> Side note: I've always been too scared to offer my customers declining
> and or reclining sundials, unless they are local and I can personally
> visit the site. Not because I don't know how to design them, but
> because I cannot trust the customers to measure a wall's declination
> and inclination correctly. Even for an experienced dialist and
> surveyor, this is a challenge. I can just hear the customer
> complaining to you that his expensive new sundial doesn't work
> (because he took the measurements wrong). I wish we could come up
> with an easy fool-proof method that an ignorant non-dialing customer
> could use to determine a wall's declination. I wonder if you and the
> customer could trust a hired surveying company of some sort to measure
> the window's declination?
I could envision a packaged "device" you could mail to the customer, wiht
instructions. It would be placed against the outside of the window (or
wall) in question, when the sun falls fully upon it. You would have a
plane surface with a straight edge held against the window, a pin,
perpendicular to the plane, near its far edge, a circular bubble level,
and an inexpensive LCD digital watch. Held on a bar of some sort above the
surface would be a disposable 35mm camera. The user places it against the
window, adjusts until the bubble is centered, and trips the shutter. You
receive the whole package, folded back up, and process the film. The pin's
shadow is seen on a grid printed on the surface, along with the date and
time (set, say, for GMT) of the measurement. With this, you would also
need a protractor arm of some sort, also in the camera's field of view,
that is unfolded to lay flush against the window, at the same time.
An alternate form might be to have the "protractor arm" perpendicular to
the plane, also, and a linear bubble level, exactly parallel to the
"back" edge, for levelling on one axis only. The user takes TWO pictures,
some days apart, and again, you do the math from the shadow images.
Dave
37.28N
121.97W
Hmm... "The above instrument description is free for use, but not
manufacture for commercial purposes". Just in case!! :{)
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