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    Re: About time - Antarctica
    From: Lu Abel
    Date: 2012 Mar 5, 15:15 -0800
    The photo indeed shows Perry taking soundings, comments on their losing their weight and instead using axe heads as weights, etc.   But no where do they answer Bruce's question:  how did they know when the weight landed on the bottom?  

    For the sounder (person, not electronic device) to know that he had hit bottom, there would have to be a significant lessening of weight on the sounding wire.   That begs the question of how much 9000 feet of piano wire (what gauge?) weighs versus one or two axe-heads.

    Lu


    From: Gary LaPook <garylapook---.net>
    To: NavList@fer3.com
    Sent: Monday, March 5, 2012 2:57 PM
    Subject: [NavList] Re: About time - Antarctica

    See Peary's measurements of depth on page three:
    http://www.northpole1909.com/davies.html

    gl



    --- On Mon, 3/5/12, Lu Abel <luabel{at}ymail.com> wrote:

    From: Lu Abel <luabel{at}ymail.com>
    Subject: [NavList] Re: About time - Antarctica
    To: "NavList@fer3.com" <NavList@fer3.com>
    Date: Monday, March 5, 2012, 11:29 AM

    Good question.   Or, for that matter, when they say the Marianas Trench is 35,000 feet deep, how did they measure that?   Too far, I would presume, for sonar.

    Lu


    From: Bruce Pennino <bpennino.ce---.net>
    To: NavList@fer3.com
    Sent: Monday, March 5, 2012 10:49 AM
    Subject: [NavList] Re: About time - Antarctica

    They were measuring 1000s of feet of depth. How could they "feel" when the object touched or  bounced off the bottom?

    Bruce J. Pennino, P.E.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
    ----- Original Message -----
    Sent: Monday, March 05, 2012 12:27 PM
    Subject: [NavList] Re: About time - Antarctica

    Very much like using a hand lead line except it was a much heavier weight on a long wire which was on a motorized reel. This device was called a "deep sea lead."

    gl

    --- On Mon, 3/5/12, Bruce Pennino <bpennino.ce---.net> wrote:

    From: Bruce Pennino <bpennino.ce---.net>
    Subject: [NavList] About time - Antarctica
    To: NavList@fer3.com
    Date: Monday, March 5, 2012, 7:50 AM

    Just finished reading The Storied Ice by Joan Boothe. A very  good  overview book about all major explorations of Antarctica; many references.
     
    Anyway, Antarctica explorers had a longitude problem. In 1926-27 the Discovery "was the first vessel in these waters capable of receiving Greenwich time signals directly, and her men used the signals to check longitudinal positions on the maps."   Only Deception Island was properly located.
     
    Also,as the early explorers headed south ,they measured water depth for various reasons. How did they measure depths of several thousand feet with a drifting ship, angle of cable, flexibility(springiness)? 
     
    Boothe gives a brief overview of Cook's explorations....she says he was an extraordinary man. 

    Bruce Pennino
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     




       
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