My name is Sebastian Foxley. I am a conservator working as part of the Objects Conservation team at the Wiltshire and Swindon History Centre.  I have recently been working on a Roman vessel called a trulleus. A trulleus is a bronze sauce pan and trullei were used by Roman soldiers for cooking. Other examples have been found in Britain in Roman military camps but they are unusual in areas such as Wiltshire where there is little evidence of Roman military activity.  

The high level of workmanship and the fact that parts of the object are coated in a layer of silver suggest that this was not just a cooking pot for a common legionary.  Similar artefacts have been interpreted as belonging to officers but the item may not have belonged to a soldier at all.

 
The trulleus

The object was found as part of a hoard consisting of three trullei and two wine strainers found at Kingston Deverill in Wiltshire. The hoard and the conservation of one of the wine strainers are described in one of the case studies in the conservation page of our website www.wshc.eu/about-wshc/conservation.html.
When the items where first excavated the resources to have all five vessels cleaned and conserved were not available. Although one item was conserved the others had to wait still covered in soil from the field they were found in until they could be treated.  

For a piece of metalwork which had been buried since the Roman period the trulleus is in remarkably good condition. The vessel is almost complete and areas of the original silver coating have survived underneath the rim and on the inside of the bowl of the object.  

Interestingly the object has been repaired during the Roman period. There is a hole in the trulleus opposite the handle and a patch of metal had been soldered over this hole in antiquity. The patch had become detached during burial but was found with the rest of the object during excavation. It can be clearly seen where it fitted on to the side of the vessel over the hole.

 
Cleaning the trulleus

The first stage of the conservation process was to clean the object. Most of the soil could be gently removed from the surface with a bamboo skewer or cleaned off with swabs of cotton wool dipped in solvent.   This revealed a surface which has an almost black patina in places but is just as smooth as it was when it had been buried.  There are numerous scratches on the surface of the metal but the patina formed after they were made showing that the scratches also dated to the Roman period and may be evidence of the way the object was used and repaired.

In some areas particularly on the inside of the object the surface is covered in corrosion. Some of the corrosion could be removed with a scalpel.  This is delicate work which has to be done under the microscope to avoid scratching the metal. It was impossible to remove all the corrosion without damaging the object and so a thin layer of corrosion has had to be left in places.  

Once the trulleus was clean the metal patch could be reattached. Reattaching the patch will make the object stronger. The patch itself is in a delicate condition and will be much less vulnerable to damage when it is attached to the object.

 
Reattaching the patch

Reattaching the patch will also show how the object had been repaired during the Roman period. This is something that could well be of interest to researchers in the future. 

From the scratches and remaining solder on the object the position of the patch can be seen. The patch however no longer lies flat against the surface of the trulleus and so the gap between the two parts has been filled in order for the patch to be securely held in place. The filler was made by mixing an adhesive with glass microballoons.  These are microscopic bubbles of glass and because they are filled with air they make a very light weight filling material. The patch was held in place with several small plastic clamps whilst the adhesive dried.

There are some cracks on the patch and the area around the hole and these have been reinforced by adhering small pieces of nylon gossamer fabric across the cracks on the inside of the vessel. This fabric is so fine that a single layer of it becomes transparent when it is coated in adhesive.

The filler material is pure white and will stand out against the rest of the object.  As this is distracting to look at the infill has been painted with acrylic paint to match as closely as possible the colour of the surrounding metal.

The final stage of the process was to coat the object with a lacquer to help prevent any future corrosion. The lacquer works partly by preventing air from touching the surface of the object but it also contains a chemical which will inhibit corrosion.

 
The trulleus after treatment

The trulleus will shortly be returning to Salisbury and South Wiltshire Museum for display in the future. It is the third item from the hoard to have been conserved but this is not enough to permanently preserve the objects.  Each of the treated items is stored in an air tight container when not on display.  Silica gel is stored in the container with the object; this absorbs the moisture from the air and so prevents the metal from corroding further. If you have enjoyed this article, the following entries may also be of interest:

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