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
Add Images & Files
    Name or NavList Code:
    Email:
       
    Reply
    Re: Plotting Tools?
    From: David Pike
    Date: 2019 Apr 5, 14:48 -0700

    Maybe this Russian divider is also for the same purpose, although I can't read the Russian explanation on the cover. Best regards Juergen 

    The table in picture 2 is simple ratios. Left is for lines, middle is for areas, right is for volumes.  E.g.  1:1 is the same for all three.  With the pivot in the middle the marker ought to be found against 130.  For 1:2 for lines the pivot should be 1/3 from one end.  The points at the long end will be twice the distance apart than those at the short end.  For areas the pivot will be nearer the centre, because the longer end points only need to be 1.42 (root 2) times the distance apart of the smaller end points.  For volumes, the pivot would be even nearer the centre because the wider points would only need to be 1.26 (cube root 2) times the distance apart of the smaller end points.  E.g.  If you want to double the volume of a square cube, you only need to increase the length each edge by 1.26.  Understanding the table in photo 4 is beyond my pay grade, except to say n=6 corresponds to pivot in the middle.  DaveP

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    NavList is a community devoted to the preservation and practice of celestial navigation and other methods of traditional position-finding. We're a group of navigators, navigation enthusiasts and hobbyists, mathematicians and physicists, and historians interested in all aspects of navigation but primarily those techniques which are non-electronic.

    To post a message, if you are already signed up as a NavList member, start a new discussion or reply to any posted message and use your posting code (this is a simple low-security password assigned when you join). You may also join by posting. Your first on-topic messsage automatically makes you a member, and a posting code will be assigned and emailed to you for future posts.

    Uniquely, the NavList message boards also permit full interaction entirely by email. You can optionally receive individual posts or daily digests by email, and any member can post messages by email (bypassing the web site) by sending to our posting address which is "NavList@NavList.net". This functionality is similar to a traditional Internet mailing list: post by email, read by email, reply by email. Most members will prefer the web interface here for posting and replying to messages.

    NavList is more than an online community... more about that another day.

    © Copyright notice: please note that the rights to all messages and posts in this discussion group are held by their respective authors. No messages or text or images extracted from messages may be reproduced without the explicit consent of the message author. Email me, Frank Reed, if you have any questions.

    Join / Get 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