I had always wanted to try making a Roman lamp, now that we have an efficient kiln at school. So I did some research on how pottery lamps were made.
Many lamps were mass-produced in plaster or pottery moulds, such as this example from Vindolanda.
I was pleased to discover that the biggest name in factory lamps was Fortis, as seen on this lamp from Modena. It was such a famous brand that other makers forged the stamp on their lamps.
I started with a solid lamp shape made of clay (plasticine would have worked just as well). Then I poured a 2cm layer of plaster into a plastic margarine tub. When that was just set, I put the clay lamp in place, then poured more plaster to half way up the lamp.
I left this layer to set hard then drilled out four holes, about 1cm round and deep, with the tip of a knife. These are sockets, and the upper mould will have lugs to fit them.
I rolled out terracotta clay about 1/2 cm thick, and pressed it tightly into the mould. Then I trimmed the top edges, damped them and put the two mould parts together, fixing them with rubber bands. I left it to dry for several days. The final stage before firing was to drill a wick hole and an air hole. The large hole is used for filling, but it ended up a bit bigger than I wanted it. Finally I fired it.
It took a fair bit of time, but I have been able to make three lamps from the mould so far, and plan to make more when I get round to it!
Minimus would like this beautiful bronze mouse lamp!