NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Troughton's reflecting circle
From: Brad Morris
Date: 2009 May 21, 17:01 -0400
From: Brad Morris
Date: 2009 May 21, 17:01 -0400
Hi Bill I thought the definition of a "tormented sextant" was one in which the navigator so over-used the adjusting screws on the mirror that they were loose in the tapped hole. The screws had been turned so many times that the hole is worn out or deformed. I have encountered screws like this in my career, just not associated with sextants. This occurs with adjustment screws and soft materials. When the screw deforms the material, it takes a memory or a set. When the screw need be marginally adjusted in this region, the screw finds that same set, precluding adjustment. Needless to say, I went over my sextant, using the methods and practices indicated by Bowditch. It was out of alignment as received, probably due to Lecky and Troughton's messages. I adjusted it into alignment. Having done many optical adjustments on many pieces of other equipment served me well. No need to do it again, as it is treated like a precious instrument, not a common tool thrown into a drawer. Message: don't over-tighten the mirror adjustment screws. Perform your adjustments and be happy. There is no need for absolute perfection. Best Regards Brad "Confidentiality and Privilege Notice The information transmitted by this electronic mail (and any attachments) is being sent by or on behalf of Tactronics; it is intended for the exclusive use of the addressee named above and may constitute information that is privileged or confidential or otherwise legally exempt from disclosure. If you are not the addressee or an employee or agent responsible for delivering this message to same, you are not authorized to retain, read, copy or disseminate this electronic mail (or any attachments) or any part thereof. If you have received this electronic mail (and any attachments) in error, please call us immediately and send written confirmation that same has been deleted from your system. Thank you." --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---