Having several maps of both the 1776 (2, 2A ánd 2B
edition) and 1795 edition
gives me the opportunity to scrutinize them. This will absolutely take
time, so drop by from time to time to see what I've come up with.
Plate 1: the 1776 and 1795
editions are identical.
This disappointed me a bit,
but on the other hand - plate 1 (and also 28) is nothing more than
overview of the Northern (plate 28: Southern) Hemisphere. (The dilemma I
have now that I cannot be certain that I really have bought a 1776-chart
- as the seller claims - because this chart was a 'stand alone'-copy.)
Plate 10: the displacement
of some stars in the 'le Rameau et Cerbere' constellation.
This displacement was
discovered by Felice Stoppa and led to the conclusion that there are
actually 3 different printings of the 1776 edition. More on this can be
found here.
I suggest to use the designations 2, 2A and 2B.
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1776 - edition 2 /
2A
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1776 - edition
2B
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1795 - edition
3.
The original place of the 4
displaced stars can still be found. Apparently they didn't succeed in
removing the stars completely, and it is proof that the original plate
of the 1776 edition was also used for the 1795 edition. Also notice the
addition in the 1795 edition of a star just north of
ε (epsilon).
Plate 13
and 23 - The variable
star Mira in the constellation of Cetus.
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1776
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1795
Mira, is one of
the first discovered variable stars. It was discovered in 1596 by David
Fabricius, who thought it to be a nova, it's variability however was
discovered by Holwarda in 1639.
On the 1776 edition it is named 'Variante', but that name was changed in
the 1795 edition to 'Changeante'. Why this change was made is unclear.
Fact is that 'etoile changeante' is a better description for a variable
star, literally it means 'changing star'. 'Etoile variante' has a less
clear meaning: 'alternative star', and apparently this was confusing, so
the name was changed.
Nowadays one should chose 'Etoile variable'.
Perhaps the following has something to do with it as well: in November
1779 Mira had a very bright maximum of magnitude 1, what would have made
it almost as bright as Aldebaran, according to William Herschel.
So...Mira did attract a lot of attention the last decades of the 18th
Century.
There is no designation as 'Mira' (the wonderful) on either plate, as
is the case in Bode's Atlas of 1782, where also the year of discovery is
named.
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