Of glass ovens and mines Part 1 : From rumour to reality

 

Rumours

That there was a glass oven on the territory of Perillos has been a certainty for a number of years. Nevertheless, there is a difference between having a certainty and being able to locate it. Furthermore, it is entirely possible that the site was totally destroyed at the end of its operational use, or because of the test of time.
A systematic search was really not possible, even though we realised that the oven could not be too far removed from sites of habitation, as well as a need to be accessible by carriages to bring the raw products and carry away the finished product – all of which could not be done on the back of men. To scan several square kilometres of territory on which the oven could be located meant that this type of exploration was from a practical perspective impossible.
Our hope in discovering the site thus rested on fortune, which on previous occasions had greatly come to our aid. Alternatively, we could hope that the old inhabitants of Opoul-Perillos would remember, or that ancient maps and documents gave us an indication. If the oven would have been located very close the village, then the memories and ancient records would have spoken of it. As for the maps, we indeed found a place identified as “glass oven”, almost straight to the north from the village of Perillos, on grounds that at the time would have belonged to France. As such, it was unlikely that this was the oven that belonged to the community of Perillos – for it was located on the “grounds of the enemy”.

Jewish glaziers?

The little information that the IGN maps provided us with directed us towards the slopes of Montailhou Perilhou. We already knew that in this region there existed a small group of people that lived there. We knew that this small community consisted mainly out of Jews and that the group lived there largely independently, and without having too much contact with the people from the village.
These Jews had lived there for quite some time, in the 17th and 18th century, a period when we find old documents that describe the area with several “Jewish” indications: “la juiverie”, “la juive”, etc. It is clear that these people needed a means of living and thus we assumed that they could live from the profits of their glass making. But, once again, an on site inspection was impossible because though we “only” had to scan the slopes of this mountain, that in itself was acres of land.

Proof in the floor of the church

The existence of a glass oven could, of course, have been just a myth or a local tradition. But there was one important detail that provided us with firm evidence that the story was true. A visitor to the church of Perillos may note that the floor consists of several types of baked earth stones. As a whole, they are not pleasing to the eye. There are stones in different sizes, shapes, colour, etc. But amongst this mass of different stones, there are some that are rectangular in shape. These are also less “matt” than the others – they seem somewhat glossy. This is not because they have been painted or finished with a varnish-type product; instead, the stones themselves had been fired and “glazed”. We note that this type of stone is found in one location, which thus leaves out the possibility that there was a specific decorative intention. We also noted that these stones are not recent additions to the fabric of building and that much of the glazing has worn off over time. Equally, it is a strange type of stone to choose for paving the floor of the chapel. It would crack and break and in essence deteriorate. It appears that these stones were made because they were available at the right time, and for immediate use, whereas other, better suited for this purpose stones were not immediately available.

Those who go hunting… find an oven!

Several people in Opoul knew that we are searching for this site. But for years, the community was unable to provide us with clues or indications, showing that this type of information had disappeared from public awareness, which included the town hall and its records. But a new member of the French Société Perillos, who lives in Opoul and who loves to walk in the area, but also loves to hunt and knows the area almost like the back of his hand… he gave us hope. During one hunt, all of a sudden, he sees his dog disappear in some shrubs. He rushes over to see where his faithful companion has ended up and while removing the shrubs, he sees where his dog has fallen into: a hole. Of course… but not just any hole. He inspects this vertical hole more closely and finds that what he is looking at, is an opening that is man-made, as he can discern from the fact that there are two rows of carefully constructed stones. He passes on this information to us and soon afterwards, we visit the site to make a first inspection.
We soon realise that what he has discovered is that what we have been searching for for years: the glass oven. We also realise that the size of this oven is immense – larger than most ovens of this type. Furthermore, it is quite well preserved and it is clear that nothing has happened here for at least if not more than a century. We decide to make a photographic record of this site and remove some shrubs and loose stones, so that we can do a preliminary inspection. We decide not to reveal its location, as otherwise everything will be ransacked in less than two days.

Operating a glass oven

The required ingredients for a glass oven are normally sand, carbon sodium, dolomite and calcium. Other ingredients and components can be used or part of these ingredients, depending on the needs, region or goal. Many if not all of these ingredients can be found in most places. The “prime matter”, once mixed, the so-called “vitrifiable mixture”, is then placed into the oven, so that it can be baked – fused. The waste product of this process, “the cullet”, can be recycled and is added in certain ratios. Both the mixture and the cullet is entered into the oven, which is required to operate at temperatures above 1500 degrees Celsius.
When the paste has been achieved, the glass is taken off and, at the entrance of the furnace, is ready to be manipulated and to be made into the object that they want to make, from very basic to very sophisticated, whether a glass bottle or an “objet d’art” – though no doubt there was little need in Perillos in the most recent centuries.

Errors and confirmations

When we visited the site, it became obvious that we had made an error as to its location. Broadly speaking, it is located to the southwest of Perillos, several kilometres distant from Montaillou de Perilhou, the location were we had “logically assumed” the site to be. We note that the site nevertheless still conforms to the needs of such an installation: relatively close to roads, even a main road, as well as being close to a “cortal”, i.e. a habitation, similar in nature to the building that is found at the site known as la Mourtre. We assume that there was a relationship between the building and the oven.
We still need to determine the age of the oven, as well as the methods of fabrication and the components used in the glass fabrication. These are not easy challenges.
Arriving at the oven from the west, there is nothing to indicate that this is the location of the glass oven. It is impossible to imagine – unless you know – that a small elevation in the landscape and some shrubs hide the location of this installation. This is no doubt the main reason why the structure has remained intact to this date. There is, in its most immediate vicinity, not a single road or track that would bring someone next to it. Even though the view from the site is delightful, no tourists would ever come here to admire it… or know how to get here.
The opening of the oven is found on the slope of the hill, on the other side from where we approached it. This opening, after removing the shrubs, opens up in a type of corridor, then into a type of dome, whose top is actually open, the walls of which are covered by glazed stones. The presence of this glass confirms, if anyone was still doubtful, that we are indeed confronted with a glass oven.

When one structure hides another one

We returned to the site, to investigate the surrounding area and see whether we could uncover any further evidence, as many questions remained. Roughly five metres down from the oven, we found waste products, the cullet, lying amongst the stones and shrubs. The debris from the oven was obviously carried over a short distance, down the slope, and thrown here. Amongst these waste products were small stones that had turned into glass – but too small to be of any value, except as an archaeological record.
Next, we removed the shrub that had grown over the entrance. When this was done, the vaulted arch of the entrance became visible. We noted that this arch – as well as the structure inside – was double: there was a type of interior part, which seemed to be more ancient and more used, which was then covered by stones that were obviously more recent, and which almost seemed to be a like new layer of covering the older structure. This second series of stones are definitely more recent, but also more difficult to date. They look as if they could have been placed there at any time, from a century ago to five months ago – and we note that the latter is obviously not an archaeological possibility, but merely a visual impression. The second layer of stones seems to have been placed there as a protective blanket, as if at some point in the past, someone wanted to reuse the primitive oven, but decided to consolidate it by this new layer, perhaps designated to keep the heat in or replacing an original coating that had degenerated or even disappeared over time.
The length of the vaulted entrance is approximately 75 centimetres (slightly more than two feet) and is of course equal to the width of walls. The interior is now exposed to the elements, and it seems that the original dome either collapsed or was at some point removed. The inside measures ca. 1.5 metres, or 5 feet – which is similar to its height. This reveals that the workmen of the oven could easily enter the structure to carry out all types of maintenance and inspection work that this oven required.

The preliminary end

A third visit to the site was to complete the cleaning of the shrubs from the entrance and do further inspections of the area. It was then that we found, scattered on the surface of the entrance and somewhat deeper inside the oven, a multitude of animal bones. No doubt these are the remains of the diet of other animals, who used the oven as their dining room or restaurant… or as a place to die. We also noted that the entrance seemed to descend slightly and that the entrance was of sufficient height that an adult man would be able to walk inside. This conclusion is based on a suggestion that the structure goes deeper into the ground, but for this, some archaeological research will need to be carried out to (in)validate this. At present, a person can merely slide himself inside the structure, meaning that the opening would enter at least one meter under the present soil level. This is a physical possibility, but only archaeological tests can provide the answer.
As we are not qualified or licensed archaeologists, this is where our research had to end, if only for legal reasons, but also because we do not have the tools or physical manpower to carry out such investigations. We hence could not – nor want to – go beyond this stage.

Making good use of a glass oven

We can, nevertheless, add some intriguing comments. As mentioned, during our initial inspection, we found the presence of several stones that had been clearly subjected to intense heat, resulting in them receiving a layer of “glass” on one – the exposed – side. The stones on the inside of the dome are equally glazed, which provides evidence that extreme heat was produced inside the structure.
Some questions do nevertheless remain, specifically following our third and final visit to the site. These questions have to do with the original structure. Could this original structure have been an oven, or was it something else? Let us repeat that there is no doubt in our minds that this structure was used as an oven. The question is whether the original building was built as oven, or was originally used for something else, and then later used as an oven.
We should also add that in the vicinity, we could not find any evidence of the paste to make glass or of any of the other metals required, or products to make the fire. Whereas the latter may have failed the test of time, the former should have been able to somewhat withstand them. Though we also found evidence of the cullet, we would expect more waste to be found, though we neither mounted an intensive search, nor were we able to investigate the possibility that the cullet was reused in some construction elsewhere.
Next, we should note that an oven of this type must – can only – have created a steady production line. It is to be expected that some memory or traces would remain present in the village. Instead, there is no such thing… not even of its location. It is almost as if this glass production occurred illegally or discretely, which would be the most logical reasons why it is absent from local memory – but which is at the same time the most illogical conclusion to draw, for what is secretive or illegal about glass production? Furthermore, the floor of the church of Perillos shows that the local people and powerbrokers knew of its existence at some point and used it.
Finally, let us note one further oddity about the glaziers themselves. It is known that glaziers – master glaziers – “carried the sword” and were normally treated on equal basis as nobility. They were experts tradesmen, did not come cheap, were treated with respect and lived accordingly. The nearby cortal may provide them with an apt home to live in, but we would equally assume that some further trace of their presence would exist – specifically if, as would be logical to assume, there was a production here for more than one generation.

Though we have found the location of the glass oven, as is usual, each discovery posses further questions.

continued>>

André Douzet & Filip Coppens