NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Daytime Venus Rising Dip Short
From: Robert Eno
Date: 2012 May 6, 10:52 -0400
From: Robert Eno
Date: 2012 May 6, 10:52 -0400
From what I understand, two vertical wires are all that is needed because with a spherical bubble chamber, a slight fore and aft tilting of the sextant has no appreciable effect on the accuracy of the sight. A lateral (side to side) tilt does have significant negative consequences in the accuracy of the sight. I can support this contention based on my own observations taken with my MkIXA sextants and with the pre-1970's era C.Plath bubble attachment (notwithstanding that the C.Plath has both vertical and horizontal wire). I have had the pleasure of using a Kollsman Periscopic sextant in a C-130. Let's just say it is not as easy as it looks! Robert ----- Original Message ----- From: "Alexandre E Eremenko"To: Sent: Sunday, May 06, 2012 10:08 AM Subject: [NavList] Re: Daytime Venus Rising Dip Short > > Gary, > >> They are only in the Kollsman instruments. > > In MkIXA as well. Two vertical wires helping you to keep the > bubble near the center. > > > Alex. > > > > > __________ Information from ESET Smart Security, version of virus > signature database 7113 (20120505) __________ > > The message was checked by ESET Smart Security. > > http://www.eset.com > > > __________ Information from ESET Smart Security, version of virus signature database 7113 (20120505) __________ The message was checked by ESET Smart Security. http://www.eset.com