The topographic survey of Schaffhausen canton 1843–1848
Cartographica Helvetica 4 (1991) 3–16
The topographic survey 1:25,000 of Schaffhausen canton for the 'Dufour map' was produced between 1843 and 1848 by the two engineers Johann Conrad Auer and Johann Jakob Müller.
Organisational problems with the Grand Duchy of Baden kept the surveys from being finished on time, which was scheduled for 1846. Because of the difficult boundary situation between Schaffhausen and the southern part of Baden, the two states settled a mutual agreement to coordinate their mapping programme. Instead of sending the finished ordnance survey sheets to Dufour's Topographic Bureau in Geneva, Auer and Müller delivered them first to Karlsruhe. Besides loosing valuable time, the Germans published their survey results in the 1:50,000 scale and with hachures instead of contour lines, which was of no use to Schaffhausen.
The original ordnance survey sheets have disappeared. The still existing cantonal map, divided in four sheets and kept in the State Archives of Schaffhausen, is a handdrawn copy of these original ordnance survey sheets.
Thirty years later, Auer's son, Conrad Martin Auer, was entrusted with a new survey of the whole state for the 'Siegfried map' in the 1:25,000 scale. The resulting fourteen sheets of this new federal map series were the first printed maps, showing Schaffhausen in a large scale.