Sun dial

[Janne]

Maybe not so bushcrafty, but outdoorsy at least. I have been thinking of making myself a sun dial.
Two in fact, one for here in Cayman, and one for the arctic location of my Norwegian ‘retreat’.

For the one for here in Cayman, I thought to use a piece of Cararra marble slab for the disc and home cast Pewter for the ‘hour hand’. Needs to be able to withstand the sun, heat, salt and termites.
For the Norway one, a wood dial ( lighter than stone to transport) and a hand made from bone ( thinking maybe carved cow bone )
Due to the cold stuff rot really slowly.
Has anybody made one?
Ideas?
I was toying with making the Norway one with some kind of Norse inspiration, both for the woiden dial as the hand.

 

[Robson Valley]

I've made a bunch of sundials.
Ascending, descending, flat ( the pointer is called the 'gnomon'), wire and spherical (the coolest.)
How accurate do you want this? You need the annalemma of time carved as a solid.
The geometry of the hour plate is very clever, you will enjoy learning about that.
If I made a flat one for my house, I'd set the gnomon up at 53 degrees and pointed at Polaris, the pole star.

Without any doubt at all, the best designs and the best theory and constructions are all 100% British.

 

[Tengu]

The Art of Sundial Construction, by Peter Drinkwater.

I have one of his dials too, a portable one.

 

[Janne]

I will see if I can find some online construction info.
It can not be so difficult, it has been done for millennia, right?

Of course, I want it to work correctly, as I will be putting in a bunch of hours.

Last night I realized that a cow bone gnomon is not feasible, but a sheeps bone is.
Cow bone here is all cut up, but a large Leg of lamb has it intact!

 

[Robson Valley]

Lee Valley has a book and several sundials for sale.
I have the LV Aquitaine Sundial ring (LV # KD201) which is a marvelous bit of British royal history as well.

http://www.leevalley.com/

 

[Janne]

Does it work? +- what?

I have always been deeply fascinated by time keeping. Hence my second collecting hobby, collecting watches.

I have a quite good ( if I may say so myself) collection of watches, most were responsible of accurate touristing of the London sky during WW2.

 

[Robson Valley]

Oh, but it does. Hung on the cord, there's a hole in the ring allowing a spot of light to fall on the hour lines.
I guess she needed to know when to play hookey to get a little nookie before hubby got home.

Balsa wood prototypes were easiest to build from the books with a razor blade and a hot glue gun.
Pieces of coat-hanger wire, junk like that.

One of the real joys of retirement = 30 minute accuracy is great.

 

[Janne]

30 minutes is not bad from a ring. I guess 10 -15 minutes from a larger sun dial?

So that ring is a Paleo Tinder of a sort?

 

[Robson Valley]

Balboa Park is the great big zoo place in SanDiego, California. Screen bird houses and all.
Just inside the upper entrance is an equatorial sundial, about 8' in diameter.
The carved annalemma of time casts the shadow on the hour ring so it compensates for Earth's elliptical orbit.
Accurate to 2 minutes.

30 minutes is my time scale. The Aquitaine Ring is good to about 15 minutes.