NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Instrument repair
From: Paul Hirose
Date: 2002 Dec 18, 20:32 -0800
From: Paul Hirose
Date: 2002 Dec 18, 20:32 -0800
Ken Gebhart wrote: > > lower lenses of the chamber. This is predicated on the fluid in the chamber being > xylene, which it is in all aircraft sextants except the Kollsman periscopic > sextant which has a silicone fluid, as does the C. Plath marine bubble chambers. > We have not heard of a recommended size for these. Thanks for a highly informative message; I archived it on my computer. A copy of the Kollsman manual came with my sextant. It says, "Suggested size of bubble is about 1 1/2 to 2 degrees (the sun appears to subtend about one degree)." At first I thought the manual was wrong about the sun's size, but then I realized it must be including the sextant's 2x magnification. I don't know why the writer didn't simply say to make the bubble about 1.5 to 2 times the diameter of the sun or full moon.
