NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: leap seconds a navigational hazard, says expert
From: Richard M Pisko
Date: 2003 Aug 10, 20:08 -0600
From: Richard M Pisko
Date: 2003 Aug 10, 20:08 -0600
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 ...