Welcome to the NavList Message Boards.


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

Compose Your Message

Add Images & Files
    Re: HMS Bounty
    From: William Allen
    Date: 2004 May 19, 09:38 -0700

    Could you please give a little more explanation on using the sine curve
    to approximate declination?  Maybe a short example?
    Bill Allen
    -----Original Message-----
    From: Navigation Mailing List
    [mailto:NAVIGATION-L{at}LISTSERV.WEBKAHUNA.COM] On Behalf Of Fred Hebard
    Sent: Tuesday, May 18, 2004 3:21 PM
    Subject: Re: HMS Bounty
    On May 18, 2004, at 5:44 PM, George Huxtable wrote:
    > How could he have
    > done this without a table of day-by-day Sun declination, that only the
    > ephemeris or some other nautical table could provide?
    Although not accurate to the minute, one can estimate the sun's
    declination by means of a sine curve running from the equinox as zero
    degrees to the solstice as 90, with an amplitude of 23.5 degrees.  The
    ellipticity of the earth's orbit is accounted for, more or less, by the
    varying number of days between the various equinoxes and solstices.  Of
    course, how does one estimate a sine?  If one remembers the Taylor
    expansion for it, that would be one way.  It's more likely, from
    subsequent references in George Huxtable's post, that Captain Bligh had
    a short table of declinations.  An adequate one could fit on one page.
    Making heroes out of the mutineers is undoubtedly stretching the truth
    on the Bounty mutiny.  But, as captain, it was Bligh's fault, just as
    in any other catastrophe on a ship.  Apparently, however, his charms
    were no match for those of some of the Tahitian maidens!
    I told some of the boys who work with me the story of the Hawaiian
    girls swimming out to Cook's ship to "welcome" him and his crew.  Some
    of those boys are not too unlike some of Cook's sailors I would think.
    One of them was ready to go to Hawaii on the spot!  He had missed that
    Cook got there 230 years ago.
    Fred Hebard

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    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 Settings

    Posting Code:

    Custom Index

    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