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    Re: Places where Slocum mentions navigation-related items
    From: Doug Royer
    Date: 2003 Dec 19, 15:00 -0800
    You guys have a talent for trivialising the momentous and complicateing the obvious.
    -----Original Message-----
    From: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Frank Reed
    Sent: Friday, December 19, 2003 14:23
    To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
    Subject: Re: Places where Slocum mentions navigation-related items

    Fred Hebard wrote:
    "What I gathered from the messages was that you interpreted Slocum's
    statements about problems with the tables as _Slocum_ having problems
    with the tables rather than there being an actual error in the printed
    tables.  Is this not correct?"

    Yes, Fred, I've described what I meant and amplified on that description in other posts on the list. Some people have had no problem at all understanding what I am talking about. I am a little amazed that you don't understand what I am saying. I would suggest you re-read what I wrote on the topic in earlier messages. Here are the archives for the list: http://www.i-DEADLINK-com/lists/navigation/

    And Fred repeats himself:
    "I conclude from this that you are inferring Slocum was fibbing?"

    Sigh... No, Fred. I said in the previous message that you are misrepresenting what I have said, and you turn around and try to put the word "fibbing" right back in my mouth. NO, I am NOT saying that Slocum was "fibbing". Got that now??

    And Fred wrote:
    "Slocum refers to lunars three times. The first at the top of the long
    excerpt that discusses the faulty tables.  Then later in that excerpt
    where the specific lunar is mentioned."

    That's one reference to lunars, Fred. Two references in the same passage refer to the same lunar. Or has your close reading turned up something else beween the lines??

    For the supposed third mention of lunars, you wrote:
    "Finally, he mentions discussing them with the Astronomer Royal in Capetown."

    No, he doesn't. He doesn't metion lunars at all. Neither the word "lunar", nor "Moon", nor even "sextant" appears in that passage. Slocum says that he discussed finding "standard time at sea" with the astronomer. Finding standard time is 100% equivalent to finding longitude. That phrase covers ALL methods of determining longitude. Might Slocum have been talking about lunars? Yes, he might have because lunars are ONE method for finding longitude at sea. And of course, we have solid evidence that Slocum attempted lunars once and the activity provided him considerable entertainment on a long, long ocean passage, and maybe he told the astronomer about that instance and his logarithm troubles, too. Unfortunately the conversation with the astronomer tells us nothing more than we already know about Slocum and his one clearly attested lunar observation.

    But there is a window here for an additional source of information. Slocum's voyage was big news at this point. He was a celebrity, and there's some chance that his conversations with David Gill were recorded. Maybe Gill kept a journal. Maybe the Capetown nespaper ran a story about Slocum.

    And Fred wrote:
    "There is specific documentation for but that one lunar, as you have pointed out."

    AND in addition, we have Slocum's specific statement that he found his longitude "mostly by intuition" and statements where he says "no observations for longitude" were made, and clear statements that he was "running down the longitude", and confirmation of longitude by encountering the Brazil Current, and two excerpts from his logbook with explicit dead reckoning navigation details. These are ALL descriptions of dead reckoning navigation. I can't prove, of course, that Slocum did not shoot many more lunars, but I am still highly sceptical of the oft-repeated claim that Slocum's primary method of finding longitude was lunar distances. That's just a misunderstanding. Slocum got longitude the same way that generations upon generations of navigators got longitude: by the delicate science of dead reckoning.

    Fred, you seem to find this significant:
    "(It also appears he took about 4-6 noon shots of the sun while circumnavigating the earth :)"

    That's a "straw man". Getting latitude by Noon Sun was the standard, well-known method of finding a ship's latitude for centuries before Slocum's voyage and decades after it. Let's suppose I keep a journal of things I see in the sky from my backyard... If I write in my journal "today I saw a total eclipse of the Sun", can you conclude that I probably saw many solar eclipses? Would you next count up the number of sunrises described in said journal? And if my journal only mentions sunrise on three dates in the year, can you conclude that there must have been many more eclipses of the Sun? After all, if sunrise was mentioned at a rate of only 3/365, and I mentioned an eclipse at a rate of 1/365, then obviously I can conclude that I saw an eclipse every third day, right?? That's what you're doing when you point out the scarcity of Noon Sun observations in SAATW and attempt to use it as evidence that there were more lunars. Those latitudes by Noon Sun were as common and as mundane as a sunrise. By contrast, a lunar was such an extraordinary thing that Slocum himself waxed poetic about it for paragraphs and wrote the best (positive) epitaph for them that we have:
        "The work of the lunarian, though seldom practised in these days of chronometers, is
    beautifully edifying, and there is nothing in the realm of navigation that lifts one's heart up more in adoration. "

    Did Slocum shoot a few more lunars on his circum-navigation? He might have, and if evidence of that turns up, I would love to see it! Did Slocum shoot lunars regularly?? Very unlikely. His own words say that he mostly got his longitude "by intuition". Were lunars his principal method of determining longitude? No... But no matter how few lunars he shot, that quotation above, his epitaph for lunars, may be Slocum's greatest contribution to the history of navigation.

    Frank E. Reed
    [X] Mystic, Connecticut
    [ ] Chicago, Illinois

       
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