MäDLER, JOHANN HEINRICH

(b. Berlin, Germany, 29 May 1794; d. Hannover, Germany, 14 March 1874)

astronomy.

After graduating from the Gymnasium, Mädler became, at the age of twenty-three, a seminary teacher in Berlin. His interest in astronomy had been awakened by the appearence of the comet of 1811, but he did not have an opportunity to make extensive astronomical observations until he met the rich Berlin banker Wilhelm Beer, half-brother of the composer Giacomo Meyerbeer. Beer maintained a private observatory in Berlin; and he and Mädler worked there together, mainly on lunar topography. In making their observations they used a Fraunhofer telescope with an aperture of 95 millimeters. Their joint publications gave such a favorable impression of Mädler’ abilities that, beginning in 1836, he was an observer at the Berlin observatory, then directed by Encke. Here too he worked on the topography of the moon and the planets, chiefly Mars. The most important achievement from his collaboration with Beer was undoubtedly a map of the moon and accompanying two-volume text: Der Mond nach seinen kosmischen und individuellen Verhältniseen (1837). The lunar map (with a diameter of 97.5 centimeters) is in many respects the equal of Lohrmann’s representation.

In 1840 Mädler accepted an offer from the observatory at Dorpat; he also obtained a professorship and began to publish his considerable body of work. The observatory possessed an excellent observational instrument, the celebrated Fraunhofer refractor with which Struve had determined the parallax of α Lyrae (1838). Mädler was thus led to undertake a new program of work in Dorpat and thereby to follow the tradition begun by Struve: the observation of double stars. In his Die Centralsonne, Mädler sought to provide evidence that the Milky Way possesses a central constellation. He thought the latter, represented by a center of gravity, was formed by Alcyone in the Pleiades. Mädler vigorously defended this idea, but without success, for further research disproved his views.

Mädler was also a pioneer popularizer of astronomy. After giving popular scientific lectures, in 1841 he published Populäre Astronomie, which went through six editions during his lifetime. The book was distinguished by its author’s thorough command of the material and pedagogically effective presentation of it. In contrast with most popularizers of science, who believed that “to instruct the public one needs only a superficial knowledge of the subject in question” (preface to the first edition), Mädler incorporated in his book the whole wealth of his knowledge, including that of the most recent literature. He also contributed to the dissemination of astronomical knowledge through articles in journals and newspapers. In 1888–1889—with the active cooperation of Wilhelm Foerster—the popular astronomy movement established its own institution in Berlin (the Urania Observatory); and today there is a large network of popular astronomy journals published throughout the world.

In Populäre Astronomie, Mädler had briefly sketched the history of astronomy. Following his departure from Dorpat (1865) and return to Germany, he devoted himself to this subject. The result of his labor, the two-volume Geschichte der Himmelskunde (1873), contains an extraordinary treasure of valuable historical data that Mädler had been gathering for decades. It left much to be desired, however, with regard to order and conception—probably a consequence of the author’s advanced age, as was pointed out several years later by R. Wolf (1877).

Mädler was an argumentative scientist and thus acquired many enemies. Although he had a knowledge of history, he was often skeptical of new theories. For example, he rejected the progressive developmental ideas introduced into astronomy by Kant, Laplace, and Herschel and, twenty years before the discovery of the first spectroscopic double star, he disputed the validity of the Doppler principle.

BIBLIOGRAPHY

Mädler’ writings include Lehrbuch der Schönschreibekunst(Berlin, 1825); Physikalische Beobachtungen des Mars (Berlin, 1830); Mappa selenographica, 4 vols. (Berlin, 1834–1836), prepared with Wilhelm Beer; Der Mond nach seinen kosmischen und individuellen Verhältnissen oderallgemeine vergleichende Selenographie (Berlin, 1837), written with Wilhelm Beer; Populäre Astronomie (Berlin,1841 and later); Astronomische Briefe (Mitau, Latvia,1846); Die Centralsonne (Dorpat, 1846); Untersuchungen über die Fixstern-Syteme (Mitau-Leipzig, 1847–1848). A bibliography of Mädler’s scientific papers, which number more than 150 in the period 1829–1851, is in H. Kobold, ed., Generalregister der Bände 1–40 der Astronomischen Nachrichten Nr. 1–960 (Kiel, 1936), cols. 72–74.

There are 17 letters to J. F. Encke and 8 letters to F. W. Bessel, in the Zentralarchiv of the Akademie der Wissenschaften der DDR, Berlin, Bessel Nachlass; and 46 letters to H. C. Schumacher, in the Deutsche Staats-bibliothek, Berlin, Handschriftenabteilung, Schumacher Nachlass, and other MS material in the Staats- und Universitätsbibliothek Göttingen.

Biographical material is in S. Günther, Allgemeine deutsche Biographie, XX (1884), 37–39.

Dieter B. Herrmann