Theme: Photography at the Federal Office of Topography
Cartographica Helvetica 59 (2019) 
The present volume shows an overview of how photography was applied at the Federal Office of Topography swisstopo, which was founded in Geneva in 1838 by Guillaume-Henri Dufour. A year later, the physicist François Arago introduced the procedure called 'daguerreotype' to the French Academy of Sciences in Paris. This is considered to be the birth of photography. It was not until a quarter of a century later, shortly before the final stages of completing the 'Dufour Map' in 1863, that a report on the possibilities of using this new method for representing official cartography in Switzerland was published. Already a decade earlier, the Department of Justice and Police was the first federal authority to use photography in their work.
During the first half of the 1870s, the Federal Topographic Bureau began employing this new technology in cooperation with private photographers. At the World's Fair in Vienna in 1873, the exhibited Photographische Relief der Schweiz nach der Dufourkarte ('Photographic relief of Switzerland based on the Dufour Map') is thus by far the oldest known photographically produced official cartographic work of Switzerland. The engineer Philipp Charles Gosset had his surveying work of the Rhone Glacier photographically documented for an entire year. It was only in the early 1890s that the reproduction studio was founded under the supervision of Ernst Jeuch.
Simultaneously, the engineer Max Rosenmund undertook first attempts in 1892 to use photographically exposed glass plates for storing geometric information. Thereby, photography obtained a new function as a measuring image which could be restituted and used for constructing plans and maps. However, for various reasons it was not until the early 1920s that such works progressed from the experimental to a productive stage. Beginning in World War I, terrestrial photogrammetry was used in making topographic surveys for fortification maps in the Alpine regions. Aerial photogrammetry was tested around 1924/25 and went into production afterwards. Towards the end of the decade, the first orthophotographs were compiled from rectified single images and in three cases printed as photomaps. By order of the chief telegraph officer of the army, a total of 16 infrared panoramas were produced between 1944 and 1947.
For the development of the new national topographic map series according to the 1935 law, the sophisticated reproduction techniques played a key role and characterized the renowned high quality of the official cartographic products of Switzerland. However, the transition to a digital society during the 1970s had a major impact on the production processes: by and by, the important elements of the photochemical processes disappeared from the assortment of the photographic industry. At the same time, digital image processing took hold rapidly at the beginning of the 1990s, and by the turn of the millennium the analog photographic techniques had been replaced entirely by digital methods.
Translation by Christine Studer