|
From Alan Bowman and David Thomas, Vindolanda: the Latin writing
tablets London: Society for the Promotion of Roman Studies,
1983, pp. 29-31
We must assume that the tablets bearing documentary
texts (Nos. 1-20) originated at Vindolanda, whilst the letters (with
the exception of No. 37) (225)
will have been written elsewhere. It is reasonable to suppose that
the tablets were cut and prepared from timber growing near to where
they were used. In the case of the documents, the tablets on which
they were written were no doubt manufactured at Vindolanda, though
this is impossible to prove and we do know of writing-tablets as
manufactured objects of trade30.
There is evidence for a soldier in Egypt being seconded to the duty
of paper-making, and a passage in the Digest
which lists immunes includes
et qui siluam infindunt31.There
is no doubt that military units must have had the technology to
manufacture leaf tablets. What we do not know is whether any of
the letters at Vindolanda originated outside military circles. The
raw materials, at any rate, were certainly there in antiquity and
both alder and birch still grow alongside Hadrians Wall today.
Large quantities of alder and birch pollen are present in peat deposits dating from the Roman period in this area and indicate that both tree species were common throughout the occupation of Vindolanda by the Romans32. Deforestation was widespread during the latter part of the Roman period in Britain and was mainly associated with an increase in agriculture, indicated by greater prominence of graminaceous pollen and of pollen from arable weeds in peat built up at this time. Some timber would have been used for building purposes. The leaf tablets show that small amounts of timber were used for other purposes and, from examination of the relationship between the cut surfaces and wood anatomy in the tablets, it is possible to outline the way in which they were manufactured.
The tablets would have been extremely supple
when first cut and were capable of being folded across the grain
without breaking. Similar folds parallel to the grain tear easily.
Leaf tablets must therefore have been cut from the outer sapwood
of green timber to obtain the necessary suppleness. The majority
of tablets have to be reconstructed from small fragments retrieved
in the excavation, but Tablet No. 5 (191)
is an almost complete diptych and in Tablet No. 39 (299)
we have the full width of a diptych. The dimensions along the grain
are as follows: in No. 5 (191),
not more than about 16 cm, and in No. 39 (299),
not more than 19 cm (the full width of the complete diptych)33.
Tablets of this size could readily be cut from young trees and the
remnants of bark along one side of No. 5 (191)
suggest that this tablet was taken from a young tree. It has been
cut obliquely through the bark and into sapwood with sharply curved
annual rings. Small knots are also visible in this tablet. Curvature
decreases in older trees with greater diameters and this tablet
has probably been cut from an alder stem of no more than 25 years
growth.
It appears that the largest and most complete
tablets are also the thinnest. Tablets Nos. 5 (191)
and 39 (299)
are not more than 2 mm thick at any point and are, in most places,
just over 1 mm thick. By comparison, many of the smaller tablets
that are very fragmented are about 3 mm thick and are often wedge-shaped,
being thicker along one edge. In some attempts made by Dr. Tapper
to produce similar tablets, it was found that the tablets which
were thinnest and more uniform in their thickness were obtained
from green sapwood, while the only usable tablets cut from drier
wood were thicker and less uniform. When cut these modern examples
were extremely supple and could be folded in the same manner as
those from Vindolanda.
 |
Fig. 5
The manufacture of leaf-tablets in relation
to wood-grain
Image ownership:
© Society for the Promotion of
Roman Studies |
The method of manufacture of the leaf tablets
can be elucidated from the relationship between their cut faces
and features of wood anatomy. The tablets are rectangular, with
shorter sides which cut across the wood to reveal vessels in transverse
section. The longer sides are aligned with the grain of the wood
and the tablets must therefore have been cut in a plane roughly
parallel to the main axis of the tree. The long edges of the tablets
are oblique rather than square in relation to the writing surface.
Longitudinal sections of these oblique edges all give side views
of the medullary rays (PL. XIV - launch Plates viewer window). These sections
therefore lie in the radial longitudinal plane. It is probable that
the wood has split along this plane at the edges of the tablets
during their period of burial, and perhaps even before they were
discarded.
Cross-sections of the medullary rays were obtained at right-angles to the radial longitudinal plane on sections taken from the tangential plane. As illustrated in FIG. 5, the plane in which cross-sections are observable lies at an angle to the flat writing surface rather than parallel to it. This indicates that the tablets must have been cut across the wood, passing through a series of annual growth-rings in a broad plane set at right-angles to the radius of the trunk.
The information from these observations is consistent with the tablets being cut from the sapwood of young trees, possibly with the use of a spokeshave or a very sharp knife with a long blade. The use of the plane seems to be ruled out, in some cases by the thickness of the leaf, but in most cases by the dimension across the grain, which is normally greater than the breadth of the plane blade34. Given the popularity of veneered furniture, the variety of wood used for veneering and the high degree of expertise achieved in cutting veneers35, we are tempted to make our analogy in this area but we have not been able to find any precise evidence for how veneers were cut. The connection, at least, seems to be supported by one statement of Pliny the Elder, even though its meaning is obscure and textual corruption is suspected: nunc intra pugillares lectorumque silicios ??? [aut lamnas] raro usu spectatur (NH 16.68, on the use of maple)36.
The thinnest and most complete tablets may have been prepared from selected timber, but the thicker tablets may well have been produced from any timber available. Possibly they were a by-product formed during the initial trimming of trunks and boughs for other uses and all these leaf tablets could have been produced locally, as they were required.
By contrast, the two stylus tablets examined by Dr. Turner are made from larch or spruce, neither of which is native to Britain. These tablets must therefore have been manufactured elsewhere in the Roman Empire and imported into Britain.
The ink presents no obvious problem. We assumed from the
outset that it is likely to be the normal mixture of carbon black,
gum and water which is found on papyri (iron-gall ink did not come
into use until a later period)37.
The sensitivity of the ink to infra-red rays seems to bear this
out. Again, there can be no doubt that this could be made up as
and when needed, though it was easy enough to transport it or send
it in blocks which could be moistened by the addition of water38.
|
