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According to our experiments with this moon eclipse,
the records of similar observations in XIX century,
and Frank Reed's assessment of precision
of astrolabes,

"Assuming roughly two minutes error in eclipse event
timings and two minutes error in local time,
the average expected error
would be
about three minutes --less than a degree error in longitude."

and

"the world could have been
mapped in longitude with good accuracy thousands of years ago."

This is enormously more precise than
you can hope to measure by "dead reckoning" in a land travel.
(Speaking, for example of the longitude distances like
Paris-Moscow or from Rome-Beijin).

Given that the Lunar method was proposed by Hipparchus
in III cent BC, it is surprising that it was so rarely used
in the following 2000 years, as Herbert Prinz,
apparently wery knowlegeable in the history of this question,
testifies.

But I agree that speculation on "why was this so" is out
of the scope of this list. (On my opinion, this is related
to the hudge decline in the general attitude to science
in the almost 2000 period betweeh Hipparchus and XVIII century.)

Alex.

   

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