Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: A sextant calibrator
    From: Antoine Couëtte
    Date: 2011 Feb 14, 07:37 -0800

    RE : http://www.fer3.com/arc/m2.aspx?i=115656
    [NavList] A sextant calibrator
    From: engineer---net.nz
    Date: 13 Feb 2011 14:44

    Dear Bill,

    Congratulations on all your Sextant achievements ! They are ALL quite impressive, whether your repairs themselves, or your magnificent books. All highly speak about the qualities of their Author.

    Just one question here which has puzzled me for years and even (many) decades.

    Sextants "deliver" angles in degrees, minutes and tenths of arc-minutes, at least for the past one hundred years.

    Why on Earth are their eccentricity calibration data then - for what I could observe on (very) many of sextants earlier used - ALWAYS given in arcseconds ? Why are they always given under the form of a table, when a "curve" graduated in arcminutes and tenths of arcminutes in regard of angles would be much easier to immediately use.

    As we all know, there are times - and especially if and when working under pressure - ANYTHING which will make the Navigator task even just a bit easier is most welcome.

    Never have I seen anywhere any convenient Sextant eccentricity curve, to an extent that when I knew I would likely be using a Sextant for some extended period of time, everytime I would made such a curve from the tabular data given in arc seconds ... it takes less than 5 minutes and makes your days and mostly your evenings (much) easier afterwards.

    Any idea on your side as to why so much care has been taken for design and accuracy and why what would have been a quite appreciated "cherry on the cake" is unfortunately (most ?) always missing ?

    ... not even 5 minutes !

    Is it simply because the Designers and Manufacturers, Troubleshooters and the so important Quality Control Technicians are not the End-Users ???

    Thanks for your Kind Attention, thanks your view-point on this matter, and

    Best Regards from


    Kermit

    Antoine M. "Kermit" Couëtte


    ----------------------------------------------------------------
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com
    ----------------------------------------------------------------

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site