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Welcome to
Sundials of the World! USA
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The sundials presented
on this page were designed by Bob Hough of Tucson,
Arizona. One dial was manufactured in part by an
engraving firm and completed by Bob while the other Bob
built himself.
The
following is a short description Bob provided about his
sundials. If you wish to contact Bob send an e-mail to: houghbob@comcast.net
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"I designed
the "Ratz Dial" for a client named Ratz
in Colorado Springs, CO, in 1994. I used my
computer and described the graphic algorithms in
the PostScript language using a simple text
editor. I had to define many new operations that
are not defined in standard PostScript. When
viewed with a PostScript Interpreter, this
renders an image of the dial face that can be
viewed on a computer screen and also printed on a
printer. The angles are adjusted for the
latitude, but the longitude of that site is close
enough to the standard meridian for the time zone
that the longitudinal correction can be ignored.
I converted the PostScript file to an EPS file
with two lines of code and copied it into a
3.5" diskette. I took it to Colorado Laser
Markings, where they read it into their CAD
system and it displayed on the screen (without a
glitch). They drove the engraving machine
directly from the CAD system. Most of their
engraving is laser, but laser doesn't work well
with highly reflective surfaces, like the brass
for my dial, so they used an older, mechanical
engraver. The face is 11" in diameter and
1/4" thick. I hand cut and finished the
style myself from the same 1/4" brass stock
and attached it to the face by drilling and
tapping holes on the underside and drilling and
countersinking aligned holes through the face and
using machine screws and a touch of epoxy between
the pieces. I had the pedestal made from steel
(was going to be wrought iron but my builder had
excess steel). The pedestal is disproportionately
tall to raise the dial face over the top of a
close-by fence so the late afternoon sun could
still hit the face. I mounted the pedestal to a
well seasoned stump with lag bolts and cement.
The brass face has weathered nicely since it was
installed. I had originally designed the
furniture to include an EOT graph on the face,
similar to the dial you did, but my customer did
not like it, so I took it out of the
design." |
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"I
recently did the "Wall Dial" for the
wall along the back of my back yard at my house
here in Tucson. We wanted a primitive "look
and feel" and that is what we achieved. The
wall declines 19.6 deg SW. (I drew a line
perpendicular to the wall on a level board and an
intersecting line along the shadow of a plumbline
and measured the angle. With the date/time to
determine the EOT and sun declination, and the
long/lat, I determined the azimuth of the sun and
thus the wall declination.) To make life simpler,
I used PostScript to calculate for me, instead of
my hand-held calculator. Again, I used PostScript
and not only rendered a basic image of the face
and the style, but also had it print out the
values for the hour angles, sub-style and
style-height. The dial is adjusted for
latitude, longitude and wall declination. The
face is sandstone and the style is 1/2"
copper plumbing pipe with a glass marble epoxied
in the end for appearance. I drilled the hole by
hand and built a wooden form to hold the style in
place while the epoxy set, then removed the form.
The lines are painted by hand (remember, it is
supposed to look crude). A local landscaper
donated the stone (too thin for stepping stone)
and the rest of the materials totaled about
$5. This summer we will see how it holds up
in the desert heat with stone, copper and epoxy
expanding at different rates. From June through
Sept, the probable high is 40 deg C." |
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