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
    Today's octant sights
    From: Frank Reed
    Date: 2010 Mar 17, 14:32 -0700

    Here are the Sun sights I took with an old ebony octant c.1840 this morning on the shore of Lake Michigan:

    10:29:00 35-00
    10:31:35 35-23
    10:33:31 35-38
    10:35:39 35-52
    10:37:49 36-12
    10:39:39 36-27
    10:41:44 36-44
    10:43:11 36-58
    10:45:39 37-13
    10:47:23 37-29

    Times are CDT. The "watch" was 10 seconds slow, so add 05:00:10 to get to GMT. These are all Sun LL (35-00 means 35 deg 00'). Index correction was 0 since those old octants were supposed to be zeroed out every time. Height of eye was 16 feet above Lake Michigan, weather conditions near standard, and the actual location was 41d 57.6N, 87d 38.1W. The horizon was a little vague. By my reductions, the mean error in the sights is about 1 minute of arc and the standard deviation is about 1 minute of arc. Pretty good considering that this is a normal octant with no telescope and a discolored vernier that I really have to squint at to read.

    "Rapid-fire" fix anyone?

    -FER

    ----------------------------------------------------------------
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com
    ----------------------------------------------------------------

       
    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