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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: mirror horizon
From: Fred Hebard
Date: 2011 Mar 23, 16:53 -0400
From: Fred Hebard
Date: 2011 Mar 23, 16:53 -0400
Patrick, Three leveling screws would be easier to operate. In fact, one often only needs to operate two of the three to level a device. Of course a bubble level is easier to use than a uni-directional level. Perhaps course level with a bubble level and then fine with the machinist's. Fred Hebard at the other end of your state, about the same latitude. On Mar 23, 2011, at 4:16 PM, Patrick Goold wrote: > I have finally put together an artificial horizon using a front- > surface mirror. My hope is to be able to do star and planets > sights with it, which I cannot do with my Davis artificial > horizon. I found an inexpensive optical quality mirror on-line. I > drilled and tapped four holes in a cheap polypro cutting board for > inch-and-a-quarter-long 3/8th-inch machine-thread bolts to serve as > levelers and then attached the mirror using standard bathroom > mirror brackets. The trick will be getting the thing adequately > level. William Morris kindly supplied me with a very sensitive > level vial. It is not mounted to the device. I set it diagonally > across the mirror and level it, move it to the other diagonal and > repeat, switch it end to end and repeat both those steps and then > repeat as necessary. A picture of this simple apparatus is > attached. Any suggestions about how to improve it (without vastly > increasing its cost) would be welcome. > > I haven't yet taken any sights using it. It takes twenty minutes > to level the thing, sitting at my dining room table. That is, > provided no one is moving about on the ground floor of my house > while I am doing it. The level is very sensitive. It will not be > easy getting it set up outside. > > > > -- > Dr. Patrick Goold > Department of Philosophy > Virginia Wesleyan College > Norfolk, VA 23502 > 757 455 3357 > > Charles Olson: "Love the World -- and stay inside it." > >