lets establish what we are arguing over.
Vase 1 “Beehive”:
vase 2
Vase 3 “Spinner”:
Vase 5 “Ultra Thin”:
This supplemental study is a hands-on approach to stone vessel
analysis in an applied setting and intended to be more easily under-
stood by readers without a background in engineering or metrolo-
gy.
Each vessel was selected due to its granite composition and high-
precision craftsmanship. Structured Light scanning and CT (X-ray)
scanning have also been performed on each object, allowing for
rigorous, precise, and repeatable analysis.
The plate layout inspection is performed on standard rotary table
(“rotab”) attached to a granite surface plate, which when rotated
revealed <= 0.001 inch runout on the outer diameter and <= 0.001
runout on the top surface.
A perpendicular line coaxial with the center of rotation is defined
as the Z axis. Depending on the object's geometry, three (3) or
four (4) individual points along the Z axis of the body of the vessel
are selected to locate the tips of each dial indicator (figure 1) held
securely in height stands (figure 2). The tips are deflected and test-
ed to ensure that they have free +/- movement. The distance from
the tip to the top surface of the rotab is measured and recorded.
The surface variance between lug handles is also measured as this
continuity is of primary interest.
Concentricity, Roundness and continuity are measured as the
rotab turns 360 degrees, allowing each mounted dial indicator to
measure surface deviations down to less than one half thousandth
(0.0005) of an inch. The surface variance between lug handles,
which interrupt the continuity, is also measured as the continuity
is of primary interest.
Where possible, the wall thickness is measured with Dyer Dial
thickness gages placed at four (4) approximate equidistant points
around Area C. (see figure 3)
A control variable is also introduced: a black and white marble
vase manufactured in the mid 1990s using modern lathe machin-
ery. Notably, no modern machined vessels with lug handles could
be located. Though marble is considerably softer than granite, we
encourage readers to acknowledge the precision in construction
as it relates to the ancient granite vessels that have traditionally
been considered to be entirely hand-made
