Dear Shadow Watchers, Since there seems some interest in stab dials I include this comment on an meridianal analemma in that form. If there are others involved in stab/groove/slit dials or that have seen literature regarding them I'd enjoy hearing about it.
Stab Dial - Two - Analemma If one makes a long point roughly a one half degree cone and positions it to minimize the suns shadow then forces it into a surface, the stabbed hole when filled with light will indicate that solar azimuth and elevation. If one makes such stabbed holes in a sphere, just at noon, with the point always pointed toward the spheres center, and at a number of days interval inbetween, at the years end there will be an analemma of stabbed holes. This is a meridianal stabbed analemma dial. Of course, just like shadow dials these holes can be made in any surface and scattered about and still work. In fact several of the same azimuth/elevation holes can be made through a wall to illuminate some figure to celebrate some date and time, or other purpose. -
