NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2010 Sep 22, 08:29 -0700
George,
Yes it is Astigmatizer and not Stigmatizer. My computer says this word is spelled wrong though. Gary said that his A-7 bubble sextant has this feature so I checked my Navy MK 5 and sure enough staring me right in the face (but upside down) as I open the Navy MK 5 box is the astigmatizer lens lever with label that spells it ASTIGMATIZER. Inspection of the printed instructions states that the astigmatizer is to be flipped into place after the star or planet is identified and in the field of view ( I always go to printed instructions last as a last resort ;-) then goes on to say that it is probably best not to use the astigmatizer on the Moon unless it is full. An illustration shows a solid black bubble with a line passing through it and visible on each side -O- . Now I am thinking that astigmatizers are for use with bubble attachments on traditional sextants where rocking of the sextant wouldn't be done. The Bowditch vol. 2 glossary (1981) says nothing about how this lens is to be used only that images are elongated.
Greg Rudzinski
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