Flamsteed - Fortin Atlas Celeste - 1776

By Giangi Caglieris

Go to the Atlas without reading this introduction

Per accedere alla versione Italiana .

I am grateful to my friend Henk Bril , who transformed in a good English my row translation of the Italian same page.
Please, have a look on his very interesting site http://home.hccnet.nl/h.j.bril/index.html.!

Why put a celestial Atlas on-line?

XVII and XVIII' century Celestial Atlases, are among the most longed-for books by bibliophiles, especially if he is an Amateur Astronomer. That I am, and owing by luck one of these atlases, I think it is a good thing to keep it at everyone's disposal. I hope with this to set a precedent; both big organisations and institutes (such as Biblioteca dell'Osservatorio di Brera - INAF, Milan- Italy, Biblioteque Nationale du Frace Francese, Smithsonian Institution Libraries) and private collectors should put Atlases and historical books on line.

The necessary tools are available; the costs for a scanner and publishing on the Web are within everybody's reach, and so are high-speed telephonic lines (required for high resolution image transferring).

Flamsteed and the development of Celestial Atlases in the 1700's

The Flamsteed Atlas coelestis (London, 1729) was the first stellar atlas based on a telescopic catalogue. Flamsteed, the First Royal Astronomer in Greenwich, a very rigorous observer, died in 1719, leaving his works unpublished, to be published later by his widow. The Stellarum inerrantium Catalogus Britannicus (with 2919 stars, published in 1725) is the foundation of Atlas Coelestis, edited in 1729.
It scored an immediate success and was for almost a century the standard for professional astronomers: they appreciated overall the precision and the fact it was so easy to read the stellar co-ordinates. Messier, the great French astronomer, discoverer of many comets and author of a very successful catalogue of Nebulae, used this Atlas for reporting on his latest discoveries.

The Atlas is on-line at Biblioteca dell'Osservatorio di Brera - INAF

But, three objections were made with regard to Atlas Coelestis:

The big size (see photo), the high fare and a scarcely artistic quality. Thought to be work of James Thornhill, author of S. Paul's frescos in London, many constellation's figures were not artistic, some are almost grotesque (especially Aquarius).

At first, in 1745, John Bevis (discoverer of M1) tried to improve the Atlas. He prepared an Atlas in which he returned to the Bayer stile (Uranometria, 1603), with more artistic figures, updated to the latest telescopic observations (many from Bevis himself) and reduced in size.

Details on this Atlas and on why it was not officially printed can be obtained at the Manchester Observatory.

The Fortin Atlas

Another defect, once more marked by time: the stellar positions where for 1690.

Around the 1770's, the age of large developments in Astronomy, a reduced and more handy version was developed by Fortin, French and Royal mechanical engineer for globes and spheres, under supervision of Le Monnier and Messier, astronomers and members al Royal Academy for Sciences in Paris.

Comparation between FLAMSTEED ATLAS (rigth) and FORTIN-FLAMSTEED ATLAS (feft).
The FLAMSTEED ATLAS Image is from the copy in Biblioteca dell'Ossrvatorio di Brera - INAF in Milan, Italy, who we tank very much ideed.

It was presented as the second version of Flamsteed Atlas, being reduced in dimensions (1/3 of the original one, 16x23cm closed, tables on two pages, with actual dimensions 22x17,5 cm). The table's structure is the same as for Flamsteed, even the constellation figures are quite the same, but some little changes made them more artistically pleasant (overall Andromeda, Virgo and Aquarius).

Stellar positions were for 1780 and the used projection, excluding table I, around the North Pole

(Tolomeus Projection) is the same as in Flamsteed's. It is called "sinusoidal", makes distortions at high latitudes (see Ursa Major, but has the advantage that areas equivalent on chart are equivalent to areas on the sky, very useful to compare visual fields at the telescope.

The positional grid is twofold. Main, with unbroken lines, reports the Equatorial Co-ordinates, i.e. Right Ascension (R.A. either in Hours and Minutes either in degrees) and Declination (measured as distance from North Pole and not from Equator). The secondary, with broken lines, reports the Ecliptic Co-ordinates, i.e. Latitude and Longitude (the last measured in Zodiacal Signs and degrees, 30 for each sign). For instance Mu Piscis that has Ecliptic Co-ordinates: Longitude Aries, 20° (1'Th sign and 20°) and Latitude -2°, has indeed Equatorial Co-ordinates 1 hour and 25' in R.A., and 5° in Declination (distant 85° from North Pole).

Constellation names are in French, not in Latin and some nebulae, discovered after Flamsteed, are included. The tables of this atlas had been used by Messier for mapping the comets he observed (reported in many volumes of the Historie & Memories de l'Académie Royale des Sciences, Paris.

Twenty years after, in 1795, Mechain and Lalande prepared a new version, with new constellations and many new nebulae.

The nebulae reported on charts

I have identified in total 18 nebulae in the charts (all catalogued by Messier). Try to identify them and send me the list at caglieris_gm@infinito.it. Perhaps that careful investigation detects more nebulae.

Plate 10 and Poniatowski's Bull

Heck Brill found in my page a mystery in plate 10: Let he to spoke: Click here for the original page:

The mystery can be found on plate 10 of the Atlas of Giangi Caglieris and concerns the presence of Poniatowski's Bull. This constellation, created in 1777 by Abbe Poczobut from Vilnato to honour king Stanislaus Poniatowski (1677-1766) of Poland, is (obvious) not in the 1776 edition (see Linda Hall Library edition). First assumption you make is that Giangi Caglieris has a mix of the 1776 en 1795 maps, which sounds reasonable, where it not that Giangi states that this is not the case. Marc Hoffeld from Luxemburg has the same edition as Giangi. This makes it a very strange case.

I contacted Giangi Caglieris on this matter, but the mystery remained unsolved. I am no specialist in this field, but common sense leads to the conclusion that the Linda Hall Library possesses an Atlas of 1776, I posses maps from 1795, and Giangi Caglieris and Marc Hoffeld own an edition made somewhere between 1777 en 1787 (because 'Frederick's Glory' is not drawn in his Atlas). My conclusion was confirmed on January 26th 2004 by dr. Robert H. van Gent of the University of Utrecht. He stated that Poniatowski's Bull was added to the copper plates of Fortin's Flamsteed atlas in 1778. But apparently in the 1778 and later printings of the atlas the publisher evidently did not feel the need to update the title page. This information can be found in Lalande's astronomical bibliography (pp. 555-556), online at the ARIBIB website of the Astronomisches Rechen-Institut in Heidelberg, Germany. All this has been confirmed on February 25th 2004 by Felice Stoppa who has a 1795 atlas (his plates are identical with mine). He made closer examinations of the atlases of 1776, 1795 ánd Johann Elert Bode's "Vorstellung der Gestirne ... nach der Pariser Ausgabe des Flamsteadschen Himmelatlas" of 1782. And he concludes that Giangi and Marc's 1776 Atlas must be dated somewhere between 1778 and 1782. Felice also traced another copy of the 1776 edition, which is neither identical with Linda Hall nor Giangi or Marc, and because several stars are placed on exact the same location as in Bode's atlas, it has to be dated after 1782.

On December 18th 2004 I received an email from Shinobu Takesako, who lives in Japan. He owns a copy of the 1776-atlas which in fact has 2 plates 10. One with and one without Poniatowski's Bull. This leads to the following hypothesis: Apparently a new page 10 (with the Bull) was made in 1778 on authority of Fortin (?) (see the above mentioned reference to Lalande's Astronomical Bibliography and the below shown reference to his 'Astronomie', Paris 1792, on page 233 - Felice Stoppa mailed me this information on December 22nd 2004).

Prints of these were added to the stock of unsold 1776-editions. When these were sold out and new atlases had to be printed, they were printed with only the new one, because the original copper-plate had been changed.

To the Henk's considerations I will add: It was normal practice in XVII- XVIII century to sold a book as unbounded sheets, leaving to the customer the binding. In this case the Shinobu.'s copy is easily explained.

Technical details on how the on-line version has been made

The book has been digitalised with a professional photographic scanner at "Servizio Fotocopie" of Biblioteca Nazionale Braidense" in Milan, in grey (256 tones) with a resolution of 300 Dpi.
In order to reduce size and improve download speed, images have been reduced to:

- Text pages: 120 Dpi
- Constellation's tables: 150 Dpi

I added to the images my copyright (G.M.Caglieris@2002). Furthermore, I added to the constellation's tables (from 3 to 24) the image with Stellar Magnitudes (only on table 2 in original).

If you are interested in a copy on paper or on CD, please contact me at caglieris_gm@infinito.it.

Sections of Atlas

The atlas in divided into the following sections.

a) Preliminary speech and Table Index
b) Tables (30)
c) Stellar catalogue
d) Table of transit to meridian
e) Constellation identification and description
f) Astronomical problems and solutions

Navigation through the Atlas

Mainly there are 3 tools to navigate through the atlas:

Regarding the first two items: buttons are available for scrolling through the pages (back and forward). The third tool let you return to cross-reference using the RETURN function of the browser.


Copyright G.M. Caglieris 2002. All material is subject to copyright by me, but can be freely used for the non-commercial purpose of scientific or educational advancement.. All copies and electronic transmissions should cite the source and give credit to me and eventually other sources by me cited.

Comments, error notices and suggestion.

All are most welcome; please send them to: caglieris_gm@infinito.it