper alloy buckle discovered in one of the graves
Volunteer Wendy is currently working on a buckle with decorative copper alloy rivets and has produced an ‘interesting’ illustration of her discoveries.
Illustration of iron buckle currently being worked on in the lab
SWORDS
There were 11 swords discovered when excavating the site. Most of these have either been fully conserved or partially conserved and have revealed a lot of interesting and valuable information. Some of these have even been taken to Switzerland for accelerated neutron tomography analysis, which is a non-destructive form of research aiming to look at the evidence for pattern welding on the swords. We should be getting some results back soon!
Below are some blog reports that have been written by student conservators who worked on these objects over the summer.
Anglo Saxon Sword – TMS II EX08 Grave 83 (237)
Before conservation treatment
Measures : 64 x 14 cm
The sword and the dagger was block-lifted together with cling film and plaster bandages.
It was covered with soil and stones from the grave (Fig. 1). We have to record what we see on the surface as it was close to the decaying body.
Fig. 1: The sword (green arrow) and dagger (blue arrow) covered with the excavation soil
The digital x-ray image (fig. 2) show the sword and the dagger in a badly corrosion state: the sword is fragmented and the metal is mineralized.
Evidence of stripes are not so obvious on it, compared to other swords from the same excavation. However, large black areas are visible on the sword (handle, mid) and on the blade of the dagger. These could be the remains of mineralised organic materials or they might also be from corrosion products under the soil. A sort of spiral at the edge of the sword taken maybe in a stripe is visible on the x-rays similar to the sword frome grave 115 (397). Besides, we can also see crossing lines on this sword which must be an evidence of the pattern welding. A grey area on the x-rays located between the sword and the dagger might possibly be a physical connection between the two objects (maybe mineralised organic materials ?) . On top of that a metal (?) object is located near this area on the handle of the dagger.
Fig. 2: Digital x-ray image showing the corroded metal, one stripe on the sword (black lines) with metal objects (red circles).
During the treatment
The first stage consisted with removal of the excavation soil using a microscope (magnification x10) find the last surface of the sword. We used a scalpel, brush and air abrasion for the mechanical cleaning and IMS (industrial methylated spirits) with water (50/50) to soften the soil.
This sword is particularly interesting because of the remains of mineralised wood where the direction of the grain differs (see below) and it is the only grave with this association of sword and dagger together. It was decided that we should analyse further by using neutron tomography analysis, located in Switzerland. Before turning and cleaning the other surface near the plaster bandages, we used CDD (cyclododecan) wax (fig.17) to protect the fragile elements between the sword and the dagger; the fragmented surface of the wooden sheath and other parts were consolidated with Paraloid B72 (acrylic resin) with 30% of acetone.
Over the course of this treatment, some elements were discovered that may be of interest to the archaeologist; they are listed below in the table.
Further examination and analysis with a microscope is required to:
- determine the type of organic and metal materials used and the techniquess required
- help for a reconstruction of the location of the various items on the unit and their function, to understand better the relationship with them and the others elements in this grave
Filed under: Conservation
WHAT DOES A CONSERVATOR DO?
A conservator is a professional who works on the conservation of heritage objects. Their work involves determining the structural stability of objects, and addressing any problems of chemical and physical deterioration. A conservator may carry out treatments based on an evaluation of the aesthetic, historic, and scientific significance of the objects in their care.
One of the CSI: volunteer conservators at work
Conservation professionals use a mix of practical experience and science to decide the best way to treat an object. There is a commitment to high standards and performance to abide by with the work as the objects are often very important. The ethics involving suitable treatments and practices are utmost importantance.
Conservators are usually university trained for at least three years, and can pursue this further if they so wish. There are a number of universities in Britain that cater for people wishing to enter the profession.
There are many different areas involved in heritage conservation. These include paintings, paper, buildings, textiles, sculpture, furniture, ceramics, photographs, gilding and archaeological conservation; along with numerous others. The CSI: lab focuses on archaeological conservation and aims to ensure as much imformation as possible is gained from the objects that are being worked on.
WHAT CAN WE LEARN FROM THE CONSERVATION PROCESS?
The process of conservation can teach us a lot not only about the artefacts but the people too. We can learn what materials were used, the technology available, any decorative features, where the materials originated from and also evidence of organic materials.
Mineral Preserved Organics
This is organic materials that have been preserved by the iron corrosion products. It includes materials such as wood, textile, leather, grass, barley and even insect activity. Due to the significant number of iron objects that are being conserved in the CSI: lab we have been finding a large amount of organic materials present on the surface.
This is valuable information that would otherwise be lost. Although the iron objects are not the most beautiful, they can be the most interesting and provide us with a lot useful information. On all of the swords there has been evidence of wood that represents the preserved scabbard. At other sites in Kent, barley has been found preserved against objects. This was probably placed in the grave as an aromatic to stop the dead body smelling too much.
Clues to Technology and Styles
These clues can be discovered by examining x-rays or using other non-destructive methods. The cleaning process can also reveal valuable information about the technology and materials the Anglo-Saxons possessed. For example, some of the brooches from the site were probably made in Faversham, with the garnet stones being of Eastern origin.
We were lucky enough to have the opportunity to have non-destructive neutron tomography analysis carried out on swords. The main objective of this analysis was to discover whether the swords had been made by pattern welding the iron. As the iron was covered by the minerally preserved wooden scabbard we ould not see the metal. This was a brilliant opportunity to discover some extra information about the swords without having to take physical samples.
The swords were flown to Switzerland for this analysis. Each sword is placed vertically in the machine and images are taken down the length of the object – sort of like stronger x-rays. The process took approximately 6 hours per sword. There has been a lot of information to analyse and collate and we are still awaiting the results. Hopefully we can post some images of this in the near future.
Filed under: Conservation
X-RAYS
X-raying of cultural heritage objects is a valuable analytical resource. In the CSI: lab it is used to look at the condition of the iron objects that have been excavated from the graves. The images produced can show breaks and weaker areas, and provide the conservator with a guide when they are working on objects.
X-ray of sword tip and 'dagger' from grave from grave 83 - you can see breakages in the metal
They can also give clues to a number of things such as manufacturing techniques (pattern welding), different types of metals and organic remains, and decorative features of the objects. Again, this gives the conservator an idea of what to expect when cleaning objects rather than working on them blind.
X-ray image of sword with pattern welding and silver buckle from grave 28
X-ray image of Anglo-Saxon brooches and buckle
The CSI: lab is lucky enough to have been donated an airport x-ray machine. This is the first time one of these machines have been used to x-ray archaeological objects and should help the conservators and will give the public a chance to see it in action.
