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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Half horizon mirrors
From: Bill Arden
Date: 2004 Apr 27, 12:14 EDT
From: Bill Arden
Date: 2004 Apr 27, 12:14 EDT
In the case of a sextant with a truncated horizon-mirror (i.e. no
clear-glass portion to look through, just a short mirror to look past) then
presumably such a "rising-piece?" would be able to dim this "ghost-image"
of the Sun right down to nothing, if the telescope shifted far enough. You
could try it for yourself by grinding-away the unsilvered part of your
horizon mirror (though I doubt if many will...).
George
clear-glass portion to look through, just a short mirror to look past) then
presumably such a "rising-piece?" would be able to dim this "ghost-image"
of the Sun right down to nothing, if the telescope shifted far enough. You
could try it for yourself by grinding-away the unsilvered part of your
horizon mirror (though I doubt if many will...).
George
Or you could use a Davis Model 3, which has such a truncated mirror. 8^)
Bill Arden
