For the historian of technology, the Encyclopédie is invaluable for the snapshot it provides of eighteenth-century European metallurgy and metalworking technology. Its articles and plates are frequently referenced in studies of French and European metalwork, from the foundry of bells, canons and statuary to jewellery, silversmithing and bronze doré. Dozens of the Encyclopédie’s long-form articles provide detailed descriptions of equipment and processes, while hundreds more short entries describe specific metalsmithing terms, tools and procedures. In my own ongoing collection of articles which refer to metalwork and metallurgy, I have found close to 500 entries so far, but it seems likely that they may amount to a thousand or more. It is indeed a treasure trove of technology.
However, an enquiry into the sources of some of the articles and a critical survey of their scope with reference to surviving metal objects reveals that it may be unwise to assume that metalsmithing technologies described in the Encyclopédie necessarily correlate to those used in Paris or France more broadly during the period, or that a given piece of French metalwork from the period was necessarily made with the techniques described.
Since a number of the articles are translations of foreign works, some may not in fact describe French practices. The article ‘Sable, Fondeur en’ is one of the many Encyclopédie articles translated and adapted from Chambers’ Cyclopædia, in this case a section, ‘Foundry of Small Works, or the Manner of Casting in Sand’, from the article ‘Foundry’. The French article is not entirely a direct translation of the English; the author (possibly Diderot) does elaborate on some parts of the process and describes extra details which indicate that he had indeed visited a sand-casting workshop while preparing the article. However, the French article so closely follows the terminology, descriptions and order of operations in the English that it is unclear to what extent the article actually describes French practices.
In other instances, foreign works were translated without reference to local practices at all, as was apparently the case for ‘Soudure ou souder’, which d’Holbach extracted entirely from a 1760 German work, Ausführliche Beschreibung der Metalllothe und Löthungen by J.G.F. Klein. It may be that French and German soldering recipes and processes were identical, but we cannot assume that this is the case.
While there would have been some degree of homogeneity of metalworking technologies across Europe at the time, largely resulting from the migration of artisans over the preceeding centuries, there were nonetheless some distinct regional practices. A comparison between French and English silver illustrates this point. From at least the mid-17th century, French silver incorporated heavy, highly figurative cast fittings and mouldings, while English silver was generally more restrained in both ornamentation and material, being constructed largely from thin sheet. The influx of Huguenot silversmiths into England in the last quarter of the 17th century before and after the 1685 Revocation of the Edict of Nantes led to the incorporation of heavier cast ornamentation in English silver, but to a limited extent. English patrons were not always enamoured of the busier French style, nor willing to pay greater prices for the extra silver required, and the result was a synthesis of French and English styles. We can infer that a synthesis of technologies took place at the time so that, while English silversmithing technology would now have looked more similar to French technology than it had previously, it would still have been somewhat distinct. One can see how uncritical translations from the Cyclopædia might conflate English and French technologies, which could lead the modern historian astray.
Another concern is missing from the Encyclopédie. Naturally, we do not expect that the encyclopédistes could have described all processes of the mechanical arts, no matter how comprehensive their coverage. However, there is one metalworking process which, to the metal historian, is conspicuous by its absence: small-scale lost-wax casting. The Encyclopédie contains extensive descriptions and plates illustrating lost-wax casting of statuary, almost all of which are taken wholesale from Germain Boffrand’s 1743 Description de ce qui a été pratiqué pour fondre en bronze d'un seul jet la figure équestre de Louis XIV, but there are none describing the use of lost-wax casting in silversmithing or jewellery manufacture, nor even, as far as I can discover, any passing mention of it.
It is difficult to account for this lacuna in the Encyclopédie. It cannot have been left out for fear of repeating the process described for casting of statuary, because small-scale lost-wax casting is quite different, and the encyclopédistes did not shy from repeating themselves over numerous other articles. It is surely not from a deliberate avoidance of the production of luxury goods, because we see detailed discussions of other luxury manufactures such as tapestries, cut diamonds and gilding of metals. We might put it down to the unwillingness of gold- and silversmiths to share trade secrets, but the technique had been widely used for some time, and they were apparently willing to disclose many other techniques.
The significance of lost-wax casting is that it can produce objects which are complex and asymmetrical, such as figures, while the other prevalent technique, sand casting, was largely suited to producing one-sided or bilaterally symmetrical objects. It is curious that lost-wax casting of smaller works is missing from the Encyclopédie because not only had the technique been in common use for at least two centuries but it seems to have flourished particularly during the mid-eighteenth century, especially with the rise of rococo ornamentation. One might even say that rococo metalwork is characteristic of lost-wax casting since the method lends itself to the complex plant and animal ornaments and asymmetrical rocailles which decorate silverware of the period. Modern analysis has shown that bronze doré furniture mounts were sometimes cast by lost-wax, and it was probably common in jewellery manufacture too.
It seems likely, therefore, than it is owing simply to the encyclopédistes’ ignorance of the process, which we cannot hold against them, but it does raise a question about their methods for documenting manufacture. Is it possible that they approached the mechanical arts with preconceived ideas about what processes existed to be documented, perhaps informed by the literature which was already available and which they readily plundered? Rather than visiting workshops to passively observe and record what occurred, or encouraging artisans to speak freely about their work, they may perhaps have arrived with a ‘shopping list’ of techniques to study and describe, essentially filling in blanks in a pre-formed picture.
For the metal historian, the concerns raised here simply highlight the necessity of being judicious when using the Encyclopédie to determine the manufacture of French eighteenth-century artefacts. It is not sufficient to defer to it uncritically; the original source of the information should always be sought out, with attention to the possibility of regionalisation of technology, and there must be an awareness of the material evidence of the artefacts, which can reveal interesting gaps in knowledge and lead to new questions.
– Christina Clarke
Christina is an art historian based in the Centre for Art History and Art Theory at the Australian National University. Christina was a Visiting Academic at the Voltaire Foundation during 2018, funded by an Endeavour Research Fellowship awarded by the Australian Government.