31 august 2009

1. The hammer striking process in French medieval mints:study of the amount of scissels in a technical discussion A. Arles*, M. Bompaire*, F. Téreygeol** * IRAMAT - Centre Ernest Babelon, CNRS, Université d’Orléans, France. ** IRAMAT - Laboratoire Métallurgie et Culture and Laboratoire Pierre Süe, CNRS-CEA, UTBM, France. 31 august 2009

2. A global study A technical study of the French medieval hammer minting before the introduction of the balancier process (1645) Blanchet J.‑A., Dieudonné A., Manuel de numismatique française, 4 tomes, Bologne, Italie, Formi Editore, t. 2, 1969, t. 2, p. 23

3. Scissels Strip Squares Blanks The La Rochelle royal mint • Between the XVth and the XVIth century • Many furnaces • Many byproducts of the hammer striking process • The unique medieval French mint excavated until now P. Mille

4. The French medieval minting Experimentations on the paleometallurgical platform of Melle (France) Shearing Alloying Striking Hammering

5. ■ Alloying Casting ■ of the strips ■ Hammering of the strips Hammering Shearing ■ of the squares ■ Beating of the squares Cutting of the squares ■ Flattening of the squares■ ■ Beating of the edges of blanks held in pile Last flattening of the blanks ■ ■ Beating of the blanks held in pile Last annealing ■ ■ Blanching Striking ■ La Rochelle’s artefacts 0 5 cm The hammer striking process To round and... ... to normalize • The interventionism of the minting authorities appears important: • Many controls • Limitation of the amount of scissels • Some steps of the process have to be made several times

6. Rounding cut From the square to the blank • Produce a very large amount of disks from squares of metal with strict metrological expectations • 12,5 % of scissels allowed = limitation ?

7. Sources • Two mint accounts studied by Marc Bompaire: • The Crémieu mint, account1 from the 14th of December 1419 to the 17th of April 1420 • The Bayonne mint, account2 from the 2th of January 1555 to the 11th of August 1556 • The control of the moneyers work allows to evaluate the amount of scissels produced: • Crémieu: 188 counts • Bayonne: 193 counts 1 Archive départementales de l'Isère, B4403, 1420. 2 Archives nationales, Z1b 57, fol. 12, 1556.

8. Fournaise without recuchon Fournaise with recuchon Average (8,6 %) Quota (12,5 %)  limitation Amount of scissels (%) Weight of metal manufactured (marc) Crémieu mint Florette Photo: www.cgb.fr

9. Douzains minting Testons minting Average (23,8 %) Quota (12,5 %) Amount of scissels (%) Weight of metal manufactured (marc) Bayonne mint  tolerance Photos: www.cgb.fr

10. Cutting experimentations • Reconstitution of the whole coining process

11. Beyond the production of a large amount of scissels, the rounding cut process enforce to produce strips with a high demand in their thickness to be minted Weight calibration Weight hard to calibrate The blanks held in pile are beaten on their edges The blanks are beaten individually Schaffhausen window Melle, 2008 The burden of monetary laws on the work of moneyers • The only minting process in accordance with the monetary laws guarantees the quality of the coin in shape and weight • Enforcing a limitation on the scissels production the monetary authorities encourages the use of the right minting process by the moneyers

12. Conclusion • Multidisciplinary approach: • Historical: mint accounts, monetary treatises. • Archaeological • Experimental • A technical discussion allows to understand a monetary law that may appear as a limitation on the work of the moneyers

13. The hammer striking process in French medieval mints: study of the amount of scissels in a technical discussion A. Arles*, M. Bompaire*, F. Téreygeol** * IRAMAT - CNRS, Université d’Orléans. ** IRAMAT - Laboratoire Métallurgie et Culture and Laboratoire Pierre Süe, CNRS-CEA, UTBM, France. email: a.arles@free.fr Address: Centre Ernest Babelon, 3D rue de la Férollerie, 45071 Orléans, France. Thank you for your attention.