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    Re: Sumner's Line (Navigation question)
    From: Bill B
    Date: 2006 Feb 11, 14:39 -0500

    George Wrote
    > This is a response to Bill's postings about Sumner, from George.
    > Bill has written "It is a tough read, and I find it somewhat ambiguous." I
    > disagree. Sumner seems to me the archetypal American Practical Navigator. His
    booklet is not full of fancy mathematics, but common sense, clearly
    expressed. (St Hilaire is MUCH harder going!).
    I feel like I've walked into the Monty Python "Argument" skit.  Please note,
    "...and I find it somewhat ambiguous" qualifies it as an expression of my
    feelings, not that of a professional navigator or reviewer.  Talk to to the
    Mrs. on this. No matter how illogical they may seem to you, you cannot argue
    with another's feelings ;-)
    As a litmus test, if the recounting is as clear as you state, why would list
    members or someone with Ken's background and skills have cause for question,
    or have varying opinions as the the true position being east or west of the
    > Come on, Bill, if you are really interested in what Sumner did and said, READ
    > HIM IN THE ORIGINAL ACCOUNT, not in a secondhand tinkering in Bowditch.
    If your argument is that my confusion results from an inaccurate or abridged
    recounting in Bowditch (which claims to be stated "...in Sumner's own
    words.."), that holds water for me.
    > Sumner's chart, plate III, plots his "true position as afterwards proved",
    > obtained from hindsight, which puts his position, at the time of taking the
    sight, as just about 10 miles short of the Smalls light. Though he couldn't
    know that, of course, until the lighthouse was seen.
    Hindsight is all well and good, but did Sumner no good at 10 AM.  My
    question is, at the time of his 10 AM sighting was his DR position in fact
    40 miles from Tusker lighthouse, (approximately 51d 32'N on Bowditch's
    figure 110) in your texts?
    > Bill makes guesses as to his vessel's speed. No sailing ship ever did 25
    > knots, of course. An ordinary cargo carrier of the 1830s would, I suggest, be
    > happy with a speed of 12 knots under best best possible conditions,
    > and usually much slower.
    My turn. Come on George!  In a previous post I stated seriously that there
    was not sufficient information given for a time/speed/distance calculation.
    The later post was not a guess of 25 kn, but rather a sanity check (AKA
    reducing the argument to the absurd).  Please note the  after this
    tongue-in-cheek "guess." Restated, if the ship were indeed 31' west of the
    Bowditch DR, there was no way she could make the lighthouse in the time it
    took him to do calculations plus "less than an hour."
    Ken's unanswered question (until your post) was, "Several posts agreed that
    it was not perilous since he was 31 min west of his DR, etc..  But, has
    everyone missed this, as my reading puts him 31.8min EAST (or closer to The
    Smalls light, and the rocks), or am I wrong?  Is it reasonable to make a
    case that being closer than he thought was courting disaster had he not
    discovered the LOP?"
    Clearly if he were 31.8'west of the DR stated/shown in Bowditch, he could
    not have come close to covering that distance in the estimated time span
    unless his vessel was quite extraordinary for its time.  That was my point.
    No mention of her being a maxicat;-)
    As to the long string of all caps, why shout at me? I was in agreement with
    both you and Ken as to the ships true position being EAST of the DR, even
    though working from "a secondhand tinkering in Bowditch."  If you are
    frustrated that I have not had the time to read all the history books to
    date--well so I am.

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