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Gary Lapook writes:

It has been almost 30 years since I read Wright's book so I don't
remember many details of  it except for the few pages that I
photocopied. Part of the book discussed his voyage to the Azores with
Lord Cumberland so he may have done some astronomical observations
ashore there.

Comparing Wright's longitudes with modern longitudes for the Lizard
and for Santa Maria (I've landed for gas at the airport there) in the
Azores, Wright shows a difference in longitude of 19� 50' while modern
longitudes make in 19� 52', a difference of only two minutes (and this
depends on which point of Santa Maria you choose) so, in fact, no
difference! How did he get this accuracy, dead reckoning couldn't do
it.


gl

On Nov 29, 4:03 pm, "Peter Fogg"  wrote:
> George writes:
>
> > I doubt if any longitude could be determined to better than a
> > degree or two that way, but even so, that would be better than dead
> > reckoning.

On Nov 29, 4:03 pm, "Peter Fogg"  wrote:
> George writes:
>
> > I doubt if any longitude could be determined to better than a
> > degree or two that way, but even so, that would be better than dead
> > reckoning.
>
> Given that "a degree or two" amounts to 60 to 120 nautical miles, surely
> this is a bit of a sweeping generalisation?
>
> My own readings indicate that navigators who had to depend on dead reckoning
> managed much better results than this.  Again, this depends on the specific
> circumstances; if crossing vast oceans without any correction then yes, a
> degree or two could be a modest error in those circumstances.
>
> The voyaging we are considering here, from the Azores northeast towards
> Britain, is more modest in scope, and a significant component involves a
> change in latitude rather than longitude.
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