Sunday, September 20, 2015

Some Interesting Gleanings from "Theophilus"; Part I

A couple weeks ago, in the course of preparing different materials for my box, I picked up my copy of Theophilus to re-acquaint myself with possible medieval methods of faceting and polishing gems. I will be using some semi-precious stones as part of the box decoration, and was trying to think of how they might have been ground and polished in the early Middle Ages. I was right in remembering that he had written on that topic, but wound up reading the entire book again in the process.

At the beginning of the book, in his prologue, Theophilus makes mention of Germany producing "fine work" in many mediums, including "wood" Unfortunately, he does not elabourate on this, but there are a few very finely wrought, surviving wooden artifacts, both sculptural and furniture, which come from Medieval Germany. (Of course the same can be said of Italy, France, Spain, England and the North Countries.)

I have already mentioned, here, his writing about gluing up panels, which also includes the mention of planes; a couple of points of great interest to anyone such as myself, who is both a furniture maker and a student of Medieval History. As I went through the book, I began underlining all the passages that spoke of furniture and furnishings, and methods of applying ornament to those objects. In this blog I will share many of those passages with you; as well as a few of my own thoughts inspired by them,

12th century altar panel in the Vatican Museum
This panel was joined as described by Theophilus in his
De Diversis Atibus. The green arrows point to cracks
in the joins between the individual timbers which make
up the panel as a unit. Notice that not all the joins have
failed, however.

For me, the largest 'nugget' of information is the just-mentioned text about panels, planing, and glue. The book I have, was written/translated by John G. Hawthorn, and Cyril Stanley Smith in 1963 (available from Dover, in the States), but I have also read a couple on-line translations, looking for variations in the text. The on-line version I like best can be found here, I like it, because it has the Latin text to compare the English translation with. This version was written/translated by R Hendrie, in 1847. (the first "modern" version of this work was translated in the late 18th century; it has been a work of interest to historians for a long time.)

I do not want to get into the weeds of technical details of the book, and the issues of dating or authorship, all of which are highly subjective, and disputed, but the core text, as it has been preserved to our day, comes from a couple of mid 12th century copies of the work, as well as a few later copies bound with additional texts from other sources.

I will copy here, the version from my book, because it is the easiest to read, whilst trying to type this. The first part I will share is the much mentioned bit about gluing up panels;

"Chapter 17"

"The individual pieces for altar and door panels are first carefully fitted together with the shaping tool that is used by carpenters and vat-makers. Then they should be stuck together with cheese glue which is made in this way;
       "Cut soft cheese into small pieces and wash it in hot water, in a mortar, with a pestle, repeatedly washing it with water until it comes out clear. Thin the cheese by hand and put it in cold water until it becomes hard. Then it should be rubbed into very small pieces on a smooth wooden board with another piece of wood, and put back into the mortar and pounded carefully with the pestle, and water mixed with quick lime should be added until it becomes as thick as lees. When panels have been glued together with this glue, they stick together so well when they are dry that they cannot be separated by dampness or heat. Afterwards they should be smoothed with an iron planing tool which is curved and sharp on the inside and has two handles so that it can be drawn by hand. Panels, doors, and shields are shaved with this until they become perfectly smooth. Then the panels should be covered with the hide of a horse or an ass or a cow which should have been soaked in water. As soon as the hairs have been scraped off, a little of the water should be wrung out and the hide while still damp should be laid on the panel with the cheese glue."

There is a lot of information in this short bit, but what is interesting to me is the mention of "the iron planing tool" The authors of the version of the book I have, are letting their pre-conceived prejudices about medieval technology get in the way of their translating and put in bracket "i.e., a drawknife" but they obviously  do not know much about planing and joining, or how nearly impossible it would be to join up timbers with a drawknife, nor do they seem to be aware of existing medieval planes and plane illustrations which show that the planes often had two handles. (You can read St Thomas Blog, for a lot more information on medieval planes if you like.)

An early medieval/late antiquity plane made of ivory and iron

It is also worth noting that in order for timbers to be glued together in such a way as to stay glued, they must be absolutely uniformly mated together, as in, no gap between them. The only way to practically achieve this is with a plane. Notice in the first illustration of this post, a 900 year old panel which still has many of its glue joins intact.

Another interesting bit about planing timber can be inferred from a passage in section three, chapter 2, where he is giving instructions on setting up a goldsmith's workshop. Speaking about the workbenches, he states; "The table should be so flat and smooth that any little shavings of gold or silver that fall onto it can be carefully swept up" This sounds like a very different surface from what most people have in their minds when it comes to medieval tables. I even venture to be bold enough to say that these tables would need to either be waxed or varnished, because no matter how smooth they were planed, without a sealer, they would still trap gold filings.

Theophilus actually has a chapter specifically about making exactly that, varnish and coloured varnish, and especially mentions "making doors red" with this oil varnish. Mick Jagger could have even seen his red door in the 12th century apparently.

In later chapters of the first section, following those related to making the glue, (both cheese and hide) he speaks more about gluing and using hide or cloth to cover the timber before adding paint. In Chapter 22 he states that "Horse saddles and eight man carrying chairs, that is , curtained seats, and footstools and other objects which are carved and cannot be covered with leather or cloth", should still be covered with gesso before painting.

An interesting bit that I did not catch in the first couple of reads of this book, was a chapter on making paint with the resin of the "cherry or plum tree". I wonder how that works out? I have not heard of anyone using this method.

Still on the topic of paint, chapter 26 states;

"On wood, you should apply all pigment, whether ground with oil or with gum resin,[the just mentioned fruit-tree resin] three times. When the painting is finished and dried, carry the work into the sun and carefully coat it with the gluten varnish. [oil varnish mentioned above] When the heat begins to make it flow, rub it lightly with your hands. Do this three times, and then leave it until it is thoroughly dried out."

This brings to my mind, images of bright, gaily coloured, glossy painted panels, not the worn out battered bits of objects left to us in museums. As I have said many times before, medieval society loved vibrantly coloured and decorated objects. There are yet more snippets of information in this book to confirm that notion as well.

The third section of this book is the longest and most detailed, and is primarily concerned with the various arts of metalworking. Because of this, many historians believe Theopholis to have been a goldsmith himself. In chapter 72, he is writing about making copper foil and the things that can be done with it, such as punched work, openwork, and other types of sheet-metal decoration, both gilded and silver plate. he then says; 

"Copper plates are also made and engraved and coated with black and scraped. these are then put in a pan containing molten tin so that the scraped places become white, [silver] as if they had been silvered. Painted chairs, stools, and beds are bound with these plates and books of the poor are also ornamented with them."

This passage, to me, is nearly as exciting as the one about glued up panels. Here, he is making a distinction of less costly furniture, but it still obviously quite highly ornamented. He specifies "painted" furniture, to distinguish it from other types, unfortunately, we do not have any full record of what other types there might be, but they would obviously include furniture which was completely covered in, or even made of, gold and/or silver, furniture which was covered with ivory, and dare we think, perhaps, even furniture which was finished with "the gluten called varnish"? He does have a passage in chapter 75 which includes the mention of "precious wood" presumably this would be wood which had a beauty thought highly enough of, to not paint it or cover it with gilt foils.

It is also interesting that he states this type of work being applied to things related to "the poor" perhaps this is a relative term, but he uses it again in another chapter, this time on making foil of gold and silver soldered together. "This work has the appearance of silver that has been gilded on one side... Borders are made out of this sheet and are impressed with a die... Narrow strips are cut from this sheet and they are twisted around silk in spinning. Gold fringes are woven from them in the homes of the poor just as among the rich they are woven of pure gold."

Wow, that sound to me just like the drab grey or brown woolen clothing that is all too often seen in modern "medieval reenactment" scenes! 

Yet another passage of class distinction comes from chapter 92;

"When you have made spurs, bits, and saddle furniture for humble clerics and monks and have filed them smooth, heat them a little and rub them with the horn of an ox, or with goose feathers. For when these are slightly melted with the heat and stick to the iron, they will provide a black colour which is somewhat appropriate for them."

In contrast to this statement is the passage in chapter 78 on gilded or silvered repousse' work;

"Now gild the plates and polish them first with brass wire brushes as above, and then with burnishing tools. Colour it [gold requires some sort of treatment after being heated, to actually give it the 'gold' colour we know], fasten the gold settings, each one in its place, and insert the gems, and fasten the pearls round them. In the same way you can, if your inventory allows, make gold and silver on the books of the gospels and on missals; also animals, small birds, and flowers  [This is a distinction from the saints and angels of which he had been speaking of for the ornament of ecclesiastical furnishings.] on the outside of the riding saddles of matrons."

The last little tantalising allusion to opulence, insofar as furniture is concerned, comes from chapter 95; a short bit on working ivory. 

"Now fashion ivory handles, round or ribbed, and make a hole down the axis, Enlarge the hole with various appropriate files so that the inside is the same shape as the outside and the ivory is even throughout and moderately thin. Around the outside delicately draw little flowers or animals or birds or dragons linked by their necks and tails, pierce the grounds with fine tools and carve with the best and finest workmanship that you can. After doing this, fill the hole inside with a piece of oak covered with gilded copper foil so that the gold can be seen through all the grounds. Then seal up the hole with pieces of the same cunningly that no one can see how the gold was inserted."

Unfortunately, he does not go into any detail about what one is meant to do with these "handles", but I like to think perhaps they belong on the doors of cupboards and desks.

A 12th century French capital showing a cabinet
Though this cupboard has no doors, it is likely depicted that way for
technical reasons, and to more easily show the contents of the interior.

In all, this is a fascinating book, and there is much more to be gleaned from it than I have time to share now, but I hope you have found these bits as enlightening and informative as well. As I have said before, the "Dark Ages" were dark because no one bothered to put the lights on; that is what I am trying to do, one blog entry at a time, however.

Videre Scire


  1. You refer at the beginning to " medieval methods of faceting and polishing gems." I remember Theophilus discussing polishing but I didn't think he ever mentioned faceting. There are some early stones with flat surfaces on them, although the elaborate geometrical facet cuts are late or post period, so he could have, but I didn't think he did.

  2. Thanks for your comments and your thoughts. I plan to address this very topic in a blog posting when I get to the stage of doing the stones for the box, so I will not go into great detail here. You are in the same camp as most other people in thinking that gems were only polished in their natural form before the 14th century. Faceting is perhaps a term subject to interpretation, but in my mind, a square stone with a chamfered edge or a round one with a flat top and a bevel are both faceted, though perhaps not as people think of the term now. If you examine most any early medieval work which has its original jewels intact, you will see both of these types of treatments to stones. You will also find a few with even more elabourate designs as well as others which have figures cut into them.Also, stones (rubies and garnet for example) that are perfectly round and smooth, are not found that way naturally and thus were shaped by artistic effort. You are correct in stating that Theophilus does not mention "faceting" gems, but he does tell how to cut them. There is also another clue to the fact that there was more than simply polishing going on, but I will save that gem for the blog.

  3. Hi Johann,

    I actually have made and used this medieval cheese glue myself (made from French brie) and it holds amazingly.

    For the ivory handles on furniture you mention, this could also be the end of the folding x-chairs, like the faldistorium from the Nonnberger Benediktinerinnenstift where the end are ivory carved dragon heads.

    Greetings Marijn /Thomasguild