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Dear list,

The only mistake George made is that my dissertation is not finished yet ;)
I have about two years time left for that.

Indeed, Mayers contribution was vital for the method of Lunar Distances
(LD).He was the first man to develop and publish a sufficiently accurate
method (ie, a set of tables) for the prediction of the position of the moon
at any time in the (near) future. That is, sufficiently accurate for
longitude by LD as specified by the British Longitude Act. However, Mayer's
primary concern was not with navigation but with geography; the
possibibility of a reward by the Board of Longitude was a welcome spin-off.
Although Mayer's contribution was vital, I regard Maskelyne as the more
influential man in making LD practicable. Maskelyne was the right man in
the right place to supply mariners with the tools they needed.
He combined Mayer's predictions with the Abb? de la Caille's idea of
precomputed LD tables, and he wrote a practical manual for mariners.
As Astronomer Royal he held a very influential position but even before
that time he did everything in his power to further the LD method.

Mayer learned many mathematical techniques from Euler, but his lunar theory
is in no way an elaboration of one of Euler's lunar theories (in fact,
Euler's study of the great Jupiter-Saturn perturbation was a major  source
of inspiration to Mayer). The main reason for Mayer's success is that he
managed to fit over 20 parameters in his theory to over 200 observations of
eclipses and occultations made after the invention of the telescope. In my
dissertation I want to answer (a.o.) the question how he did the fitting,
before the invention of the least squares method.


As far as I know the Connaissance des Temps used the data of the Nautical
Almanac, adjusted to the Paris Meridian of course, for its Lunar Distance
tables. I am not sure if precomputed LD's were ever published before the
first Nautical Almanac appeared in 1767. It is remarkable that the British
savants provided the data for their French colleagues in due time for the
publication of the French almanac, even in the years that Britain and
France were at war.

Steven.

   

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