Relight my fire

Ancient vessels have usually gone through a lot before making their way into a comfortable museum store. First they have to survive the dangerous business of production and come out of the kiln intact and as intended. If they pass muster, they then have to make it through being packed up and shipped off to market, near or far. Then there are the ministrations of their new owners to be borne, with all the risks of having chips come off here and there through rough handling. Sooner or later, every amphora knows some clumsy owner is going to end up knocking its handles off. And then into a pit with it, where its carcass suffers further indignities as rubbish is thrown in on top, or into a tomb where the ceiling might fall in and inflict yet more distress. Only to be in danger once more from the swing of the excavator’s pick.

How any of these vessels makes it way into the present is a small miracle. But the traces of these past lives have their own value, and archaeologists often use the condition of an object as a way of figuring out its history. Does it show signs of use-wear, or ancient repairs? Did someone have a go at modifying the form and turning it into something new? Has it been adversely affected by the deposits in which it lay for so many years, or did they help to preserve it?

Signs of surface burning provide one such clue for the wannabe Poirot, pointing to the vessel having contact with some source of fire. If the burning is on the exterior, this might mean it has been used for cooking or heating. Burning around a spout or nozzle may well point to the object being used as a lamp. All-over sooting might point to some more momentous event, such as the object being caught up in a major conflagration of the room in which it lay. The questions begin with the discoloration of the vessel; they can usually be resolved by considering its shape and archaeological context.

However in the case of some of the material in the Institute of Archaeology Collections, this sort of deductive reasoning might well lead you down the garden path. Because in the museum bubble, all is not always what it seems.

There are a number of vessels and fragments in the Collection that used to belong to the UCL’s former Museum of Classical Archaeology. This museum was disbanded in 1998, dismantled by default in a rather sad story in which College took away its gallery and with it, its independence. The collection was taken to the Institute of Archaeology for temporary storage, and without any clear signs of a decision being made, swallowed up whole. Its loss was our gain, of course, but one can’t help feeling sad at the end of an era.

Within this collection are a number of pieces that have been discoloured by fire. ‘Aha’, says the sharp-eyed reader: ‘I see the link. Cooking pot, industrial receptacle, proof of a great disaster, some past Pompeii or towering inferno?’  Well kind of, but not as you might think. This damage was no ancient disaster, but a modern one. The fact is that the Museum of Classical Archaeology used to be located in the main part of College, putting it right in the frame during the period of the London Blitz. College was bombed twice in the war: in September 1940, and again in April 1941. In one of these two events, the Museum suffered the effects of the resultant fire. I have yet to discover specific details of how much of their collection was affected, but several pieces were covered with a layer of carbon that penetrated from the surface through into the very pores of the fabric. The heat was so great that it affected even the materials previously used to restore the vessels, making any attempt to undo the damage a major challenge.

As they stood, these blitzed sherds were not terribly useful for teaching, as the surface discoloration completely obscured their characteristic decorative motifs. So in 1947 a small experiment was carried out on 5 of the pieces to see if the damage could be reversed. These were taken away and refired at differing temperatures until the carbon was burnt away and the original colour of the pottery restored. Based on the results of this first attempt, some additional refiring was carried out on three more of the Collection’s vessels in 1985 and 1993 – a Geometric lid (UCL 1009), an Attic Black Figure bowl (UCL 1040) and a Mycenaean stirrup jar (UCL 1005).

There were some ethical and practical issues to be overcome before embarking on these later rescue missions. Firstly, would the objects survive the refiring process? Would it even be possible to return these pieces to their former condition and appearance? And finally, how would a modern refiring affect the future research value of this material? A particular concern was that it would invalidate any attempts to apply thermoluminescence dating techniques to the objects. The conservators and curator had to weigh up whether regaining a teaching aid was more important in the long term than losing some potential research data. In the end it was decided that it was, and the treatment went ahead.

A considered approach that involved testing the material by slowly raising the temperature by increments proved successful; the sherds were then cooled slowly in the kiln to avoid cracking. The carbon was burnt off, and the warm red and orange colours of the underlying fabric brought back to life. For those of you with a technical turn of mind, you can find a full discussion of the issues and methods used in the 1987 article by Davison and Harrison, ‘Refiring Archaeological Ceramics’, in The Conservator 11.1, pages 34-37.

So the collection that I’ve inherited from my predecessors is perhaps less of a fire sale than it was before, but we still have plenty of blackened material to contend with. My biggest problem is determining which, if any, of the sooty sherds left in my care are that way due to the misfortunes of war. Without records, I can’t be absolutely sure that the damage is modern, rather than ancient, and the people who might have been able to enlighten me on the matter are sadly no longer with us. So I guess we’ll have to leave our kilns and our restorative ardour to cool, at least for now.