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    Re: Nevil Maskelyne.
    From: George Huxtable
    Date: 2004 Jul 17, 18:00 +0100

    Somehow, I doubt if Frank Reed and I are going to agree much, if at all ,
    about the virtues (or otherwise) of Sobel's book "Longitude".
    Indeed, Trevor Kenchington has expressed many of those reservations about
    the book, much better than I could have done.
    But I think there's still some point in dissecting some of Frank's arguments.
    I wrote the following about Sobel's Longitude.
    >"It attempts to explain a highly-technical subject to the lay reader without
    >the aid of explanatory diagrams. As a result, that reader is likely to emerge
    >without really understanding much more about the determination of longitude
    >than when he went in. "
    and Frank replied-
    >That's only a speculation...
    Well, a bit more than speculation, actually. Here's one piece of evidence,
    The RIN issues a bimonthly "Navigation Newsletter" (as well as their more
    serious Journal of Navigation). In the issue dated November/December 1996
    was a review of Sobel's "Longitude", by Phil Barton. Not a name that I
    know, but presumably an experienced navigator who was sufficiently
    confident of his own knowledge to review such a book in a navigational
    After discussing Harrison's history, he continued-
    "A timepiece for establishing longitude on a sailing vessel had to
    withstand changes in temperature and the frequent strains imposed on it by
    rough seas, and had to keep very accurate time. The procedure was to set
    the timepiece at the point of departure- say London. The local time of the
    vessel's position was calculated by means of the lunar distance, based on
    measuring the motions of the Moon. The difference in time could be measured
    in degrees, minutes, and seconds east or west of the point of departure.
    The lunar distance calculations were very long, tedious, and
    Well, how wrong can you get? And this was from a navigator who had read
    Sobel's book with the intention of reviewing it. It hadn't done much for
    HIS basic understanding, had it?
    Frank continues-
    >...Would diagrams have helped?
    >I don't think that there are many places where they would have helped a lot,...
    >By the way, I've just browsed the chapters on longitude and lunars in
    >Bowditch, Norie, Lecky, and Dunraven. They contain almost no "explanatory
    >Does that mean they're bad books? Dunraven has the most diagrams (four, I
    >think), and wow are they ever confusing!
    Well, Lecky dismissed lunars as outdated, and that was that. I wouldn't
    expect explanatory diagrams from him. I agree about the confusing nature of
    Dunraven's diagrams, but at least he tried. Contrary to what Frank said
    about Norie, my 1900 edition of Norie shows 6 diagrams to illustrate his
    lunar examples, though not much more explicit than Dunraven's. Raper shows
    3 diagrams referring to lunars. My Bowditch is too modern to give more than
    a couple of paragraphs on lunars, and no diagrams.
    But those were texts for professionals, in the days when engravings were
    restricted and expensive. Sobel was writing for the common-man, in an era
    when pictures-with-text is easy and expected, and can be worth thousands of
    words. All that was needed was a couple of line-diagrams such as Howse put
    into his Maskelyne biography, and repeated in his contribution to "Quest
    for Longitude". But the only pictures that appears in my edition of
    "Longitude" are for decoration, not illustration.
    Now for Shovell's convoy's collision with the Scillies, which lost the
    Admiraly 4 ships and 2000 lives (accounts differ about the numbers).
    Frank says-
    >And George H wrote:
    >" Sobel attributes the destruction of Shovell's fleet on the Scillies to a
    >failure in longitude.
    >Nothing could be further from the facts. "
    But he gets on to weak ground in his reply, when he said-
    >Perhaps. Old legends die hard. For over 250 years, those shipwrecks were
    >widely blamed on a failure in longitude, and many professional navigation
    >historians still routinely describe them that way today. Certainly when I
    >first heard
    >the tale of the wrecks in the late 1970s, it was told almost exactly the way
    >Sobel relates it in "Longitude".
    Well, just because Frank Reed learned it that way then, doesn't make it
    true. Who are the "many professional navigation historians"?
    He continues-
    >The Board of Longitude and the Longitude Prize
    >themselves were a direct response to the Shovell disaster. For a recent
    >example, Alan Stimson, former Curator of Navigation at the National
    >Maritime Museum
    >(Greenwich, UK) in "The Quest for Longitude" wrote: "Flamsteed ... was
    >directed to 'apply himself with the utmost care and diligence to rectifying the
    >tables of the motions of the heavens and the places of the fixed stars so as to
    >find out the so much to be desired longitude of places for perfecting the
    >art of
    >navigation'. A series of maritime disasters, culminating in the wrecking of
    >part of a returning squadron of naval ships under the command of Sir Cloudesley
    >Shovel (ca. 1650-1707) on the Scilly Islands in 1707, eventually led to the
    >British Parliament setting up a committee to examine the problem. This, in
    >turn, resulted in..." the Board of Longitude, the prize, and so on.
    >Elsewhere in the same volume, William J.H. Andrewes, Curator of the
    >Collection of Historical Scientific Instruments at Harvard University
    >mentions the
    >irony of testing Harrison's H1 at a location "not too far from where Sir
    >Clowdisley Shovell had been shipwrecked 29 years earlier". In a footnote
    >to that
    >comment, he adds "This disaster took the lives of 800 men, including that
    >of the
    >admiral. Although possibly not directly related to an ignorance of solving the
    >longitude problem, this event emphasized the importance of solving the
    >problem and served to stimulate the British government's decision to offer a
    >large reward for a solution."
    >That statement 'possibly not related' is fair. The point is clear; experts in
    >navigational history still routinely refer to the Shovell disaster in the
    >context of the longitude problem. A footnote about the ironic likelihood
    >that it
    >was a case of an error in latitude would have been very appropriate in Sobel's
    >book, but your assertion that this is evidence of the book's failings goes
    >too far.
    Well, it can be seen that in both quotations from the "Quest for Longitude"
    above, both contributors are careful to avoid attributing the Shovell
    disaster to an actual error in longitude. They point to it as a cause of
    public concern about inadequacies in navigation, one of the consequences
    being the setting up of the Board of Longitude and the Prize, and that is
    undeniable. But that doesn't imply that ignorance of longitude caused the
    Shovell tragedy, or that possession of a chronometer would have avoided it.
    It didn't, and it wouldn't.
    That doesn't inhibit Sobel from stating-
    "But as the sailors continued North, they discovered to their horror that
    they had misgauged their longitude near the Scilly Isles." No ifs and buts;
    according to Sobel it was a longitude error.
    Spending 5 minutes with a chart of the Western Approaches, and a bit of
    thought, should make it obvious to anyone that vessels coming from
    Shovell's departure (Gibraltar) and aiming up-channel, should have turned
    East(ish) long before reaching the LATITUDE of the Scillies.
    What was impressed on navigators in those pre-longitude days was the
    importance of the "three L's", Log, Lead, and Latitude. In continued thick
    weather, latitude was unavailable to Shovell's navigator. Unless he saw
    Ushant, his log readings would have been of little use either. Shovell must
    have neglected the Lead, which was inexcusable in those circumstances. It
    would have to be the dipsey (= "deep-sea") lead, which may have
    necessitated heaving-to on each occasion, but it would have saved the
    Sobel refers to Rupert Gould's "the Marine Chronometer" as one of her
    sources. Gould adds to his account of the Shovell disaster, in a footnote-
    "A story was current, long afterwards, that a seaman of the flagship had
    kept his own reckoning, which showed that they were in a dangerous
    situation, and that on his making this known to his superiors he was hanged
    for mutiny, there and then." Gould adds "Credat Judaeus Apella", and I
    would be grateful for a translation of that tag from some more learned
    Sobel relates this rather implausible tale, not as "a current story, long
    afterwards", but as straight fact. This "sexing-up", as we have recently
    learned to call it, is the trademark of the journalist or spin-doctor,
    rather than a reteller of history. Of course, she may have found harder
    evidence elsewhere, but as she doesn't give a reference, we will never
    know. It's an unlikely event to class as a mutiny, unless the seaman
    refused to obey orders. For a homeward-bound vessel a few days from port,
    it seems unbelievable that the Admiral would order an immediate hanging,
    when the maximum summary punishment at has disposal was 12 lashes (see "The
    Wooden World", N A M Rodger).
    contact George Huxtable by email at george@huxtable.u-net.com, by phone at
    01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
    Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.

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