Next message: Richard M. Pisko: "Re: leap seconds a navigational hazard, says expert"
On Sat, 9 Aug 2003 22:52:32 -0700, Brooke Clarke wrote:
>I did not file down the tacks. The heads are a little less than 1/8"
>diameter and were seated so only a tiny fraction of an inch was sticking
>up. You can feel the head with you fingers. No problem to walk on them
>bare foot.
>
That was my first thought; yes. I'm glad it's not a problem, and I
read the description so it seems as though it would be rather nice. I
couldn't quite make out the drawings on your ... calculations, I think
it was.
>>>I made one of these by placing a metal plate at the lower end of a South
>>>facing skylight and using a 3x5 card with a number of concentric
>>>ellipses and a small hole at their center. I just tracked the Sun's
>>>image with the card and at exactly noon stopped and drive a small brad
>>>nail into the hardwood floor. After many years there would be more than
>>>one nail for the same date because as we go through the 4 years of the
>>>leap year cycle the timing is a little different.
>
I see the reasoning behind the series of ellipses on the (much
handled) 3x5 card; to more closely match the sun's shape on the
horizontal floor. What are the rough dimensions of your analem...
figure "8"?
I guess I could calculate that, given the difference in elevation
between the skylight aperture and the floor, as well as your latitude,
but I thought a reality check might be a break from the theory. :-)
--
Richard ...
