Tom Mchugh wrote:
>
> My guess is the the most accurate sort of heliochronometer
> would have optical means of focusing a solar image on an
> analemma (figure 8), and would have optical means of observing
> the sun's image to judge when it is centered on the line.
>
> Time could be conveniently shown on a dial readout, much like an
> analog clock dial, geared to the polar axis of the equinoctial dial.
Hello,
This is my understanding of what is meant by a heliochronometer or
SunClock. I have not seen a conventional horizontal sundial described as
a heliocronometer in the literature I've read.
Russell Porter wrote several articles about various SunClock designs in
SciAm years ago. I recently had the good fortune to obtain an original
Porter SunClock, one of only two known to exist. The URL below leads to
a description about the piece and its operation.
http://www.gcstudio.com/sunclock.html
Regards,
Luke Coletti
