priddy on thu 1 jun 00
you aren't accounting for the micro-magnetism generated by the spinning
and the water's polarity. It can make things "line up" in non mechanical=
ways, on a chemical level, far deeper than your thumb...polarization and
magnetism may be your missing link in gettin this concept.
On a molecular level, it is a significant force.
EP, ala big-science brained husband again, he still could be wrong...but =
I think he has one here.
iandol wrote:
> Subject: s-shaped cracks update
> =
> I suppose every one who throws clay for a prolonged period will at some=
=3D
> time or other run into the problem of S-cracks. Perhaps Rhonda Oldland =
=3D
> would give more information about the clay primer from which she quotes=
=3D
> to describe a way of tensioning the base of a pot. The term Tension is =
a =3D
> change from Compress. I know about the technique she describes but have=
=3D
> always found that when I apply the sort of pressure which I discern is =
=3D
> needed I finish up with my finger or thumb going through the clay to th=
e =3D
> wheelhead if I move from the centre to the inner base of the wall.=3D20=
> =
> There is another thing which continues to concern me. It is description=
s =3D
> of the way clay particles align themselves as parallel sheets in =3D
> response to pressure. Although there are idealised diagrams in several =
=3D
> books which show this, not one author has come forward with =3D
> photomicrographs of unfired pots which clearly illustrate that this =3D=
> happens as a fact. Therefore I tend to consider their information to be=
=3D
> assumption, conjecture or imaginative.
> =
> Like Rhonda, I have an open mind on the matter, until better evidence i=
s =3D
> presented. But having said that, I find it difficult to accept that =3D=
> platelets of clay in any clay body (which may have more than forty =3D
> percent non plastics whose particle size is two or three orders of =3D
> magnitude greater, that is a hundred to one thousand times the size of =
=3D
> clay particles) are going to respond to pressure from a thumb which has=
=3D
> an area a million times larger that that of the majority of clay =3D
> crystals.
> =
> Should anyone wish to take this discussion further I would be pleased =3D=
> hear what they have to say.
> =
> Ivor Lewis. Often doing things in a contrary way to gain understanding.=
> =
>
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respectfully submitted,
elizabeth priddy
priddy-clay@usa.net
http:www.angelfire.com/nc/clayworkshop
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