Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
    Re: David Thompson's Navigational Technique
    From: Ken Muldrew
    Date: 2004 Jun 1, 19:55 -0600

    Frank Reed wrote:
    
    >  2) I can't see where you got a factor of 1/2 out of
    > Maskelyne's instructions. There *is* a factor of 1/2 but it's folded
    > into the "8.73" factor. That factor (besides the 1/2) arises from
    > working in minutes and seconds of arc instead of pure angles (a.k.a.
    > radians). You'll find that 8.73 is pi/360 (with a factor of 1000)
    > which is why Maskelyne says to "abate 13" from the index instead of
    > the more common 10 or 20.
    
    I got the factor of 1/2 from the "abate 13", 10 for the log cotangent and 3
    for a factor of 2. Anyway, it's all clear to me now. Thanks for the
    explanation.
    
    Ken Muldrew.
    
    
    

    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