A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Herbert Prinz
Date: 2017 Nov 2, 02:10 -0700
Not meaning to spoil the fun at the live session, but since you posted your questions here instead of sending it to the dedicated e-mail, I will give here a preliminary answer to #2.
The sferoscopio del Pino is the italian version of our beloved Rude Starfinder 2102-D. Basically, it provides the coordinate transformation from Alt/Az to RA/Dec, GHA/Dec, and LHA/Dec or back by means of a stereographic projection. Since it comes with 30 doublesided latitude inserts, providing 60 latitudes from 0 to 58; as well as separate overlay disks for each celestial hemisphere; it is accordingly more accurate than the American version. But to what avail? To find or identify a Star, the lesser accuracy of the Rude 2102-D is perfectly sufficient for those who need such a tool at all; while even the sferoscopio del Pino does, of course, not provide sufficient resolution to replace a numerical sight reduction. But the sferoscopio can also be used for sailing the orthodrome and one would have to try one out to see whether the attainable precision compares to the one of manual compass stearing.
I do not see what you mean by "sighting of celestial bodies". The sferoscopio is not an observation instrument. It is an analog computer.