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Hi David,
Terminology in gnomonics is a difficult problem.
It depends on the language you use and how some
words have changed their meaning in that language.
As you may see in my program zw2000, definitions, I
use the words
- gnomon
- style ( often also polar style )
- substyle
and the whole we name a style-triangle. (direct
translation from Dutch into English)
In English nowadays gnomon is used for the
style-triangle.
Gnomon is a rod or edge, even imaginary,
perpendicular to the dial plate of which only the endpoint in used as a
node.
A style is a rod or edge parallel to the earth
axis.
Sybstyle is the line on the dialplate perpendicular
beneath the style.
A node may be a solid to give a point of shadow,
but also a hole in a plate to give a spot of light.
A style also may be a solid to produce a line of
shadow or a slit to produce a line of light.
See also in the book by Cousins about this
subject.
Best wishes, Fer.
----- Original Message -----
Sent: Saturday, November 10, 2001 1:14
PM
Subject: Style terminology
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
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