NavList:

Thanks for that Al.  That certainly makes better sense to me given how the sextant was being used in the photograph.  The explanation of the telescope in the link you provided is intersting too, especially with regard to why such a telescope was in use at all given its narrow field of view.  I am relieved that the sextant pictured was not using a 12x inverting scope (the subject of Frank's question), as at least that is consistent with my sense that they would be impractical other than on a very stable platform or on land, and thus that their intended use was specialized and limited.