[Regia-NA] Circles and dots

[rmhowe]

Tracie Brown wrote:
> Looking through Halvgrimr's pages 
> 
> http://www.missouri.edu/~winsloww/archives/gamepieces/Vik_Art/
> 93.jpg
> 
> has inspired me to ask:  Does anyone know of a period 
> implement or method, conjecturally period implement or 
> method, or even a modern way to mass-produce these ubiquitous 
> circle-and-dot motifs? (Some other way than wood-burning,

In the case of bone a massive amount of heat will crack or
craze it. The Chinese habit of divination by touching
scapulas with hot irons and reading the cracks would be
a good example of why not to burn bone. Of course when there
are over 40,000 Chinese characters in the old language in
multiple script styles you can find all sorts of things in
widely varying cracks.

 > I might add.) The best I've done is to file a screwdriver into
> an inverted U, which works but is hell on my hands.

That's creative. Remember that the cutting edge must
be tangential to the center and it will cut better.
Any raised grain can be sanded off. Bone scribes just
fine, antler will be a bit more grainy.

> BTW, I have an interesting story regarding these.  I sent a 
> similar query to a specialty tool and bit company, hoping I 
> might find something modern to do the trick, and included a 
> different picture of some 11c dice.  The guy I corresponded 
> with didn't read my message carefully and thought that they 
> were of modern manufacture. He allowed as how they could only 
> be done with some sophisticated manufacturing process and 
> tools.  He was quite amazed and impressed when I pointed out 
> that they had been made 1000 years ago with hand tools. 

The Japanese have a brad awl/boring tool that has triple
points on the end of the shaft with the central one longer.
The upper handle decreases in taper towards the back end and
is rotated between one's palms. This -might- reproduce similar
marks with much duller points, but what if it skipped? I am
not familiar with such marks on bone or antler combs from
skipping. The ones I have examined seemed to have rounded
holes and rings in cross section.

It would be quite possible to make a ring and dot motif
drill point by reworking a -woodworking- drill point, the
kind that has the edged cutters on the outside edge by
refiling them. For small things I think I'd mount it in
a pin vise with a rotatable head. [When I took silver
cloissone I took a steel needle in a pin vise and ground
the head off and left the eye depth just long enough to
hold the flat silver wire. Works wonderfully for tiny
bends in annealed .999 silver. My class teacher was
amazed at it and had me make some for her [she does it
professionally]. Similarly I made a leaf shaped pair of
needle-nose pliers to bend laurel leaves with a central
stem in one piece. The taper down the jaws allowed for
different sizes.]

> 
> -- Signy

I think many of them were simply cut out with a pair of dividers.

One could also do this with brads at different distances
that are cut and filed in a dowel end, or a wire bent
and tied tightly into a slot in a dowel end.

One point of which was somewhat round and served as the
center, and the other point of which was ground/filed
halfway through to make a scraper/cutting point.
One would use the cutting point to make the center hole
first by twisting it and then cut the outside ring.
Looking at it in vertical cross-section it would be a D
shape tangent to the center point so it could scrape.

In the case of at least one comb I've looked at the use
of dividers for layout and engraving had to have been done
with dividers because the surface had large arcs on it
and the surface was also so uneven that a normally
rotating tool wouldn't have done it successfully.
A hand tool with patience could.

Besides which it has been clearly proven that dividers
or a very similar cutter was used to replicate the
Trig Lane spectacles [I have two detailed articles on this.]

One should also remember that most craftsmen were probably
illiterate and had a tremendous variety of measuring
methods - but all but the crudist would know of using
dividers to subdivide distances - something I used many
times in my own woodworking and furniture making career.
One class I have never resented taking was Geometry.
I collect antique dividers and calipers out to 40"
- some of which are probably well over 200 years old.

Of course you see the same motifs in metalwork sometimes
in which case it would most probably have been punched in.
If I were to make the punch for that I would probably
have an original O shaped punch made by center punching
the end of a flat ended red-hot punch with a center punch
and using that to file down to get to the O shape, then
hardening it and using it again to get another negative
punch shape and center punching that to arrive at a
punch with a hole in the center of the O. This then would
be used to punch the ring and dot motif into metal.
Lacking lead/pitch as a backup metal I would be inclined to
use the soft end grain of a somewhat recent stump or log.
When I used to punch my maker's mark into furniture the
end grain always took the letters quite well.

One should also remember that the Celts used very complicated
arcs on their mirror series [more so than the Roman mirrors
I have seen]. Doing that work without dividers would be
next to impossible. Very complicated layout schemes have
been demonstrated for them.

Magnus