{"id":1399,"date":"2011-04-05T14:00:25","date_gmt":"2011-04-05T13:00:25","guid":{"rendered":"http:\/\/s346165667.websitehome.co.uk\/pm\/?p=1397"},"modified":"2015-03-22T10:12:53","modified_gmt":"2015-03-22T10:12:53","slug":"lead-codices-from-jordan-some-notes-on-manufacture","status":"publish","type":"post","link":"https:\/\/userblogs.ganoksin.com\/primitive\/2011\/04\/05\/lead-codices-from-jordan-some-notes-on-manufacture\/","title":{"rendered":"Lead Codices from Jordan: Some notes on manufacture"},"content":{"rendered":"

In the last couple of weeks, a story has emerged about some lead books found in Jordan, which are allegedly ancient. If you want to read critiques of the news coverage, I recommend you to look at these articles on Rogueclassicism<\/a> and History Hunters International<\/a>. I must admit that I retweeted the BBC’s news story. It’s certainly an interesting subject, and very relevant to my work. Frankly, I couldn’t care less if it reveals any earth-shattering religious secrets. I couldn’t care less if it proved that God came from Grimsby, and Jesus just worked on the boats.<\/p>\n

$\"Detail$ <\/p>\n

What is important is the manufacture of these codices. It certainly sounds like they are forgeries, but how well made are they? Are they meant to be copies of something else, or did the manufacturer simply make something that they imagined an ancient artefact would look like. If they are real, then what were the technical requirements needed to make them? I only have a few photos to look at, so this is by no means a thorough examination, and will raise more questions than it answers.<\/p>\n

\u00a0A gallery of pictures can be seen here<\/a>, care of the History Hunters. They are worth a look. This first thing that struck me was that they were all different sizes. Irregular size could simply indicate that the codices are all from a different source, or they could suggest that a single manufacturer was making do with whatever offcuts they had. The basic form of each codex is a number of leaves made from lead, bound with round wire rings, with patterns and symbols in relief.<\/p>\n

\u00a0The simplest thing to talk about is the wire, so I’ll get that out of the way. It looks as if the rings are made from round-section wire, probably in the range of 1mm to 3mm – at those sizes, round wire can easily be made by hammering, particularly in a soft subject like lead. The ability to make these rings occurs at the same time lead can be refined, so they tell us little about the possible date of the books. The rough faceting of the surfaces shows that these are hammered wire, but one tell-tale sign to look at under magnification would be linear striations along the wire, which might indicate a plate-drawn wire that has simply been distressed by hammering, and would be good evidence that it is post-classical (similar striations on the sheet would indicate the use of a rolling mill, rather than a cast or hammer-forged sheet. Rolling mills didn’t exist in the classical period, and neither did draw plates).<\/p>\n

\u00a0The holes for the binding rings look life they have been punched through from the back, and probably reamed out with a soft-edged tool. The flanging around some holes indicates punching – drilling would leave much thinner flanges that would have been easy to remove. The way the holes are raised tells us that the punching was done from the back.<\/p>\n

\u00a0The sheets themselves could be produced in a couple of different ways. They could be hammer-forged, which would leave some toolmarks, but it would require a lot more force to apply the designs on pre-made sheet. That means they are probably cast, perhaps by pouring into an open mould and pressing down to flatten them. Some of the closeups show sheets with a regular thickness, but the shapes of the sheets are often uneven, and sometimes cut through the decoration, indicating that imperfections on the edges of the castings had been removed. Some pictures show what appears to be casting imperfections, but most of the surfaces look smooth and consistent with the slightly granular surface of a casting.<\/p>\n

$\"Edges$ <\/p>\n

As for the decoration: I’ve seen it described as embossed, but in metalworking terms, that isn’t really accurate. If the decoration was embossed, you would see some pages with reverse images, whereas the backs of the pages seem to be plain. In some cases, the fronts have some very high relief shapes (the portraits), which could indicate repouss\u00e9, but as we can’t see the backs of the pages, it’s impossible to know.<\/p>\n

\u00a0If the decoration was added later, there is one technique which could have been used, but doesn’t really fit with the artefacts themselves. This is process called pressblech<\/em>, where the sheet metal is hammered into a die – effectively stamping the designs onto the sheet. This would certainly be easier to do in lead than in other metals, but due to the thin sheets, this would leave some deformation on the back of the lead. It would also require the die to be made from a harder material than the lead, which would be consequently harder to work – if they were skilled in other metals or stone, I would expect the codices to be of a higher standard of manufacturing.<\/p>\n

\u00a0All the features so far suggest that the lead sheets are cast, and if this was done, it would be simple to scrape shapes into the mould beforehand – certainly the quality of the designs would be poor, and that’s what we see when we look at the codices. The symbols look as if they have been done with a blunt stylus – there appears to be no faceting, which you would expect if the designs had been cut into something with a sharp tool. Some of the pages have decoration that is shinier than the background – these are burnished, either with a tool, or by natural rubbing against the page in front (if it was the page in front, you would expect to see some corresponding marks on the back of that page).<\/p>\n

$\"Detail$ <\/p>\n

Aside from shears to cut the imperfect edges off the sheet, we may be looking at work that requires no sharp tools to produce. This could be done in the most basic surroudings, and if sand was used as the casting medium, there would be no physical record left after the works were produced.<\/p>\n

\u00a0I’m not making any conclusions about the age of the codices – I’m not qualified to do so – but I will sum up by pointing out a few limits to this article. I only have photographs, and they aren’t closeups. Many features will be impossible to see without the physical objects or very good closeup images. The metal is weathered, either through age or through human intervention, and this weathering does affect the remaining surface of the metal, potentially obscuring or removing features. In practice, these codices are not heavily corroded, as is seen with many base metals, so the absence of tool marks is surprising – were it a hammered sheet, there would be some visible deformation from the hammer strikes.<\/p>\n

\u00a0If anyone has any more information on the codices, particularly more and better photos, and results of scientific testing, we can probably figure out a lot more about them.<\/p>\n

[Paraphrasing PG Wodehouse, I would like to thank my baby daughter, without whose help this article would have been finished in half the time.]<\/p>\n

\u00a0UPDATE: Daniel O. McClellan<\/a> has a post on his blog which is fairly technical. He also has a list of other articles on the subject<\/p>\n

\u00a0UPDATE 2: After some discussion, I have concerns about whether the thinner sheets could be cast in
\nthe first place. If they were produced in some other way (ie. hammer-forged and stamped) then some heavy chemical errosion has to have taken place, and is probably intentional.<\/p>\n

\u00a0UPDATE 3: Made a couple of minor alterations, softened my wording on the cast vs hammered sheet issue. It’s clear that the best way that a modern practitioner would make these codices would be to make hammer-forged sheet and then produce a metal die into which the sheet is pressed or stamped, but this would only be easy to do on the smallest codices. Another method would be centrifugal casting, which wasn’t available in the pre-modern era.<\/p>\n","protected":false},"excerpt":{"rendered":"

In the last couple of weeks, a story has emerged about some lead books found in Jordan, which are allegedly ancient. If you want to read critiques of the news coverage, I recommend you to look at these articles on Rogueclassicism and History Hunters International. I must admit that I retweeted the BBC’s news story. […]<\/p>\n","protected":false},"author":142,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[6],"tags":[],"_links":{"self":[{"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/posts\/1399"}],"collection":[{"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/users\/142"}],"replies":[{"embeddable":true,"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/comments?post=1399"}],"version-history":[{"count":2,"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/posts\/1399\/revisions"}],"predecessor-version":[{"id":1921,"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/posts\/1399\/revisions\/1921"}],"wp:attachment":[{"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/media?parent=1399"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/categories?post=1399"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/userblogs.ganoksin.com\/primitive\/wp-json\/wp\/v2\/tags?post=1399"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}