Fortin 1776


Fortin 1776
Fortin 1795 - E
Fortin 1795 - NL
Fortin - Nebulae
Fortin - Varia
Urania's Mirror
SDUK, 1851
Comets / Kometen
Varia 1
Varia 2


Fortin -Atlas Céleste 1776

In December 2004 I bought six charts of the Fortin Atlas of 1776, edition 2A to be more precise. In October 2005 I bought plate 9 - Le Serpentaire et le Serpent, and in December 2005 I bought plate 1 - Hemisphere Boreal. In September 2006 I bought plates 9 and 10 of  edition 2B. In January 2007 I added plate 23 of edition 2 to my collection. In March 2007 on two occasions I bought plate 13 - Le Bellier (edition unknown) and plate 6 - La Grande Ourse and plate 10 - L'Aigle, Antonous, La Fleche, Le Renard, Le Dauphin (both maps edition 2A).

Images of the plates I own can be found here.

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.

1776 - edition 2 / 2A

1776 - edition 2B

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.



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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