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    Re: Artificial horizon question
    From: Gary LaPook
    Date: 2009 Apr 20, 02:51 -0700

    Hi Jackie, I'm in Como Italy right now,
    On Apr 20, 9:12�am, "Jackie Ferrari"  wrote:
    > I've got good results for the moon and sun in a bucket of water on calm days
    > . I once tried a star and managed its reflection ok using the method Gary
    > mentions. This was in Italy up in the mountains so no light pollution but I
    > do recall the reflection was still very faint and the results not too good.
    > Jackie.
    > ----- Original Message -----
    > From: "Gary LaPook" 
    > To: 
    > Sent: Monday, April 20, 2009 2:44 AM
    > Subject: [NavList 7993] Re: Artificial horizon question
    > > Mercury has traditionally been used for an artificial horizon (see Lewis
    > > & Clark) and it is easy to shoot stars using Mercury. It is rather hard
    > > to come by these days and is not cheap and some worry about its safety
    > > (I'm not one of them if used with care.)
    > > The second part of your question, compute in advance the approximate
    > > altitude of the star, double it and set your sextant to this value and
    > > then look for the star in the reflecting pool. The navigational stars
    > > are well separated and are bright so there should be no trouble in
    > > getting the right star.
    > > gl
    > > P H wrote:
    > >> Dear NavList Members,
    > >> Since the nearest ocean is hundreds of miles away from where I live, I
    > >> must use an artificial horizon in order to work with my sextant. �A
    > >> pan filled with water works fine enough for me for observations of the
    > >> moon at night and the sun. �Now these days both the sun and the moon
    > >> are simultaneously visible during the day, which would allow for a fix
    > >> on one's position - if the altitudes of both bodies can be measured.
    > >> As you probably can guess, with all the glare I was unable to observe
    > >> the reflection of the moon... so here is my question: are there any
    > >> tricks that would allow one to construct a usable artificial horizon
    > >> for the daytime observation of the moon? �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?
    > >> Many thanks.
    > >> Peter Hakel
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