| NOCTURNAL DIAL |
Illustrating Time's Shadow the book, focuses on sun dials, and they are based on the sun's altitude, the sun's
azimuth, and the sun's hour angle. An ecliptic dial was introduced, then the lunar dial, and then the star dial,
commonly called a nocturnal.
This is a PDF file of around 200k, four pages, and has a very simple discussion on the nocturnal or star dial.
azimuth, and the sun's hour angle. An ecliptic dial was introduced, then the lunar dial, and then the star dial,
commonly called a nocturnal.
This is a PDF file of around 200k, four pages, and has a very simple discussion on the nocturnal or star dial.
The way that stars are seen, and how they vary nightly
as well as annually is discussed, then how and why a
nocturnal dial is developed, then one is developed for
the northern hemisphere.
Then the method of deciding where to place index
marks is discussed, and finally a template is shown.
Longitude correction is needed, also there may be a
need to apply some sort of an equation of day, and
latitude may come into play also.
Like the lunar and the ecliptic dials, this is intended to
whet the appetite.
But - yes - it does work. In fact it works very well.
as well as annually is discussed, then how and why a
nocturnal dial is developed, then one is developed for
the northern hemisphere.
Then the method of deciding where to place index
marks is discussed, and finally a template is shown.
Longitude correction is needed, also there may be a
need to apply some sort of an equation of day, and
latitude may come into play also.
Like the lunar and the ecliptic dials, this is intended to
whet the appetite.
But - yes - it does work. In fact it works very well.
This dial does not have a hole in the central binding mechanism which is a nut and bolt.
The author allows his eyes to relax and thus merges the Polaris with the nut and bolt.
Which explains my use of 3d stereograms all over the place! Each to their own peculiarities
and obsessions I suppose.
The main dial plate is a computer CD, with the vertical handle glued behind it, and that
solves the problems of using a small thin screw in a CD with a lrage diameter hole.
The hour index is on a piece of plexi as is the star pointer. They are all separated by
washers. Standard PVC glue was used to affix the template parts (in the file you download).
And of course it is important to sight the index star correctly. In the fall in the northern
hemisphere, Casiopeia is easy to use, however a longer cursor may be helpful. It is held up
to the polaris north star, and tilted so the plate parallels the equator, that corrects for some
errors.
Please be careful when using PVC glue, its vapors are not beneficial to the human.
So now, we have the day covered with sundials, half the nights with a lunar dial, and the
balance of the nights with a nocturnal. And that answers the common questions the author
gets at fairs and shows.
Please play with these templates ~ A JPG is included, but the PDF file is best.
The author allows his eyes to relax and thus merges the Polaris with the nut and bolt.
Which explains my use of 3d stereograms all over the place! Each to their own peculiarities
and obsessions I suppose.
The main dial plate is a computer CD, with the vertical handle glued behind it, and that
solves the problems of using a small thin screw in a CD with a lrage diameter hole.
The hour index is on a piece of plexi as is the star pointer. They are all separated by
washers. Standard PVC glue was used to affix the template parts (in the file you download).
And of course it is important to sight the index star correctly. In the fall in the northern
hemisphere, Casiopeia is easy to use, however a longer cursor may be helpful. It is held up
to the polaris north star, and tilted so the plate parallels the equator, that corrects for some
errors.
Please be careful when using PVC glue, its vapors are not beneficial to the human.
So now, we have the day covered with sundials, half the nights with a lunar dial, and the
balance of the nights with a nocturnal. And that answers the common questions the author
gets at fairs and shows.
Please play with these templates ~ A JPG is included, but the PDF file is best.
| pdf template 50k excellent resolution |
| JPG template less resolution |
