Article published in Du Trenze au Luech, December 2022

Hello Jean-Charles,

You are an archaeologist in CNRS and operations’ manager on the Bocard site.

Can you first explain to us what the IRAMAT laboratory is?

The Institute for Research on Archaeomaterials (UMR 6075) is a unit of the CNRS made up of archaeologists, historians and archaeometers (archéomètres). It includes both humanities and so-called hard-sciences. We study the evolution of the production, dissemination and use of materials in ancient societies, from Prehistory to modern times. (https://iramat.cnrs.fr/) 

Which sections of the Bocard have already been excavated since the beginning in 2017? 

Excavations were focused on the smelter and started in fact in 2016, with borings on the ore roasting furnace and on the blast furnace (four a coupellation). Prospecting had also been carried out in order to identify any signs of mining. In 2017, work resumed in the smelting works, cutting down pine trees and removing the upper layers of rubble resulting from the collapse of the building and a site survey was also carried out.

We came back in 2021 for a total study of the ore-roasting furnace

These operations were conducted by Florian Téreygeol, then Claude Dubois.

What is the aim of these excavations? What are you looking for?

The Bocard is the sole lead-silver foundry still above ground in France and the registration of the site on the list of Historic Monuments since 2014 proves its significance. There are archives dedicated to this site, particularly reports of mining engineering students, but these do not cover the last decade of activity. Moreover, they sometimes contain gaps or even errors. Archaeological excavations allow us the opportunity to supplement our knowledge and to collect materials that will be analyzed in the laboratory. These excavations also fall within the scope of the site’s development program conducted by the townhall of Vialas. 

In November, together with Alexandre Disser, you came without a pickaxe and without a brush, but… with a drone. Can you tell us more about this action?

The aim was to start a 3D-modelling of the site. This first stage focused on the foundry and the smoke condensation chimney.

This 3D modelling technique is called photogrammetry (photogrammétrie) pictures are taken from different angles. In this way, 4500 pictures were taken with the drone, and 1000 shots with a reflex camera in the underground rooms. A software program then makes it possible to compare these pictures in order to gradually recreate the volumes and produce a photorealistic digital model, i.e. on which the texture of the photos is projected. 

Shall we be able to use the 3D- modelling of the factory in the Museum?

Of course. This modelling has three aims: scientific, cultural heritage and public. Scientific, because it is a study support for archaeologists. Cultural heritage because this 3D-model is a digital recording of a site subject to the passage of time, a recording that will be passed on to future generations. And public because it will make it possible to present a virtual model of the site, allowing access to underground rooms, for instance, as well as for the people unable to visit the site.

The Town hall of Vialas is currently carrying out important work to stabilize the foundry’s walls. Despite these endeavors, is the excavation site dangerous? Do you come up against technical problems?

Every archaeological site carries risks, but the one in Vialas is indeed exceptional due to the wall’s height and state of preservation. The Townhall carried out important work to consolidate the remains that will eventually enable us to explore the whole site with confidence.

I think you plan to come back next year… Can you tell us more about that?

I will shortly file a request for an intervention with the DRAC, a request to explore the Litharge Mill (moulin à litharge). We would like to work there for two weeks next autumn, with a small team composed exclusively of professionals.  This team would include archaeologists, mainly specialists in mining and metallurgy, and an industrial designer.

What about the furnace (four a coupellation), last European furnace still above ground?  `

This furnace is indeed very interesting and rather spectacular. While working in 2016, we left, inside the furnace, what we call “an archaeological reserve”, i.e. an unexcavated area. The study of the perimeter of the furnace still remains to be completed. The most urgent, however, is to protect it and the Townhall is aware of this. By the way, I would like to mention the quality of the protection work carried out at the blast furnace (four de grillage).  

In short… we will have many more opportunities to share your projects and discoveries with the readers of Du Trenze au Luech !

Incidentally… would you agree to meet the local residents during your next campaign?

This is possible but let’s wait for the necessary authorizations and funding.

Interview by Mariette Emile, for Le Filon des Anciens, partner of the mining excavations. The excavations are financed by the DRAC, Vialas Town Hall, Lozère Department and Région Occitanie.