NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Old Sextant on German money
From: Alexandre Eremenko
Date: 2007 Mar 9, 14:15 -0500
From: Alexandre Eremenko
Date: 2007 Mar 9, 14:15 -0500
Dear George, It is nice to hear (read:-) from you again, I was already beginning to worry, where did you disappear from the list:-) I will reply your very interesting message separately, but now let me recall that I am planning a trip to England for two months (June-July) and it will be very nice if you send me your address and telephone number so that we schedule a meeting. Certainly you do not have to post this private info on the list: my e-mail is eremenko@math.purdue.edu Hope to see you this summer, Alex P.S. Just for the case you missed it: I finally bought a vernier sextant. This is a C. Plath pentant, with all classical features: 7 1/2 inches arc, divided on silver to 10", with a reading microscope, and light diffusor, fully adjustable telescope fork (collimation and transversal displacement,) 3 telescopes (approx. 12x inverting, 6x straight, and 3x night scope) plus a zero-magnification tube and a dark eyepiece filter for checking IC from Sun. Everything is in working condition, the arm moves very smoothly, though I had to clean it a lot, and to adjust. I cleaned the arc (which was so dirty that it was impossible to read) with oil. Just put some oil and wipe it hard with paper napkin. Now it shines:-) I disassembled, oiled and cleaned the vernier assembly and the horizon mirror assembly with the adjusting screws. Now the arc is readable, only have some dark oxidation spots in some places. I had no chance to make many observations yet, except the IC and some star distances. Short distances were fine, but the long ones not. I still have to adjust the collimation. Unfortunately, the wires in the inverting scope I broken and I had to remove them. (I saw this on many old sextants). Apparently people just push something inside to clean the lenses, and do not notice these wires which are much thinner than ordinary hair. I suppose that in the future I will try to find very thin wire and glue the wires into the scope, though this is a VERY high precision operation. At least for me:-) Alex. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---