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Dear George,

> information with "Jeremy Spencer"
> . Jeremy is a
> researcher at the Australian National Museum, in Canberra, and has been
> working on Cook's surveying techniques.

I will certainly write to him.
It is very pleasant to know that there are other people
sharing this strange hobby:-)

> The map set was indeed pretty complete for its
> time, but more recently (1988 to 1997) a
> 3-volume set has appeared, "The
> charts and coastal views of Captain Cook's voyages",
> again by the Hakluyt
> Society, edited by Andrew David.

I am afraid that Purdue does not have the 1988 edition.
I combed our library very carefully.

Anyway, what I used seems to be photocopies of Cook's maps.
So the inbscriptions on these maps would not
have changes since 1955:-)

> I wonder if that's the most direct way to compare.
> How had Cook drawn that
> point on the map?

I used Cook's Astronomical observation logs.
Available on the web.
There they list all observations.
Most of them cannot be tied to certain places
whose position I can verify.

But some of these observations have very specific
places on the shore attached. Like "Point Venus".
I find this "point Venus" on a Cook map.
I suppose that this is the place whose position he
(they) determined with the most care
(Hundreds of observations are listed under "point Venus"
in the astronomical obs. log.
They had an observatory there. I suppose
that co-ordinates on the map were
all measured FROM this point
Venus, whose position they determined with such care.
Then I find this point Venus on the Terraserver.

On other maps, I used suspicious capes,
anchor stations etc.

> Society Isles that the map shows,
> Cook's journal refers to only one
> determination of longitude, at Huaheine Island

I was not using Cook's journal.
I was using the "Original astronomical Observations..."
by his associates like Bayly, and Wales and other officers
(available on the web)
to determine the points where
they made really carefull observations.

Like 50-100 Lunars with 4 sextants and 4
or 5 different people
from land.

Comparable with what I made from my balcony:-)

I used THESE points on THEIR maps.

> That's a really important question, well worth asking,
> and answering. The
> best study of such matters that
>I know of was made by Nicholas Doe, "Captain
> Vancouver's longitudes - 1792", in Journal of Navigation,

American or British?
I renently bought a CD from the American one,
and was very much disappointed. I mean I payed $50
(including delivery)
for a piece of crap. I mean there are 4-5, maximum 10
papers worth reading (from my point of view) on the whole
disc, and 3 or 4 of these
papers are available on the web for free
anyway.

My general philosophical opinion is that
"REAL science is available for free",
on the web or otherwise, is strongly confirmed
by this CD.

Sorry for this deviation from the main topic:-)


> It would be no surprise if
> corresponding errors occurred in the almanacs
> used by Cook, and it would be a valuable and
> simple exercise to discover if
> they did.

I wolud like to do this.
(I am mostly interested in sextant performance,
so I would like to seratate the sextant errors from
the almanac errors).
The hardest thing (for me) is to discover
what almanacs precisely did they use, and to find
these almanacs on the web or elsewhere.

The "true almanac" with exact positions is supposedly
available on the Frank web site.

Alex.





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