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    Re: Longitude by altitudes. was Re: How Many Chronometers?
    From: Peter Fogg
    Date: 2009 May 15, 06:29 +1000
    Thanks for those quite pertinent observations, Fred.  One of the reasons smallpox and other infectious diseases did spread rapidly following the European installation in Australia (and also, I heard recently, in Canada much the same thing happened) was deliberate infection by, for example, the donation of clothing of those who died from disease to the original inhabitants, as part of a deliberate attempt at genocide. 

    Nowadays the inherited guilt for this is attempted to be deflected by hopeful supposings that such diseases were introduced by the Moluccans, and that's the self-serving part.  Part of what's known here as the 'History Wars'.  In Oz history can be a very political subject.

    On Fri, May 15, 2009 at 3:42 AM, Fred Hebard <mbiew@comcast.net> wrote:


    I believe you're investing more power in microbes than they have,
    when you state that the absence of Eurasian diseases in Australia or
    the Americas prior to their "discovery" by Europeans is evidence for
    no prior contact.  Microbes are usually very inefficient at spreading
    from one host to another, and tend to rely strongly on close contact
    and huge numbers.  The probability of becoming infected over some
    time period given an infectious individual is usually quite low for
    most diseases.  One indication of this is that most diseases usually
    do not reach 100% of the potential hosts.

    The infectious potential of an individual changes with time, and is
    oftentimes zero except for small windows of a few weeks duration.
    Thus a sailor with smallpox would not be infectious except if a
    lesion were oozing.  Then, I would guess for smallpox, the ooze from
    an active lesion would have to be transferred to the recipient's
    skin, perhaps by exchange of clothing and blankets or perhaps by
    direct contact.  If populations of Eurasians and Australians were
    living side-by-side for years, then infection of the Australians with
    smallpox would be guaranteed.  But there are no guarantees for
    crewman from a few ships trading for a few months, and the sailors
    perhaps sleeping on board.  There's an excellent chance that no
    sailors would be infectious, even though several had had smallpox.

    One would actually have to analyze this question separately for each
    disease due to differences in pertinent epidemiological factors, and
    also consider the living arrangements of the victim population; more
    communal habits might be more conducive to epidemics.  However, my
    experience (for plant diseases) is that limited contacts of
    relatively few individuals would not result in a 100% chance of


    On May 13, 2009, at 10:20 AM, <frankreed@HistoricalAtlas.com>
    <frankreed@HistoricalAtlas.com> wrote:

    > Peter, you wrote:
    > "By their own accounts, the contact was typically brief, ephemeral,
    > and hardly conducive to the transmission of diseases"
    > Yes, sure. So for example the Norse in Newfoundland, which I
    > mentioned as a counter-example, probably did not infect any of the
    > locals since boths groups stayed as far from the other as they
    > could (or so the saga says). But you do agree that some of the
    > fanciful stories of Norse expeditions penetrating deep into North
    > America are effectively ruled out by this, right? If the contact
    > was anything but "brief and ephemeral", the European diseases would
    > have left an earlier record and would have been common in the
    > Americans by the time the Spanish arrived.
    > And you wrote:
    > "Nothing like a long sea voyage as a useful spell of quarantine."
    > Yes, but that only gets you so far. The diseases DID cross the
    > oceans, and they arrived with some of the earliest Spanish
    > expeditions.
    > In your second message, you wrote:
    > "People from the now Indonesian islands to the north of what is now
    > the Australian Northern Territory visited the Australian northern
    > coast on a semi-regular basis over several hundred years before
    > European settlement"
    > Ah, but was it "several hundred years" or only 75? The consensus
    > (for whatever that's worth) appears to be that this trade began
    > around 1720. That's not much before the main European settlement. I
    > understand that there are some folks who want to push the contact
    > back earlier, but if so, then why no plagues among the Native
    > Australians?? Or maybe there were, and they simply didn't travel
    > far because of the low population density...
    > And you wrote:
    > "Much later it was speculated that infectious diseases in general
    > and Smallpox in particular was introduced to indigenous Australians
    > by these Moluccans (one of the Indonesian islands).  Quite recently
    > researchers focusing on this question have showed conclusively that
    > this contention is incorrect."
    > Conclusively, eh? That's a pretty good trick. Myself, I would be
    > willing to entertain the model that "some" smallpox infection came
    > from the Moluccans while the devastating infections occurred in the
    > more densely populated areas of European settlement. If you choose
    > to believe otherwise, then you would have to propose that the
    > Moluccan traders somehow avoided diseases which were endemic in
    > their own islands. How would this miracle occur??
    > -FER
    > PS: you wrote: "beche de mer (sea slugs)". Do folks in Australia
    > still call these 'sea slugs'? They're sea cucumbers by modern
    > terminology, distantly related to the starfish and sea urchins, but
    > I understand that they used to classed with the true sea slugs --
    > which are shell-less snails (mollusks) like land-bound slugs.
    > Understand, I'm not objecting to whatever terminology is considered
    > normal down there. Do you call sea cucumbers "sea slugs"? And if
    > so, is there a different name for true sea slugs?
    > >

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