Last time we talked a little about making glass beads in a period manner. There are an interesting assortment of bead kiln designs documented online. I am, of course, most interested in designs that have been tried. Even failures can teach us something if we keep good records.

Before we go any further I need to introduce you to a group that is into serious research – the Dark Ages Recreation Company – a group of very authenticity oriented Canadian reenactors. This article documents several different designs of kilns that were made and tried by members of DARC.

And a quick note about the use of glass in ancient times. The actual manufacturing process of glass is a labor, and fuel intensive, process. There are four common sources of glass available for pre-1600 artisans:

1. broken glass – Broken glass items are simply re-melted and made into new glass items.
2. tesseri – The glass pieces that the Romans used in Mosaics were melted down and made into beads or used as enamel (a common practice in the Middle Ages).
3. glass rods – Generally imported from Italy, these are the same sort of hand pulled glass rods that modern glass workers use to make beads and other objects.
4. glass cakes – Blocks of glass that were easy to ship. These blocks needed to be melted in a crucible in a glass furnace before they could be used. We have archaeological evidence for the blocks on shipwrecks in the Mediterranean.

And back to the research aspects…

One of the first videos that I ever ran across on bead furnaces was made by DARC. The video is still online and shows the use of tesseri to make a glass bead. There is not much commentary, but the viewer should remember that the temperatures that are mentioned are in Centigrade.

The Dark Ages Recreation Company based their work mainly on the archaeology of Ribe, Denmark, which does appear to have one of the largest collections of glass fragments, broken beads, clay pads, etc. in a Viking Age site. Indicating the probable presence of glass bead manufacturing facilities. Their website is an excellent source of bibliographic information on glass bead making. It also details a lot of the other projects that they have underway. DARC provides living history displays for Canadian Museums on a regular basis. They are frank and honest about the fact that some of the sections of the website are not up to date, and that the archaeological record does not give us clear information on how glass kilns were made during Viking times.

And an exciting bit of information about a very reasonably priced new book on glass working, published by Museum of London Archaeology and available through Casemate Academic (formerly Davis Brown Book Company). Glass Working on the Margins of Roman London reports on the excavation of a site in England that yielded over 75 kg (over 165 pounds) of glass debris. Roman glass working was a well-developed craft, which predates the Vikings by centuries, but the fact that serious studies of glass working areas is happening is a hopeful bit of progress!

Next time: But what about the iron smelting furnace?