Experiments in the creation of beads using Viking-Era Norse techniques

This section of the site will showcase the experimental bead melts we have made. These experiments are based on archaeological evidence, and are targeted to recreate the techniques the Viking Era Norse used to make beads.

On the menu to the left are

• Links to each of our experimental melts
• The archaeology page summarizes the archaeological remains and is most in need of an update.
• The bibliography page has an annotated biliography of books and articles.
• Crafts in Ribe is a translation of an article on the bead production at Ribe.
• Glass Beads is a discussion of the glass beads found in viking era graves as recorded in Callmer's Trade Beads. This book contains records of almost 15000 beads from nearly 300 finds. The Glass Beads article provides some statistical information about the beads and finds (common colours, sizes, images, and even includes shopping hints).
• Stone Beads provides similar information with regards to stone beads.
• The Bead Summary provides shape and colour based charts summarizing the types of monochromatic beads found.
• Small Summary is a more printer friendly version of the bead summary.
• The Bead Classifier is an experimental page that will help you match existing beads to specific Callmer classes. It is a work in progress and will be for some time to come.

We get a number of emails asking why we make some of the choices that we do in our experiments. This can best be explained by providing a background on what we are doing and why. This section of our website records a sequence of experiments designed to bring us to an understanding of at least one method the Viking Era Norse could have used to produce beads. There is, of course, no way for us to prove that the method we eventually produce was used. Our goal is to get a method that: 1. reliably produces beads, 2. uses equipment that would have been available and, 3. that matches the archaeological record that we have with regards to beads produced, furnace, surrounding area layout, and materials.

Our research on artefact remains is summarized on the archaeology page. As it shows there are a few clay bases, some with clay/ceramic on them, and a number of tools. This may indicate that the smelter was made of rock which was taken away to be reused, or that it was made of cobb (clay / sand / straw mixes). Within these constraints, there can further be a range of sizes - the size of the base being all that can be ascertained from the remains.

At these sites we find charcoal remains, and debris (the left over bits that come from making beads).

We are coming to understand the physical relationship between glass, furnace, and charcoal. The layout of the furnace is effected by the nature of the material used to construct it, and it's specific use. Air volume drives the physical environment inside the furnace. Unfortunately, no actual air delivery system survives from the dark ages, but it is a reasonable assumption that some kind of forced air bellows system must have been used.

Extrapolating from blacksmith's work, this implies that they used a bellows powered forced air and charcoal system to melt the glass so that it could be shaped into beads.

We often get teased about our use of mechanical blowers rather than bellows although we have used various bellows systems many times in our iron and bead experiments. Using a mechanical blower allows us to fix the amount of air moving into the furnace without having to worry about operator fatigue, different operators producing different levels of air, the changeover between operators causing a cooling, and so on. We have experienced all of these problems from time to time when we used bellows. Since we have worked with bellows in the past successfully the use of a blower simply allows us to focus our scarce resources on more interesting problems and we certainly aren't short of those. It is worth mentioning that this sort of experiment is often more difficult than people realize, and often in very subtle ways. The bellows is a good example of this sort of complexity. To begin with, there are no surviving examples of norse bellows. This means that before we can use them we need to figure out what they looked like. There are, thankfully, a couple of carvings of bellows, although these are blacksmith's, not iron smelting or bead making, equipment. Both carvings are very simplistic but it is possible to see that they were using a two lobed bellows like you will see in our pages. They do not, however, come with good measurements. Since the size of the bellows directly affects the amount of air produced this is an important question. Many tiny things about a bellows (hinge method, height off ground, total lift on the lobe, size of air input, size of air output) can all impact the pressure and amount of air delivered to the furnace.

The list of questions we are exploring, will of course change from time to time as we answer some of them and others occur. The following are the questions for which we are seeking to find answers. Where answers are known we have moved the question over to the Q&A page.

• With regards to the Ribe furnace bases
  • Are there left over bits of glass from within the furnace (see this image)?
• What patterns of breakage are visible in the bead debris?
• Are there traces of ash on the whole or partial beads? (Yes)
• What material lines the mandrel holes in the beads? Some beads do show traces of a lining - see especially the Gotland beads in Dr. Carlson's work (link).
     preliminary checks of the Beads found in the Mosfell digs in 2007 and 2008 do not seem to indicate any residue from a clay slip - R Bathurst (Pers.Comm.)
• Is the glass inside the mandrel hole smooth or rough? (rough might indicate a clay slip, smooth is less obvious)
• What is the temperature in the annealing pots?
• Record temperatures in various locations of each furnace, each burn, with different air sources
• With regards to the tesserae
  • what size are the tesserae?
  • when heating tesserae on charcoal
    • what trace is left behind?
    • is that trace matched in the record?
  • when heating tesserae on soapstone
    • what trace is left behind?
    • is that trace matched in the record?
  • when heating tesserae in crucibles and drawing stringers
    • what trace is left behind?
    • is that trace matched in the record?
• What tools are supported/required?
• Can some tools be replaced with green twigs?
• What marvers are required?
• What materials work for the marvers?
• Can a knife be used to shape beads?
• Do melon beads show traces of marver or knife?
• What work flaws exist in beads? (ash marks?)

Future years will likely involve the following experiments.

Working Temperatures

In 2011 we did some focused work around recording temperatures (see the links on the left). We need to follow that up with a single day recording multiple cycles from each furnace including weighing the charcoal to begin to understand efficiency.

Fire Handling

We need to spend some focused time working on fire handling. The beads need a fairly solid level of heat to stay workable. With charcoal the temperature can change fast. In addition we need to keep loose ash under control so that it does not wind up making contact with the glass. Finally if we are going to use charcoal as a base to heat tesserae this adds a level of complexity to the fire control. It is convenient that we have an experienced blacksmith who can work with us to develop this skill.

Annealing

This is clearly a problem area. Temperature readings will help but we need to develop a method that will improve our survival rate before we can move on to a broader mix of glass

If you have any questions about our bead making experiments please email us.