NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Artificial Horizon
From: K Chin
Date: 1996 Nov 19, 19:38 EST
From: K Chin
Date: 1996 Nov 19, 19:38 EST
I would like to add that instead of water in the pan try using used motor oil. Makes a better reflector. This method work quite well for practice, but remember there will always be motion on a boat so if possible practice doing it while you are sailing is best. kp http://www.geocities.com/TheTropics/5471 On Tue, 19 Nov 1996, Jan van Puffelen wrote: > At 20:48 19-11-96 -0800, you wrote: > > >Good evening to you all, since the nav list is a bit quiet can we have a > >small discussion on how to construct a artificial horizon for practice > >sextant work.I know they are commercialy availale to those of you in the > >"civilised world" but not to the likes of us in the wilds of Africa !! > >[lions on every corner, that's why we go to sea ] > >also I seem to remember reading that you don't take eye hight into account > >when using A H is that correct? any other things that are different ? > >regds alistair. > > I have always used a simple open basin/pan etc., filled with ordinary > water. This works well for observations of the sun, the moon, some planets > but only the brightest stars. Apply the full index error of the sextant. > Divide the measured angle by two, do not apply the dip, but do apply > refraction, semidiameter (if any) and Horizontal Parallax (if any). > > The disadvantage of this method is that the maximum altitude is about 60 > degrees (since the angle is doubled). > > Regards, > Jan van Puffelen <puffelej@XXX.XXX> > 52d 24.5'N > 4d 55.0'E > > > > > > > > > > >