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: Longitude sight, South Pacific, 1864
    From: Brad Morris
    Date: 2018 May 16, 20:09 -0400
    Hello Charles

    Logarithms permit multiplication by addition.  That is, instead of multiplying two numbers together, we add the logarithms of those two numbers and then take the inverse logarithm to find the same result as pure multiplication!  

    Similarly, one can divide two numbers by the subtraction of logarithms of those numbers and then taking the inverse log.

    It is a far less error prone and gets rid of those pesky, "error prone" multiplication tables.  

    Slide rules are typically logarithms realized in a physical medium, if that's any help in visualizing this!

    Brad





    On May 16, 2018 7:47 PM, "Charles McElhill" <NoReply_McElhill@fer3.com> wrote:

    I have a question regarding the use of logarithms. What was the advantage for 19th century navigation?

    You see this a lot in old navigation text. Was it just to simplify interpolation ?  Thanks

    View and reply to this message

    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