NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Artificial horizon question
From: George Huxtable
Date: 2009 Apr 20, 12:09 +0100
From: George Huxtable
Date: 2009 Apr 20, 12:09 +0100
Peter Hakel asked ...... And to take it one notch further, how about an artificial horizon for the stars and planets (at night, of course)? Are there any systematic methods to ensure that the star reflected on the surface is indeed the one I intend to observe? ============= For stars at night, there's no good substitute for a pool of Mercury. And with an artificial horizon, your use of stars is no longer restricted to twilight, so you can wait until the sky gets really dark before you take a round of star-sights. But if other fluids such as water are used as reflector, the sky here in the UK seldom gets clear and dark enough for stars to be seen clearly.. However, the archives of this list (or, more likely, its predecessor, nav-l) should contain postings by Kieran Kelly, who enlivened our pages for a time by postings of his overland navigation, by horse and by camel, in the Australian outback. He described the navigation in the desert of Augustus Gregory, whose journeys from the 1840s Kelly was following. Gregory' navigated mainly by sextant altitudes of stars, which were reflected in a pannikin of black tea, which he could then drink; which shows that the method can work in the right circumstances. I expect that the clear desert air produced suitably bright stars with dark backgrounds. Presumably, there would have to be a camp-fire lit so a colleague could read the sextant by its light and note the results, though Gregory himself would need to preserve his night-vision, perhaps by keeping his distance from the fire and putting his back to it. Gary has described well how the right star is to be found. George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---