The level of craftsmanship of the cauldrons’ makers is also becoming apparent. Amazingly, the copper alloy has been reduced to a thickness of less than a millimetre towards the upper part of the cauldron bowl – and as little as a tenth of a millimetre in places. Crafting such large, thin cauldrons from so few pieces of metal would have required considerable skill, and probably would have been done through “sinking” (hammering into a concave indentation) or “raising”(hammering and annealing over a solid object) to shape and thin a blank into the metal sheet to be used for the cauldron bowl. The individual cauldron pieces also appear to have been riveted together carefully, with a high level of finish and only subtle variations in size and spacing between rivets.
What is also interesting is that the cauldrons appear to have repaired repeatedly, possibly over the course of their life. Twelve patches have survived on the interior of one cauldron and at least six on another, riveted into place. These patches would have covered and held together tears or weaknesses in the thin copper alloy, whether caused through use of the cauldron, or even during the delicate construction process itself.
Amazingly, through micro-excavation our conservators have even been able to identify what they believe is the handiwork of several different craftsmen - with differing levels of skill – working in phases of repair, perhaps during manufacture and over a number of years of use, by identifying differences in the shapes of rivets, regularity of patches, and the way rivet ends have been hammered into place
It’s also possible that the riveted-on base piece of each cauldron is itself a repair. However, the CT images suggest that most of the cauldrons have this element where this part of the bowl survives, and it is also seen on many of the Chiseldon cauldrons, so if this was a repair, it appears to be a common one.
The picture that seems to be emerging is that great care and effort went into the production of these cauldrons, and that they were coveted enough to have been worth repairing time and time again, possibly over a number of years. It is also clear that the making of them was a challenge in itself, even for skilled metalworkers, as repairs appear to have been necessary even while the bowl pieces were being riveted together.
As the remaining eight cauldrons are excavated we hope to learn more about how these observations apply to the group as a whole, as well as to gain a better understanding of the metalworking process used in their creation. As more is revealed about the condition the cauldrons were in when they were buried, it is hoped that this will help us understand how they were used, what for, and the role they played in the lives of the Iron Age people who used them.
The Glenfield Park Project is funded by the developer, Wilson Bowden Developments Ltd. For more information about the cauldrons and their discovery visit the ULAS website.