Category Archives: Experimentation

Counting on the body: Reflections on Numeracy in Indian dyeing practices

By Annapurna Mamidipudi

‘I don’t know how to read, but I can count’ said Salim, ‘I was not much for school, my father put me on an old tractor when I was 12, and told me to go around in circles, till I had learned to drive’. Salim was a 20 something driver, the same age as me, when I met him in 1990. I –along with a few other socially minded engineers – was trying to decipher the recipes from a century old colonial account of dyeing using natural materials, and he was hired to drive me around the weaver villages we were visiting in rural Andhra Pradesh in South India.  The idea was to use these recipes to bring natural dyeing practices lost over the last century back into the practice of craftspeople, in order to enter newly emerging green markets and support their livelihoods.

‘Keep the temperature around 70 degrees’ specifies the recipe. Yes, I could measure the temperature and tell when it was 70 degrees; but how to maintain a constant one? Salim smoked incessantly, yet he could blow on an open wood fire under the dyebath to keep it at a steady 70 degrees for as long as it took to extract the colour –whether yellow, brown or red. I measured and jotted down notes from his experiments, attempting to standardise a recipe that would provide fast colour across the different dyehouses, in the different villages where craftspeople were being trained to re learn natural dyeing practices. But this was an important first lesson about the material life of numbers in dyeing –they came attached with fires, smoke, dye baths, and always required a willing body to maintain them.

Indigo dyed yarn production in a weaver co-operative dyehouse © Moody Chetanand

So my first recipe:

Material needed:

For one kg. of yarn, take  15%  in weight in dyematerial Katha [Acasia Katechu]

Copper Sulphate: Take 10 % of weight of dye material

First measure out the quantity of dye material…….

‘Weavers don’t read, why would you want to write down a recipe in English?’ Salim interrupts, with some curiosity. The recipe is a formula, I explain, and it has to hold fast wherever we use it, and whoever uses it. It can be in any language, its the numbers and reproducibility that make it technical. ‘My car is technical, but I don’t need a manual’ he jokes, even as he measures out quantities out aloud for me to write into the journal we keep of all the dye experiments. After using the recipe on the field in a series of training workshops for weavers, he makes an observation. ‘Change the recipe standard to 4.5 kg, not one kg, if you want a stardardised recipe’. I reply patiently, if they learn to calculate quantities using the standard of 1 kg, they can multiply it by 4.5 or any number they chose, that’s the whole point of a recipe. ‘But they only use the 4.5 kg standard, or multiples of it, so if you write those down in the recipe, they don’t need to learn how to calculate percentages’. He is right, I realise, all across the world of Indian cotton handloom weaving, the general measure that applies across all dyehouses, is the weight of one box of cotton yarn, the ‘peti’, standardised across all thicknesses or counts of yarn. I change the recipe; we now formulate all recipes with 4.5 kg as the base. I need a calculator to figure out how much copper sulphate we need for the recipe for Katha, each time, meanwhile, Salim is measuring it out by hand. ‘Sometimes the quality is not so good, you have to add a bit more’. The weavers agree, accuracy is about the outcome of colour, not so much the weight of material as input.

Sample of jottings from a dyehouse in Peddapuram in Andhra Pradesh © Moody Chetanand

Almost ten years later, Salim is a master dyer, and well on his way to acquiring the skill of dyeing Indigo, one of the most difficult colours to master. He is successful in the market, and has trained more than a hundred artisan groups, forming a large network of dyers. I continue to be the documenter of recipes, now trying to author a small booklet of recipes in the four South Indian vernacular languages, for craftspeople learning natural dye colours. ‘You tell colour by smell, put away the notebook’, he says. Yet, in Salim’s pocket is a strip of paper that can measure the pH value of a solution; ‘Checking the Indigo vat with a pH paper helps me to get a general idea of how alkaline the vat is, before I start using my nose,’ he says. He is meticulous in checking the vats every morning and evening. ‘Yellappa is a master, [the 80 year old Indigo dyer who taught Salim] he doesn’t need the paper’, he says, a little enviously, ‘he can count on his nose to tell him when the vat is ready’. We decide to leave out the recipe for Indigo from the booklet, learning to tell colour and alkalinity by smell has to be learned from the master, not with recipes.

Salim setting up the Indigo vats in his dyehouse © Moody Chetanand

Ten years on, it is 2012, and I am theorising innovation in craft practices, as part of my PhD study –analysing the practices of dyers as socio-technical expertise. I am assailed by the smell of fermenting Indigo, as I enter the well functioning Indigo dyehouse for an interview with Salim the master dyer. Salim is a tad more portly, and is surrounded by a bevy of young men and women dyeing Indigo. ‘Come to learn Indigo dyeing?’ he asks with a smile. I take out my laptop, ‘put your hand in’ he says instead, ‘and turn the yarn 50 times’. I wet the hank of cotton yarn, and sit down amongst the other dyers. Unpractised as I am, I lose count after 37, but Salim tells me when I can stop, he can see when the colour is right.  Do you keep count? I ask the girl sitting next to me, curiously. ‘I used to’ she says, ‘now my body knows how long it takes, so the numbers disappear from my mind’.

Indigo dyeing: Dyehouse of Salim © Moody Chetanand

I reflect later, on how to write the recipe for Salim’s Indigo, and who to write it for. The underlying chemical principles of the traditional fermentation Indigo vat have been written up extensively by scholars and scientists. The aim of my own analysis was to establish that Salim like many other master dyers before and after him has indeed mastered the principles of Indigo dyeing. How does one establish that, without explicating his knowledge in scientific terms? Yet, even if I were to explicate such a recipe, Salim himself would not use it. Rather, he engages his material knowledge of Indigo as he problem solves, or sets up a new vat, or uses new materials to bring forth a resplendent blue time after time.

Where then does the knowledge of the underlying principle reside in his practice? I do not yet have an answer. All I can speculate is that the knowledge of the principles governing Indigo are known by Salim much like the numbers themselves are known in the dyeing: when dyers learn to count on their bodies, the numbers on the piece of paper disappear. Much like a weft thread woven through the warp, sometimes visible on the surface of the fabric, and at other times stabilised below the threads, Salim’s knowledge too is always present, sometimes visible and enumerable, and at other times invisible and embodied.


Annapurna Mamidipudi was trained as an engineer in electronics and communications, in Manipal, in South India. She had set up and worked for over 15 years in an NGO that supported vulnerable craft livelihoods where before completing her doctoral thesis titled “Towards a theory of innovation for handloom weaving in India” in the University of Maastricht in 2016. She is currently a visiting post doctoral fellow at the Max Planck Institute for the History of Science. She is a member of the NGO Timbaktu Collective’s executive committee, which works in the drought prone district of Anantapur in Andhra Pradesh to support women farmers and trustee of the Handloom Futures Trust, in Hyderabad.

Books of Secrets

By Mandy Aftel

From Fragrant:The Secret Life of Scent by Mandy Aftel

Alession Piemontese Frontispiece

In the early sixteenth century, a new kind of book appeared in Europe: Books of Secrets were popular compendiums that professed to divulge to the reader the secrets of nature, culled from ancient sources of knowledge and wisdom. The most famous was The Secrets of Alexis of Piedmont, the pseudonym of an Italian physician and alchemist. More than seventy editions were published in at least seven languages, including my personal copy of the 1595 English edition. A third of the book was taken up with formulas that were not culinary but medicinal, remedies for common ailments. There was a chapter of recipes for perfumes and other scented ingredients—lotions, soaps, and body powders. And it wasn’t only the culinary and perfume recipes that called for spices and natural essences. There was a mouthwash of benzoin, cinnamon, rosemary, and myrrh, for example.[i]

These books’ closest descendant in the modern world is the cookbook. But the very idea of a cookbook is a recent one. To the pre-modern mind, there was no clear distinction between food and medicine and craft, the domestic and healing and creative arts. Substances derived from plants and animals and minerals were “simples”—building blocks that could be combined to form different compounds. “Pharmacists had to know how to grind up mixtures of simples according to medical instructions or their own ingenuity,” writes Paul Freedman in Out of the East. “Pounding and grinding together these aromatic products was a tedious task and became a symbol of the art and labor of the medical or culinary expert in spices, the cook and the pharmacist.”

When I discovered the Books of Secrets, I was smitten not only by their wealth of useful knowledge but by their charm. Their primordial scrambling of appetites and arts mirrored the synesthetic nature of the senses. Here home remedies mingled with folk wisdom, traditional knowledge with family lore. They combined the seemingly contradictory strands of the practical and the mystical in a way that reminded me of perfume, which—for all the formulas generated in all the labs in all the fragrance houses—can never be reduced to a science. Indeed, herbs, flowers, and spices played a great role in the arts they covered, and so the books focused on the same ingredients that are used to create natural perfumes.

I’d reveled in the same promiscuous muddling of material in my library of antique perfume books, in which fragrance recipes rubbed shoulders with alchemy, folk remedies, and precursor versions of aromatherapy. But when I tried to use the recipes in a straightforward way—as if from a cookbook, I discovered something interesting.

I’d always thought, in the back of my mind, that if I ran out of ideas for new perfumes, I could use the recipes in these books to replicate the perfumes that used to be made—though I had not quite figured out how I would find, or afford, the copious amounts of musk and ambergris so many of the recipes called for. One day I decided to put that idea to the test and start making the perfumes in some of my old recipe books.

Handwritten Formula Book from 1838

Many of the formulas were for what were known as soliflors, the attempt to replicate the aroma of a delicate flower that couldn’t be scent-harvested, like lily of the valley or violet; they seemed to rely heavily on bitter almond, which smells like cherries, to convey the nuance of flowers. When I made a couple of the perfumes, however, they struck me as decidedly “old lady” and uninteresting. Moreover, as I combed through the books, giving the recipes a closer look, I realized that the recipes had frequently been copied from one book to another. Over time, presumably by being carelessly recopied by scribes who didn’t understand the processes behind the words they were transcribing, many of the recipes had become garbled in places, or completely unintelligible. None of this stopped me from regarding these antique books as important links to a remote and rich past, initiating me into the mysteries of antiquity. In fact, I realized that their true genius lay not in their formulas but in the world they conveyed, a lost world of eccentric personalities consumed with the passion for travel to uncharted places, in search of undiscovered treasures and exotic substances. And the most important “secret” they contained was an alternate way of looking at the world—an aura of romance, sensuality, adventure and creativity.

Perfumers Notebook 1876

As for the recipes, they taught me something too—not how to replicate the perfumes of the past, but how to regard the process of making things and passing on knowledge about that process. The recipes in these books had the patina of having been forged in a crucible of trial and error by real-life practitioners who were passing on their hard-won knowledge to like-minded artisans. But recipes, even faithfully copied, cannot convey the deeply personal, idiosyncratic processes out of which they were distilled. “Recipes collapse lived experience into a series of mechanical acts that, once parsed, anyone can follow,” Eamon observes. “While a ‘secret’ is someone’s private property or the property of a group, a recipe doesn’t belong to anyone. Once it is published, someone else appropriates it, uses it, varies it, and then passes it on. At each stop it gains something or loses something, is improved upon or degraded, and is changed to fit new needs and circumstances. Recipes are built upon the belief that somewhere at the beginning of the chain there is someone who does not use them.”[ii]

Inherent in the Books of Secrets were attitudes and beliefs that grew out of the medieval imagination and resonated deeply with my work as an artisan perfumer. They reflected a belief in “Maker’s knowledge” (verum factum), which means that to know something means knowing how to make it. Such expertise cannot be acquired from someone else’s experience, but must be accrued by handling, experimenting with, and learning from the materials themselves. The search for how to do something was an essential part of the process, and it even had a name: venatio, “the hunt,” which referred to the hunt after the secrets of nature. Venatio was exactly what I experienced when I was searching for the lost knowledge of natural perfumery.


Mandy Aftel is an artisan perfumer who has published on scent and flavour. She also has a small museum, The Aftel Archive of Curious Scents. (Details here.) The above excerpt is from her award-winning book, Fragrant:The Secret Life of Scent (Penguin, 2014). You can purchase her books here.

How to Sublime Mercury: Reading Like a Philosopher in Medieval Europe

This month, we’re excited to collaborate with History of Knowledge to celebrate the upcoming conference, Learning by the Book: Manuals and Handbooks in the History of Knowledge. The five-day event takes place at Princeton in June and features a “blogged conference” to complement traditional panel presentations. For the next few Thursdays, the Recipes Project will cross-post selections from the conference (with RP readers noting  the extended length, in keeping with HoK posts). These features are just a taste of more than thirty works produced for the conference, and readers are invited to read the full selection here. Enjoy!

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Jennifer M. Rampling

When it comes to “how-to” books, alchemy poses particular problems. Medieval alchemical treatises claimed to offer detailed advice on a host of spectacular products and processes, ranging from the Philosophers’ Stone, a transmuting agent capable of turning base metals into gold and silver, to medicinal elixirs that offered cures for otherwise intractable diseases, as well as the prospect of renewed youth and an extended life span. Yet, at least to modern eyes, no amount of “know-how” could teach anyone how to make these things — they are impossible practices, which no alchemist can ever have successfully carried out, nor described in accurate, replicable instructions. What, then, is the function of a “manual” of alchemy?

First, many of the early readers who studied alchemical writings did consider these ends to be obtainable, while recognizing that their sources might not always include complete or accurate information. Even seemingly straightforward processes can be difficult to reproduce in practice. For instance, the Liber de aluminibus et salibus (Book of Alums and Salts), a Latin treatise translated from an Arabic exemplar and pseudonymously attributed to the Persian polymath al-Rāzī, includes a simple procedure for subliming mercury with vitriol (a metal sulphate) and “common” or “general” salt.[1] According to the text, this mixture will sublime to the top of the vessel in the form of “white and shining” crystals, a description that sounds a lot like corrosive sublimate (mercuric chloride, in modern parlance).

As it happens, corrosive sublimate was a staple ingredient of fourteenth- and fifteenth-century alchemy, although its manufacture normally requires a nitrous salt, such as saltpeter, rather than common salt. Working with Professor Lawrence Principe at the Johns Hopkins University, I have attempted to solve this puzzle by following al-Rāzī’s laconic instructions in a modern laboratory setting.

Figure 1. Grinding quicksilver, vitriol, and salt with mortar and pestle. Copyright of the author.
Figure 1. Grinding quicksilver, vitriol, and salt with mortar and pestle. Copyright of the author.

The Liber directs us to take as much quicksilver as we want, then grind it with equal quantities of vitriol and salt until the quicksilver “dies” in them — that is, until globules of mercury are no longer visible in the mixture. But does “quantity” refer to weight or volume? Although the recipe does not say, the answer must be weight, since measurement by volume results in an excess of quicksilver, which stubbornly refuses to die:

Figure 2. Excess quicksilver. Copyright of the author.
Figure 2. Excess quicksilver. Copyright of the author.

Once we have killed our quicksilver (the Liber tells us), we should leave the mixture in a bread oven overnight. In the morning, we moisten it with salt solution before returning it to the oven. We repeat the cycle of moistening and overnight heating until the mixture has tarnished to a reddish colour (an effect caused by the rusting of iron in the vitriol). Later recipes refine this process, suggesting different ways of achieving the same result. One Middle English procedure recommends grinding the mixture several times a day for two to three days, with “esy dryynge and moysty[n]g with a lytel vynegre.”[2] Another advises scooping the mixture onto an old potsherd and stirring it over hot embers until no moisture remains.[3] We left ours on a low heat overnight.

Figure 3. The mixture after being left overnight on a low heat. Copyright of the author.
Figure 3. The mixture after being left overnight on a low heat. Copyright of the author.

The mixture is now ready to be sublimed. According to pseudo-Rāzī, it should be placed in an aludel, sealed, and heated (a process that takes longer in winter than in summer). We must use a soft rather than a hasty fire. Otherwise, as one fifteenth-century writer warns, the quicksilver will lose its active power and sublime in its “crude” form — a hazard that can easily be replicated in a modern laboratory. If performed correctly, the mixture sublimes into a substance as “white as milk.”[4]

Figure 4. Sublimation in a glass aludel over gentle heat. Copyright of the author.
Figure 4. Sublimation in a glass aludel over gentle heat. Copyright of the author.

This is the point when our reconstruction foundered. As already noted, corrosive sublimate requires a nitrous salt — common salt, as specified in both the Liber and the Middle English variants, should not work. In fact, our practice based on common salt conspicuously failed to generate any white crystals.

On the other hand, replacing the NaCl with sal niter immediately produced the desired effect:

Figure 5. Lawrence Principe removes corrosive sublimate from the aludel head. Copyright of the author.
Figure 5. Lawrence Principe removes corrosive sublimate from the aludel head. Copyright of the author.

 

Figure 6. White crystals of corrosive sublimate. Copyright of the author.
Figure 6. White crystals of corrosive sublimate. Copyright of the author.

Our initial failure illustrates the difficulty of precisely identifying ingredients from alchemical texts. Making corrosive sublimate seems to rely on an ability to distinguish between the properties of different salts, but can we acquire that knowledge entirely from books? Perhaps lack of technical expertise explains the “transmutation” of sal niter into common salt as a transcription error made by a scribe unversed in chemical procedures. Alternatively, our saline setbacks may result from our own lack of experience with this type of procedure.

We are certainly not the first experimenters to face this dilemma. Medieval and early modern recipe collections contain hundreds of procedures for subliming mercury, involving diverse salts and methods of preparation, and no doubt resulting in a variety of chemical products (even pseudo-Rāzī follows up his common salt recipe with a variant using sal ammoniac [5]). But readers also knew that not all recipes were reliable. As the English alchemist Thomas Norton warned the readers of his Ordinal of Alchemy (1477):

Avoide youre bokis writen of receytis,

For al such receptis be ful of deceytis.[6]

Norton was suspicious of recipes precisely because they offered fixed, literal readings of ingredients — but such readings could be wrong. The writers of alchemical treatises typically chose to present themselves as philosophers rather than artisans, whose knowledge stemmed from a profound understanding of nature gleaned not only from practice, but also from studying the writings of past authorities. These “philosophers” emphasized the privileged nature of alchemical knowledge and the need to preserve its secrets from impious or otherwise undeserving readers: an injunction manifested in their use of cover names, allegories, and other methods of obfuscation. In the hands of a self-identified alchemical philosopher, a term like “mercury” could take on almost as many identities as there are chemical substances.

This strategy placed a burden on readers, who sought to disentangle practical instruction from a web of possible meanings. Take, for instance, the opening procedure in one of the most influential works of Latin alchemy: the Testamentum. This lengthy treatise, probably written in the 1330s by a follower of the Catalan philosopher Ramon Llull (ca. 1232–ca. 1315), uses Lullian style diagrams to express alchemical doctrines and practices.[7] Here the writer plots his ingredients onto an alphabetical wheel:

Figure 7. Pseudo-Lullian wheel from the Practica Testamenti. New Haven, Yale University, Beinecke Rare Books & Manuscripts Library, MS Mellon 12 (mid. 15th cent.), fol. 97v. Courtesy of the Beinecke Library.
Figure 7. Pseudo-Lullian wheel from the Practica Testamenti. New Haven, Yale University, Beinecke Rare Books & Manuscripts Library, MS Mellon 12 (mid. 15th cent.), fol. 97v. Courtesy of the Beinecke Library.

The wheel begins with “A” (Deus), signifying God. The practice starts with B (defined in both text and diagram as quicksilver), C (saltpeter), and D (vitriol azoqueus), a combination that strongly hints at the making of corrosive sublimate. Has the author of the text simply decked a simple procedure in the garb of Lullian philosophy? Or are the terms merely cover names for other substances, as suggested by the fact that vitriol is qualified as “azoqueus”?

A naive reader may have tried to follow the instructions as they stand. A reader more familiar with the conventions of alchemical writing might regard several of the terms with suspicion. Is ordinary mercury intended, for instance, or does B denote some other “mercury”? And if a procedure fails to work, who is to blame — the authority for setting down a faulty procedure or the reader for supplying a faulty interpretation? Under such circumstances, what the novice alchemist really needs is not a manual of chemical practice, but advice on how to read such practices in a philosophical way. It is in this regard that works like the Testamentum truly come into their own.

 

I am grateful to Professor Lawrence Principe (Johns Hopkins University) and to the David A. Gardner ’69 Magic Project (Princeton University) for supporting the experimental reconstructions detailed above.

[1] Ps. Razi, Liber de aluminibus et salibus, in Robert Steele, “Practical Chemistry in the Twelfth Century. Rasis de aluminibus et salibus,” Isis 12, 1 (1929): 10-46, on p. 24; see also Julius Ruska, Das Buch der Alaune und Salze. Ein Grundwerk der spätlateinisches Alchimie (Berlin: Verlag Chemie, 1935). The Arabic version of the text is currently being edited by Gabriele Ferrario.

[2] Oxford, Bodleian Library, MS Ashmole 1451, fol. 5v.

[3] Oxford, Bodleian Library, MS Ashmole 759, fol. 42r.

[4] MS Ashmole 759, fol. 42v.

[5] Steele, “Practical Chemistry,” 24.

[6] Thomas Norton’s Ordinal of Alchemy, ed. John Reidy (London: Published for the Early English Text Society by the Oxford University Press, 1975), 7.

[7] On the Testamentum and its author, see Michela Pereira and Barbara Spaggiari, Il Testamentum alchemico attribuito a Raimondo Lullo: Edizione del testo latino e catalano dal manoscritto Oxford, Corpus Christi College, 255 (Florence: SISMEL, 1999).

 

Blog Series: Learning by the Book

Join the conversation on Twitter with the hashtag #lbtb18. Tweet or email links to related discussions. Read more posts in this series, and check out the conference website.

Vicissitudes in Soldering. Reading and Working with a Historical Gold- and Silversmithing Manual

This month, we’re excited to collaborate with History of Knowledge to celebrate the upcoming conference, Learning by the Book: Manuals and Handbooks in the History of Knowledge. The five-day event takes place at Princeton in June and features a “blogged conference” to complement traditional panel presentations. For the next few Thursdays, the Recipes Project will cross-post selections from the conference (with RP readers noting  the extended length, in keeping with HoK posts). These features are just a taste of more than thirty works produced for the conference, and readers are invited to read the full selection here. Enjoy!

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Thijs Hagendijk and Tonny Beentjes

In 1721, the Dutch craftsman Willem van Laer (1674-1722) published a Guidebook for Upcoming Gold- and Silversmiths. Intended as a manual to educate young novices, the Guidebook discussed a variety of different practices, techniques, and skills that ranged from assays to determine the quality of precious metals to sand mold casting and polishing (Figure 1). Four different editions, including one pirated copy, appeared in less than fifty years, attesting to its popularity. The book was explicitly aimed at teaching young readers how to do and make things. Van Laer reassured readers by saying “there will be few young gold- or silversmiths, who won’t find anything to their liking and benefit while reading this book; they will be led by hand to the knowledge of many things.”[1] Yet, however confident Van Laer might come across in this passage, there is sufficient reason to question the actual success of Guidebook at explaining and delivering these skills. Practical knowledge is often better demonstrated than written down. Van Laer was very well aware of this fact and offered disclaimers warning his readers that full comprehension of the text was only achieved when complemented with manual instruction. This begs the question of what could, in fact, be learned from the Guidebook.

Figure 1. Title page of the Guidebook. Copy held by the Rijksmuseum Research Library, Amsterdam. (Call number: 305 E 33). Photo by Thijs Hagendijk.
Figure 1. Title page of the Guidebook. Copy held by the Rijksmuseum Research Library, Amsterdam. (Call number: 305 E 33). Photo by Thijs Hagendijk.

The best way to answer this question is to look at historical evidence, primarily in the form of marginalia or other signs of usage, that indicates how the Guidebook was read and used on the shop floor. Unfortunately, not much of this evidence has survived for reasons that historians Natasha Glaisyer and Sara Pennell have observed in their study of early modern didactic literature. They note an irony in the fact that books that were most read and used did not make it to our libraries.[2] Indeed, most Guidebooks that reside in Dutch libraries are neat and almost spotless copies – we even found a copy with its pages still uncut! (We ended up cutting its pages almost three hundred years after publication, but that is another story). This virtual lack of historical evidence pushed us in a different direction. We decided to approach the Guidebook experimentally by performing historical re-enactments. By reading and working with the text as if we were learning how to make and do things, we were able to get a better grasp of Van Laer’s potential audience and the role the book might have played in historical learning practices and the acquisition of practical skills. The re-enactments gave rise to various insights.[3] In this post, we discuss one specific result, which is a story involving both success and failure.

Part of Van Laer’s discussion of soldering features the introduction of a “convenient soldering lamp.” Even though the better part of soldering usually happened in the forge, Van Laer presents his soldering lamp so that “the maker won’t need to put the entire piece back into the fire for a tiny leak or mistake only.”[4] For a silversmith, putting a soldered piece back into the fire was always risky as the soldered joints could melt again and cause more trouble than initially was the case. The preferable method was to repair a soldered piece without having to expose it again to relatively high temperatures, which is where the soldering lamp comes in. Basically, the soldering lamp resembles a modified oil lamp with an extended snout. To reach temperatures high enough to melt the solder, one had to use a small blowpipe to blow additional air through the flame. Skillful blowing would subsequently result in a second tiny yet feisty blue flame hot enough to locally melt silver. That is, at least, what Van Laer seemed to suggest: “when the tip of the flame of such burning Lamp is blown against the spot that needs to be soldered, it makes it hotter over there and the solder will easily run.”[5]

Figure 2. Engraving of gold- and silversmithing tools. Numbers 7 and 8 indicate the soldering lamp, number 9 the blowpipe. Copy of the Guidebook held by the Rijksmuseum Library, Amsterdam (Call number: 305 E 33). Photo by Thijs Hagendijk.
Figure 2. Engraving of gold- and silversmithing tools. Numbers 7 and 8 indicate the soldering lamp, number 9 the blowpipe. Copy of the Guidebook held by the Rijksmuseum Library, Amsterdam (Call number: 305 E 33). Photo by Thijs Hagendijk.

To find out whether we could indeed solder this way, we decided to build a soldering lamp following Van Laer’s instructions. Luckily, Van Laer was meticulously detailed with respect to the lamp, discussing its dimensions and the materials needed to produce it. According to him, the lamp should be made from brass and should measure 3 inches across and 1 inch in height. Additionally, there should be a wooden handle at its back and at the front a snout of about 5 or 6 inches long. To make sure he was well understood, Van Laer also included a schematic engraving of the lamp (Figure 2). We had more than enough information to work with, and based on his drawings and instructions we produced a much-desired replica of the lamp (Figure 3). We also laid our hands on a few historical blowpipes. Now that we had the materials, we could learn to handle the tool.

Figure 2 (Detail). Engraving of gold- and silversmithing tools. Numbers 7 and 8 indicate the soldering lamp, number 9 the blowpipe. Copy of the Guidebook held by the Rijksmuseum Library, Amsterdam (Call number: 305 E 33). Photo by Thijs Hagendijk.
Figure 2 (Detail). Engraving of gold- and silversmithing tools. Numbers 7 and 8 indicate the soldering lamp, number 9 the blowpipe. Copy of the Guidebook held by the Rijksmuseum Library, Amsterdam (Call number: 305 E 33). Photo by Thijs Hagendijk.

 

Figure 3. Replica of the soldering lamp. Photo by Thijs Hagendijk.
Figure 3. Replica of the soldering lamp. Photo by Thijs Hagendijk.

 

We filled the lamp’s reservoir with olive oil and stuffed its snout with a cotton lump. When we finally lit the lamp, the burning oil filled the room with a scent of grilled food. As an initial exercise, we took a small brass strip and tried to heat it until it started to glow. Here is how it went down, as recorded by Thijs in our fieldnotes:

Glowing the metal strip did not happen before we learned our first big lesson. Intuitively, Tonny and I started out by blowing hard through the blowpipe. The more air, the hotter the flame we thought. After trying for quite some time, it seemed as if we weren’t making any progress. We could steer the yellow flame, but were not able to get the blue flame where we wanted it. Yet, after I tried some more, it suddenly appeared that I had been blowing way too hard. By blowing rather softly on to the flame, suddenly the little blue flame emerged. In general, the blowing required much exercise. When later that afternoon a visitor dropped by for an interview, we saw the amount of skill that we already acquired. She too tried to produce a feisty blue flame by blowing through the flame, but did not succeed. To my own surprise, I was immediately able to point out what went wrong. The tip of the blowpipe should almost touch the pit of the flame, while one should blow out of the flame, both from beneath and from the inside-out. Cheeks filled with air, meanwhile breathing in, breathing out, breathing in, breathing out, filling the cheeks again and keep blowing at the same time. A rhythm occurs in blowing and breathing, which maybe most resembles what happens to your breathing when running.(Fieldnotes Thijs, April 4th, 2017).

Until this point, then, the story was quite successful. We were able to reverse-engineer the soldering lamp, and, like Van Laer explained, we could reproduce the feisty blue flame. Moreover, the blue flame proved rather hot indeed, as indicated by the different oxidation colors on the brass strip. However, as soon as we tried taking it to the next level, we ran into trouble.

Still happy with the progress we made, we now wanted to solder a very basic joint. We took another brass strip, hammered it round, and set out to solder its ends together to make a tiny cylinder. We fixed the cylinder in a standing pair of tweezers to free both our hands so we could steer the soldering lamp and hold the blowpipe. A little piece of solder was put on top of the joint, as well as little bit of borax, which is a flux used to facilitate the flow of melted solder. We lit the lamp and started blowing (Figure 4).

Figure 4. Soldering a brass ring. Note the tiny blue flame. Photo by Thijs Hagendijk.
Figure 4. Soldering a brass ring. Note the tiny blue flame. Photo by Thijs Hagendijk.

One hour later we were so out of breath that we stopped, but the cylinder had not yet been soldered. We failed. Even though we raised the temperature high enough to make the solder curl up like a drop, we never reached the final state in which it flows out and runs into the joint. Using the soldering lamp appeared less straightforward than we thought it would be.

We were curious to know what went wrong, but after several more days of trial-and-error, the list of questions and issues had only grown. We turned to the Guidebook and read and re-read the passages, only to discover that Van Laer was actually quite silent on the matter. Indeed, he carefully described how to assemble the soldering lamp, but spent hardly any time on how to handle it in practice. Should the object be pre-heated, or could the soldering lamp be used on cold objects, too? We blew and soldered against a piece of charcoal to create a reverberating heat source, but was this also how Van Laer meant to use the soldering lamp? Moreover, what type of solder should we use? Van Laer listed three distinct recipes for solder with different melting points, but did not indicate which one to use in combination with the soldering lamp. To date, we still have not been able to solder a proper joint using the lamp.

Interestingly, if we compare the above experiences with other re-enactments we performed, a general pattern starts to emerge.[6] For example, with respect to sand mold casting, Van Laer vividly described how to prepare and process the sand, but left his readers hanging when it came time to assemble a mold from it. Moreover, in his discussion of chasing, he meticulously described how to transfer a design to silver, but gave no guidance on how to perform the actual chasing process. Why would Van Laer alternate between exacting detail and virtual silence? What does this say about the usability of the book? And what could, in fact, be learned from this text?

The soldering story followed a similar pattern. While Van Laer carefully discussed each and every condition needed to succeed – the soldering lamp, recipes to prepare multiple types of solder, different sorts of fluxes – we failed once we arrived at the procedure itself. Is this due to our lack of skill in operating the blowpipe and soldering lamp, or are there aspects of eighteenth-century soldering that we no longer understand? In any case, the Guidebook’s guiding principle seems to be that core operations are best demonstrated rather than put into words. Van Laer did in fact confirm this with respect to the casting procedure. Just as he came to the very heart of the procedure, he abandoned his detailed exposition, stating that “the molding and casting cannot be learned as well as through manual education.”[7]

During our re-enactments, we therefore came to interpret the Guidebook as a text containing advanced practical knowledge, including tips, tricks, and best practices. Learning new skills from scratch, such as soldering, casting, or chasing, is still best done through manual education, but once mastered, the Guidebook can indicate new routes, spell out different paths, and show new variations on a theme.

 

[1] Willem van Laer, Weg-wyzer Voor Aankoomende Goud en Zilversmeden: Verhandelende veele wetenschappen, die Konsten raakende, zeer nut voor alle Jonge Goud en Zilversmeeden (Amsterdam: Fredrik Helm, 1721).

[2] Natasha Glaisyer and Sara Pennell, “Introduction,” in Didactic Literature in England 1500-1800, edited by Natasha Glaisyer, Sara Pennell (London: Ashgate, 2003), 7.

[3] For a more elaborate and contextualized overview of the re-enactments performed on the Guidebook, see Thijs Hagendijk, “Learning a Craft from Books. Historical Re-enactment of Functional Reading in Gold- and Silversmithing,” Nuncius 33, no. 2 (forthcoming Summer 2018).

[4] van Laer, Weg-wyzer, 125.

[5] Ibid, 126.

[6] Hagendijk, “Learning a Craft from Books.”

[7] van Laer, Weg-wyzer, 134.

Blog Series: Learning by the Book

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