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
    Name or NavList Code:
    Email:
       
    Reply
    Re: Poor Line of Position Computer/popularity of slide rule sight reduction
    From: Hein Bodahl
    Date: 2010 Jan 15, 17:00 +0100

    On 15.01.2010 14:54, Brad Morris wrote:
    
    > How does the Poor Line of Position computer compare in
    > accuracy to a Bygrave or to the more accurate tabular methods?
    
    From the book:
    http://ia351430.us.archive.org/3/items/simplifiednavig00poorgoog/simplifiednavig00poorgoog.pdf
    
    "With this instrument the calculations
    are actually performed with a few direct and
    simple movements, and with an accuracy equiva-
    lent to that obtained with four place logarithmic
    tables."
    
    > What about the speed of solution?
    
    "A comparison of these three methods shows
    the following number of book openings and aux-
    iliary figures necessary in each to obtain the re-
    quired altitude and azimuth:
    
    Logarithmic 8 openings and 45 figures.
    Aquino 2 openings and 64 figures.
    Mechanical 1 opening and 4 figures."
    
    and
    
    "With this instrument the calculation of the al-
    titude, as required by the Saint Hilaire method,
    is reduced to four (4) simple and direct move-
    ments, while the azimuth may be found by two
    (2) movements. The entire calculation is made
    on the instrument, the work is straight-forward
    and requires the writing down of one figure only."
    
    Could maybe give an idea.
    
    Just ordered the book on amazon.
    Hope it has the foldout of the computer.
    
    Hein
    
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

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

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID 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