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
    or...
       
    Reply
    Re: Lewis-Clark, Manny-Moe-Jack etc.
    From: George Brisbin
    Date: 1995 Dec 21, 09:21 -0500

    >Quinn wrote:
    >
    >>Someone in an introductory nav. class I recently taught wanted to know how to
    >>find a piece of property he purchased somewhere in South America using
    >>celestial, and I had to tell him I hadn't the foggiest.  Without a horizon
    >>and a clear sky, I'm lost!  BTW, I advised him to beg, borrow, or buy a
    >>portable GPS.
    >
    >Ah! what you need is an artificial horizon, and a refraction correction
    >table for altitudes above sea-level!
    >
    BIG Snip
    
    I have no problem with your remarks except for needing a horizon.  Many of
    the early surveyous used a transit for their work.  Such an instrument has
    both vertical and horozontal arcs and a leveling bubble.  Leveling the
    transit on its' tripod and being on solid ground as opposed to being on a
    rolling boat negated the need for a visiable horizon.  Leveling the
    instrument set the horizon.
    
    Surveyors as late as 1960 were taught how to go into the field and by using
    their transit and a Ephemeris (their version of of the Nautical Almanac) to
    locate their position described by latitude and longitude rather than
    reference to the local grid system.  The outter banks of North Carolina were
    surveyed using this method. They established control points (posts) and then
    used triangulation from one post to the next to fill in the details.  At one
    time I had copies of the original surveys done for the Coast and Geoditic
    Survey section of the Government in the 1850's.  This was the second mapping
    of the coastline in this area, the first being done in the late 1700's.
    
    I have a copy of a surveying book by Michael V. Smirnoff called
    "MEASUREMENTS FOR ENGINEERING and other surveys" (1961) that gives about
    thirty pages of this type of navagation (land).  Anyone wishing a fax copy
    of this work can have one by sending me your fax number (or snail mail
    address). I will send it. (Copies will be for historical purposes only and
    are not to be sold or reused in any work without permission from
    Prentice-Hall Inc publishers who still have current copyrights to this
    material)  I will be away until Jan 9th so be patient.  Just a note.  George
    Washington set a portion of the southern border of Virginia running a
    lattitude line using a transit and the methods used in the text.  The
    methods had not changed much in the intervining two hundred years to that
    point.  They have really changed since.
    
    Best of the Christmas Season to all. (Micah 6:8)
    
    George
    
    >Cheers!
    >
    >J.
    >
    >P.S. -- unless you live in California, the Earth doesn't move much ;-), so
    >you can do a multiple body fix using only the sun throughout the course of
    >the day...
    >
    >------------------------------------------------------------------------
    >This mail list is managed by the majordomo program.
    >To unsubscribe from this list, send the following message
    >to majordomo{at}ronin.com:   unsubscribe navigation
    >For help, send the following message to majordom{at}ronin.com: help
    >Do NOT send administrative requests to navigation{at}ronin.com. Thanks. -ben
    >------------------------------------------------------------------------
    >
    >
      JOY... Quartering wind at 10 to 15 knots, Temperature 78 F, Sea State less
    than 3' , full moon
     sky full of stars, a bone in her teeth, and a wake of phosphorescence fire
     :-))).
    
    ------------------------------------------------------------------------
    This mail list is managed by the majordomo program.
    To unsubscribe from this list, send the following message
    to majordomo{at}ronin.com:   unsubscribe navigation
    For help, send the following message to majordom{at}ronin.com: help
    Do NOT send administrative requests to navigation{at}ronin.com. Thanks. -ben
    ------------------------------------------------------------------------
    
    

       
    Reply
    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