A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Rafal O.
Date: 2019 Feb 13, 23:11 -0800
You wrote "I note that, for 11 Nov, you state the declination to be 17°..." Indeed, I made marks every 1' / 1° for EoT and declination. But your comment is right and 2nd version has marks every 0.5' / 0.5°. This should somehow improve accuracy.
"The DSSC also provides the time of meridian passage of the sun on the M scale..." - I think that recreating the original layout of DSSC would be too hard for me from the engineering point of view. Meridian passage can be easily calculated using already known value of EoT and DR longitude. Hence, I decided to skip this part.
"For the DSSC, the circular scale on the base is NOT a complete 24 hours..." - I have already thought about it but have decided to not implement it. I hope that layout of 2nd version would be better then the original DSSC for negative declination for which lines are compressed due to smaller distance from the center. You can see than scales for positive and negative declination on the front face are different. Program that I wrote for making these plates can also calculates civil/nautical/astronomical times for sunset and sunrise. This is also the reason I do not want to changes scales on every version. Of course it can be done but each unit would be slightly different.
"Did you make an actual device?..." - 1st version was made for testing. Screenshots attached to http://fer3.com/arc/m2.aspx/Dunlap-Sunrise-Sunset-Computer-RafalO.-feb-2019-g44299 are from Inkscape. I want to build this version within few days.