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    Re: long lost lunars
    From: Fred Hebard
    Date: 2003 Dec 8, 10:05 -0500

    ------------------------------------------------------------------------
    Frederick V. Hebard, PhD                      Email: mailto:Fred{at}acf.org
    Staff Pathologist, Meadowview Research Farms  Web: http://www.acf.org
    American Chestnut Foundation                  Phone: (276) 944-4631
    14005 Glenbrook Ave.                          Fax: (276) 944-0934
    Meadowview, VA 24361
    
    On Dec 7, 2003, at 10:13 PM, Frank Reed wrote:
    
    > Bruce Stark wrote:
    > "In the way we work our lunars you and I are at different ends of the
    > spectrum. I do everything the old way, not even graphing or plotting.
    > I find it satisfying to work observations the way the old navigators
    > did."
    >
    > I haven't been able to descibe all the approaches I've experimented
    > with in the brief time I've been on this list. I may have given the
    > impression that I'm in favor of computer solutions for lunars, but
    > that isn't the case. There are many options.
    >
    > And:
    > "But this approach is not going to take the world by storm. Most
    > people shy away from anything that calls for a skill they don't
    > already have, and the present generation has no skill at
    > pencil-and-paper calculation. They've had no reason to develop it. The
    > recruitment that will keep sextant navigation alive (and perhaps help
    > put the history of navigation on an honest footing) will almost
    > certainly come at your end of the spectrum."
    >
    > Anyone interested in celestial will eventually try the paper methods,
    > and since it is no longer a "practical" art, I think it's very likely
    > that more students will want the historical techniques instead of
    > electronic approaches and also they will likely bypass mid 20th
    > century methods like the highly refined H.O. tables.
    >
    > There are a number of reasons why we need computer solutions for
    > celestial navigation alongside the paper methods:
    > 1) Some celestial enthusiasts really have no interest in the
    > calculation. They want to see themselves handling a sextant, learning
    > to take sights with skill, but the reduction is somebody else's
    > problem. Those people are part of the market, so I don't disdain their
    > preference.
    > 2) A quick reduction with a few dozen strokes on a keyboard (or a cell
    > phone!) means you can take many more sights. Practice makes perfect,
    > and you can practice shooting lunars anytime when you get instant
    > feedback from electronic reduction.
    > 3) When you have a computer solution, you can do a ten-minute
    > introduction to lunars for students, friends, etc. They can see it in
    > practice and quick. Then those who want to can learn whatever paper
    > method suits them as time and interest permit.
    >
    > You also wrote:
    > "The only thing I take exception to is the idea that navigators had to
    > have a chronometer to see them through the four days or so of the dark
    > of the moon. Dead reckoning saw them through. Dead reckoning gave the
    > continuity the chronometer provided for later generations. The purpose
    > of nautical astronomy was simply to correct the reckoning now and
    > then. That kept it from drifting dangerously far from the truth as the
    > weeks and months went by."
    >
    > What I was getting at though is the next step beyond dead reckoning.
    > Yes, dead reckoning saw them through, and it's good enough to sail
    > around the world. It's what Slocum used for longitude as late as the
    > 1890s (plus one lunar distance). But accurate navigation is founded on
    > one simple thing: money. It's all about money. A ship that had
    > accurate longitude approaching a coast at New Moon could sail with
    > confidence and speed and get its cargo to port ahead of its
    > competition. DR was a start, but to beyond that they needed lunars AND
    > chronometers.
    >
    > By the same argument, for most smaller vessels, there was more profit
    > to be made by accepting a little risk and relying on dead reckoning
    > alone for longitude instead of spending money on a superior sextant
    > for lunar distance observations or, even more pricey, a chronometer.
    >
    > And why is celestial navigation almost over and done with today?
    > Because of price. When the price of two GPS receivers fell below the
    > price of one sextant, the show was over.
    >
    > Frank E. Reed
    > 75% Mystic, Connecticut
    > 25% Chicago, Illinois
    >
    >
    
    
    

       
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