Dear
Dialers,
From the BSS
Glossary:
style {stile}: the line in space which generates the shadow edge
used to indicate the time on the dial
plate. Note that a gnomon
with finite thickness will have two styles (one along each of the upper edges)
which will each be operational for parts of every day.
From an email on
this list from Frans W. Maes 8Oct
In my website, I have introduced the term
"nodal dial" for this, as the time is
being read from the shadow of a fixed point
or 'node'. The node may be the tip
of a pin or gnomon of arbitrary
orientation. It may also be a knob on a rod or a
notch in an edge. Sometimes the node is an
aperture in a plate, casting a
spot of light on the dial face.
My question is
- Is there a general term for the part of the dial that
generates first interferance with the sun's rays. For example this term
would apply to all of the following:
- style of a horizontal dial
- rod style of an armillary sphere sundial
- tip of a pin generating a point (node) shadow
- aperture casting a spot of light
- slits generating a line of light (cube dial from this list recently)
- mirror reflecting a point of light on a ceiling
All of the above
does the primary work of generating some line or point (either shadow
or ray of light) that then strikes a secondary dial face.
"Dial Face" seems
adaquate as a general term for the part of the dial that is secondary, but I am
wondering if there is a general term that covers the primary
part?
Thanks
David
