The Digital Bernhard Schmidt Archive of the

Hamburg Observatory

One of the most important names in 20th century optics is Bernhard Woldemar Schmidt (1879-1935). His invention in 1929-1930 of the “Schmidt Camera” – a revolutionary wide-field imager of unprecedented sharpness and photographic speed – altered the course of modern astronomy and cosmic physics, allowing scientists for the first time to survey the entire sky in broad swaths, and thus to find unimagined troves of new celestial objects. It is no exaggeration to say that modern astronomy would have fumbled in the dark without the work of Bernhard Schmidt.

Schmidt developed his camera at the Hamburg Observatory (Bergedorf), with which he had a long professional connection, from 1916 onward. Because of his links to Bergedorf, Schmidt who was a maker of astronomical instruments and optical designer, regularly obtained a variety of contracts, large and small, for a great diversity of instruments. At latest from 1926 onwards, he became a guest collaborator at the observatory, and from 1931 he actually lived and worked there.

For the Hamburg Observatory, Schmidt conceived and built in the years following WWI: a large horizontally mounted reflecting telescope with mirrors of 11 and 31-meters focal length, as well as siderostats containing flat mirrors and a clepsydra-actuated clock drive. Subsequently, he executed diverse projects utilizing or applied to pre-existing optics, and also developed new optical systems. After the erection of his own work space at the Hamburg Observatory, in 1930 he re-ground the photographic objective of the Great Hamburg Refractor. And it was here that he originated the Schmidt Camera, some years later also creating the optics for the Hamburg double reflector, containing two 60-cm reflecting telescopes, one of which was a Schmidt camera. In 1927 and ’29, he took part in two solar eclipse expeditions for the observatory. Other significant projects of his included the production of reflecting telescopes for Altenburg Observatory, the Astrophysical Observatory at Potsdam, the Photo-Chemical Observatory of the Royal Technical College Berlin, as well as for the Vienna University Observatory, and the Štefánik Observatory in Prague. For the Leiden Observatory he ground a large refracting objective. Apart from his optical works, Schmidt also experimented inter alia with alternative wind-propulsion drives for boats.

Schmidt maintained a connection with numerous astronomers of the day, among whom we may name as representative: Hermann Carl Vogel (1841-1907), Karl Schwarzschild (1873-1916), Ejnar Hertzsprung (1873-1957), Walter Baade (1893-1960), Bengt Strömgren (1908-1987), and his patron, Richard Schorr (1867-1951), then director of the Hamburg Observatory. In Schmidt’s latest years from 1926 onward, Schorr effectively employed him. After Schmidt’s death at the end of 1935, Schorr assembled and preserved his business correspondence, technical drawings, astrophotos, etc., and secured the items of his work space, which was located in the observatory’s administration building.

 In recent years, Walter Stephani (Kiel) and Roger Ceragioli (Tucson) have began working on a biographical study of Bernhard Schmidt. Preparatory to this, in addition to the digitization of the materials collected by Schorr and preserved at the observatory, they have examined, cataloged, and digitized archives assembled by Schmidt’s first biographer, Arthur Arno Wachmann (1902-1990), and by Schmidt’s nephew Erik Schmidt (1925-2014). The descendants of Wachmann and Schmidt have generously donated their materials to the Hamburg Observatory for future preservation.

These documents and materials, as well as others stemming from private sources, will be kept at Hamburg. They comprise the most important resources for the biographical study of Bernhard Schmidt, and moreover, provide rich fonds for research into the development of astronomical/optical technology, and the social history of the first half of the 20th century.

In collaboration with Dr. Detlef Groote, W. Stephani and R. Ceragioli have decided to make all the documents, images, instruments, and artifacts pertaining to the life and works of Bernhard Schmidt, found at the Hamburg Observatory, researchable online. By means of the Digital Schmidt Archive at Bergedorf, this treasury of sources will become publicly accessible.

In what follows, you will arrive at a search page. Here you may perform thorough searches of the collections, employing diverse search criteria. Under “Detail View,” scans of the documents will be presented. They may be downloaded. And in this connection, we refer you to the legal notices presented on the copyright page.

 To rummage in the archive