Here’s a brief afterthought to yesterday’s posting. There I suggested that a thin layer of sand could have been used to give the Shroud image its fuzzy, ghost-like quality. The sand was to act as a thermal buffer* between a hot bas relief template and linen (see post for details).
* buffer: something that lessens or moderates the impact of something:
Since then it’s occurred to me that not everyone has access to fine sand, especially if one is a medieval monk living a 5 day horse ride from the sea. Is there an alternative to sand, maybe one that has advantages over sand?
Yes, I believe there is – CLAY. It’s finer than sand, obviously, and while still acting as a thermal buffer would help to avoid a speckled scorch that might arise from using sand, even very fine sand. We all know that clay particles are much finer than sand.
But that raises all sorts of interesting possibilities. Clay comes in a variety of colours. There’s china clay, which is white, but most clay is orange or red – due to its iron content. So let’s imagine our medieval craftsman (no need to call him “forger” without knowing his objectives) placing a thin layer of dry powdered clay onto linen, then presses with the hot template. (It’s an experiment I shall try, but I am travelling at present, which is why it’s described here as a ‘thought experiment’). When the template is withdrawn, there is a faint scorch under the clay, with light/dark reversed image of that template (ring any bells?). But what about the clay? Can that simply be shaken or brushed off – assuming its job is done? Or does it not shake off? Are the clay particles bonded to the underlying scorch via pyrolysis products of scorched linen. What if they were, and what if that had been the artisan’s intention? In other words, the desired end product was a thermostencil, with a negative facsimile of the template in reddish clay against the white background of linen. The first cohort of viewers may not have been aware there was a scorch beneath the clay image. Now fast forward some years or decades – and the clay particles gradually drop off, and it’s now just a ghost image that remains, i.e. the underlying scorch… Might not new cohorts, now primed with a revised and more jaw-dropping narrative, have looked at that with greater wonder than the clay original? Might not the originator of the Mark1 artefact have thought, mmm, that technique has possibilities?
From memory, I seem to recall that there’s a lot of aluminium associated with the Shroud linen that has not been satisfactorily accounted for. The most common source of aluminium on the planet is (you guessed it) clay – which comprising the several aluminosilicates of calcium, iron etc. Might it be some adhering clay particles that are responsible for today’s aluminium, being assumed to be adventitious “dust” that has settled on it over the centuries? Maybe not. Maybe clay had a crucial role to play in the initial imprinting of the Shroud image, possibly to portray a man whose mortal remains had been transformed to mineral (“dust unto dust”) aided perhaps by a something that also left a faint underlying scorch (which the curator, adhering to his script, would be keen to point out).
Next topic: Focus on Dr. John Jackson of the Shroud Center of Colorado, his continuing, and, to my way of thinking, inexplicable advocacy of radiation over contact scorching, and his apparent blind spot for heat transfer of the third kind in that strange preoccupation of his with ‘cloth-body distance’.
Here’s a taster (or should that be teaser?):