Johann Gabriel Doppelmayr (also spelled Doppelmaier or Doppelmair) was the son of the Nuremberg merchant Johann Siegmund Doppelmayr (1641-1686) and was born on 27 September 1677 (many early sources incorrectly give his year of birth as 1671). His father had an interest in applied physics and was one of the first to design a vertical vacuum air pump in Nuremberg.

Doppelmayr enrolled at the Ägidiengymnasium in 1689 and after completing his studies in 1696 enrolled at the nearby university of Altdorf to study law which he completed in 1698 with a dissertation on the Sun. He then attended lectures on mathematics and natural philosophy by Johann Christoph Sturm (1635-1703) which he completed in 1699 with his dissertation De visionis sensu nobilissimo, ex camerae obscurae tenebris illustrato. He continued his studies on physics and mathematics at the university of Halle where he also learned French and Italian.
In September 1700, Doppelmayr traveled to Berlin and from there, through Lower Saxony, to Holland where he visited Franeker and Amsterdam on his way to Utrecht where he stayed for a couple of months to continue his studies on physics and mathematics and to master the English language.
In April 1701, Doppelmayr went to Leiden where he stayed in the house of the astronomy professor Lothar Zumbach von Koesfeld and learned (probably in the Musschenbroek workshop) how to grind and figure telescope lenses. He then traveled to Rotterdam and in May to England where he visited Oxford and London.
After returning to Holland in the end of 1701, Doppelmayr spent another five months in Leiden, where he followed astronomy lessons from Lothar Zumbach von Koesfeld. After visiting Utrecht, Deventer, Osnabrück, Hannover, Kassel, Marburg, Gießen, Wetzlar and Frankfurt, Doppelmayr returned to Nuremberg in August 1702 and was appointed professor of mathematics at the Ägidiengymnasium in 1704, a position that he would hold until his death.
In 1723, he received an invitation to become the professor of mechanics at the Academy of St. Petersburg, but Doppelmayr declined and suggested that they should ask the Swiss mathematician Nikolaus Bernouilli for this position.

Doppelmayr died on 1 December 1750 in Nuremberg, and many believed that this was caused by the fatal effects of a powerful electrical shock which he had received shortly before while experimenting with a battery of electric capacitors. Other sources, however, suggest that Doppelmayr s electrical experiments were performed several years earlier and were not the cause of his death.

His reputation was such as to gain him memberships in the Academia Caesarea Leopoldina, the academies of Berlin and St. Petersburg, and the Royal Society of London ... His major work is the Atlas novus coelestis ... Besides star charts and a selenographic map,

Doppelmayer's Atlas includes diagrams illustrating the planetary systems of Copernicus, Tycho, and Riccioli; the elliptic theories of Kepler, Boulliau, Seth Ward, and Mercator; the lunar theories of Tycho, Horrocks, and Newton; and Halley's cometary theory' (DSB IV, p 166). 'The positions of the stars on the maps are correct for the year 1730' (Warner, The Sky Explored p 66).

Following a brief period in Augsburg, Johannes Tobias Mayer left the city in 1747 'to take up a post with the Homann Cartographic Bureau. He spent five years there, which he devoted primarily to improving the state of cartography. To this end he collated geographical and astronomical data from the numerous printed and manuscript records to which the Homann office permitted him access. He also made personal observations of lunar occultations and other astronomical eclipse phenomena, using a nine-foot-focus telescope and a glass micrometer of his own design ...

In order to facilitate the lunar eclipse method of longitude determination, Mayer in 1747 and 1748 made a large number of micrometric measurements of the angular diameter of the moon and of the times of its meridian transits. In his determinations of the selenographic coordinates of eighty-nine prominent lunar markings, he took account of the irregularity of the orbital and libratory motions of the moon and of the effect of its variable parallax' (DSB). Georg Moritz Lovits, whose plates follow Mayer's in this atlas, was equally employed at Homann's and he eventually became a partner in the company.

In 1754 he took up a professorship of practical mathematics at Nuremberg, next to Mayer. He published several works on scientific instruments and performed own astronomical observations.

The atlas

The atlas is made up of the following maps and charts (designed by Doppelmayr and published by Homann in Nuremberg :

0. Spherae artificiales synoptica idea (depicting an armillary sphere, and celestial and terrestrial globes). Augsburg, Seutter.

1. Sphaerarum artificialium typica repraesentatio (Homann's version of above print).

2. Hemisphaerium coeli boreale (with depictions of Tycho's, Hevelius', the Paris, and Nuremberg observatories in the corners).

3. Hemisphaerae coeli australis (with depictions of the Greenwich, Copenhagen, Kassel, and Berlin observatories).

4-9. Globi coelestis in tabulas planas redacti pars I [-VI] (complete set of Doppelmayer's star maps, with his calculations of the positions of the stars, as completed in 1730, in the margins).

10. Schematismus geographiae mathematicae (cartographic chart incorporating diagrams of both the Copernican and Tychonic systems, dated 1753).

11. Systema solare et planetarum.

12. Systema mundi Tychonicum.

13. Phaenomena circa quantitatem dierum artificialium et solarium perpetuo mutabilem.

14. Phaenomena in planetis primaries (the surface structure of Venus, Mars, Jupiter; Saturn's rings, comparing observations by Hevelius, Bianchini, Cassini, Halley, Hooke, Huygens, Maraldi, and Scheiner).

15. Theoria planetarum primariorum (planetary motion, mainly based on Kepler).

16. Theoria satellitum Iovis et Saturni (satellite motion).

17. Phaenomena motuum irregularium (irregularities of planetary motion).

18. Ephemerides motuum coelestium geometricae (planerary motion as per observations of 1708 and 1709, and Hooke's calculations of the distance between the Sun and Sirius).

19. Motus in coelo spirales ... pro exemplo ad annum Christi 1712 et 1713.

20. Motus planetarum superiorum.

21. Astronomia comparativa ... è Sole, Mercurio, Venere et Luna exhibentur (the phases and surface of the earth as seen from the moon).

22. Astronomia comparativa ... è planetis nostri respectu superioribus, Marte, Iove et Staurno sistuntur.

23. Tabula selenographica (large lunar hemispheres, based on Riccioli's and Hevelius' observations).

24. Theoria Lunae (detailed images of two lunar regions, lunar mechanics, and the Newtonian theory of lunar motion).

25. Theoria eclipsium (a comprehensive display of lunar and solar eclipses).

26. MAYER, Tobias. Vorstellung der in der Nacht zwischen den 8. u. 9. August 1748 vorfallenden partialen Mond-Finsternis (on the lunar eclipse of August 8 and 9, 1748). Mayer 'made theoretical and practical studies of the moon to contribute to the solution of the problem of longitude and to study the moon's surface' (Abetti, The History of Astronomy p. 145).

27-8. LOWITZ, Moritz. Vorstellung der Sonnen- oder Erd Finsternis den 25 Jul. 1748. Zweytes Blatt. Die verfinsterte Erdkugel d. i. geographische vorstellung der Sonnen- od. Erd-Finsternis den 25ten Iulii Ao. 1748 ... 1tes Blat (dated 1747 these are on the solar eclipse of the following year, incorporating Leonhard Euler's calculations).

29. Motus cometarum in hemisphaerio boreali (using the latest theories of Horrocks and Bernoulli).

30. Motus cometarum in hemisphaerio australi.

31. Theoria cometarum (introducing Kepler's, Hevelius', Petit's and Cassini's theories).

32. Cometa qui anno Christi 1742 apparuit ex observationibus, à die 13 Marty usque ad 15 Aprilis. Augsburg, Seutter.

33. Sphaera mundi.

34. Basis geographiae recentioris astronomica (tabular representation of the latest calculations of the longitude and latitude of different places in all four continents, the map incorporating a tiny section of the Australian West coast).

35. Novissimum astronomiae, geographiae, ac gnomonicae compendium theoreticum (a sundial, an astrono

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