Topographic Map of Switzerland

The Topographic Map of Switzerland, also Dufour map, is the oldest official map of Switzerland. The Bureau of Topographical headed by Guillaume -Henri Dufour 1845-1864 published topographic map of the Swiss Confederation at 1:100 000 scale introduced the first geometrically correct image of Switzerland represents the Dufour map created parallel to the modern state in 1848, helped symbolically merging the cantons within the meaning of Swiss Dufour and is thus regarded as a work of national importance.

• 2.1 Geodetic basics
• 2.2 Topographic Basics
• 2.3 The participation of the cantons on the example of the Canton Bern
• 2.4 sheet classification
• 2.5 Reproduction and publication
• 2.6 Findings and Awards

Prehistory

During the border occupation in 1809, which was convened because of the national surveys against Napoleon, let Colonel Hans Conrad Finsler by engineer John Feer and some staff officers triangulate eastern Switzerland. The astronomer Johann Kaspar Horner and Staff Captain Heinrich Pestalozzi brought the resulting triangle mesh with the measurements of the cantons of Basel and Bern in conjunction. Until 1822, together with Pestalozzi angle measurements in western Switzerland was the first order triangulation for the Central Plateau. The missing triangulation of the Alps was due to the dangerous mountain climbs and the bad weather ( no remote view) a more difficult task. Finsler efforts led to the Diet of 1822, the National Survey declared a federal work and she seized the federal military authority. 1829 failed the test of Swiss nature-searching society itself to take all the work at hand and to finance by private patrons.

1832 took over Guillaume -Henri Dufour, the management of the federal triangulation and land surveying, which belonged to his duties as Colonel Quartermaster. He had already carried out in the French War College topographical works. Dufour's task was to unify the existing triangle measurements and mapping at the federal level to close the gaps and check the triangulation by the engineers and complementary to let as well as hand uniform federal guidelines. For example, had the cantons take the mountains in a scale of 1:50 '000, Jura and Country 1:25 000.

The Atlas Suisse as predecessor

From 1796 to 1802 the Atlas Suisse produced by Johann Heinrich Weiss, Johann Rudolf Meyer and Joachim Eugen Müller engraving appeared in Aarau. The map series consisted of 16 leaves and formed the whole of Switzerland at a scale of 1:120 '000.

The Dufour map

Geodetic basics

The astronomer and surveyor John Eschmann (1808 - 1852) created 1834-1837 due to existing cantonal networks and baseline the " triangulation primordial ", the first nationwide triangle mesh. The Eschmann 1840 published " Results of the trigonometric surveys in Switzerland » served the Dufour map as a geodetic reference system.

The 13 km route across the Great Marsh Walperswil between BE and FR Sugiez formed the base or baseline for the Dufour map. It was in 1791, 1797 and 1834 measured ( under Dufour ) consuming with measuring chains and iron bars. In order to transmit the length of the base of the triangulation, had their endpoints and other neighboring points angles are measured. From Walperswil from the endpoint in Sugiez, the Chasseral and Montoz were sighted in the era Dufour. Another stop on the Frienisberg used to calculate the distance between the Chasseral and Rötifluh.

With these intervals ( side lengths ) between the Triangulationspunkten the coordinates of the main points could then use the orientation elements, starting from the fundamental point, are derived. The base endpoints of Walperswil and Sugiez were connected to a triangular mesh (base magnification power of triangulation Primordial ), which covering the whole of Switzerland for the first time and the north of the Alps combined with the southern parts of the country. The 13 km long base line was used as a measure of the network. In the old observatory in Bern (1812-1876; fundamental point of the Swiss coordinates: 600000 / 20000046.9510817.438637 ) length and width of the fundamental point were astronomically determined and thus the Switzerland correctly positioned on the globe. At the Bern astronomically determined azimuths of points Rötifluh / White Stone, and SO Chasseral the network was oriented.

Topographic Basics

Parallel to the geodetic foundations Dufour took the topographic surveys in attack. Lack good draftsman and engraver in Switzerland judged Dufour 1838 - first at his own expense - a draftsman office in Carouge one that figured now as Federal Topographical Bureau and as a collection point for all trigonometric and served topographical works. Dufour and his colleagues first presented with great care been four patterns sheets 1:50 '000, which served afterwards as templates for the pattern sheet 1:100 000. 1842 Dufour was at the expense of the Canton of Geneva Geneva out the card, which to some extent served as a sample for the Dufour map.

The Bonn ash projection served as the basis for the Dufour map. As a high starting point in the development of the Dufour Map of 1845 and 1864 used Dufour rocks Repère Pierre du Niton in the port of Geneva. The original recordings for the Dufour map created in a scale of 1:25 000 ( in the lowlands and Jura) and 1:50 000 ( in the mountains).

The site (which in Switzerland is mostly hilly and mountainous) is displayed on the Dufour Map and Schattenschraffen assuming a Northwest lighting, making the relief effect and the rock drawings seem particularly vivid. This so-called "Swiss style " was highly praised, and brought the Topographical Bureau a number of international awards.

The employees of the cantons on the example of the Canton Bern

Several cantons took their territories according to federal regulations themselves which they received from the Confederation a contractually agreed amount. The foundations of their maps they made the Topographical Bureau for the revision to the federal card.

1853, came to the conclusion of a contract between the Confederation and the Canton of Bern. The Bernese Government put out a mapping Commission. These chose the Zurich surveyors and topographers Hans Heinrich Denzler to the chief engineer responsible for the following tasks:

• Angle measurement and calculation of a sufficient number of triangles first and second order
• Calculation of the Cartesian coordinates of the triangle points, based on meridian and latitude of the Bern Observatory
• Trigonometric height determination of the triangle points
• Insurance of the signal points "through burial of stones where necessary should be the same"
• Draft Instructions for the engineers and
• Participation in the topographic survey, if possible.

The previous federal points of the first and second order in the Bernese part were no longer usable and Denzler must therefore first order Rötifluh and Chasseral to the remote points tie.

To create a new first-order network, the Commission chose the points cup, sneezing, Berra, Rigi Kulm, warehouses, Black Horn and belts, of which the first five were part of the federal net ..

Journal of classification

As an external frame for the card work Dufour adopted a grid ( sheet classification ) of five times five leaves. Each sheet consisted of 70 km in east-west and 48 km from north to south direction. The entire map series covered an area of ​​350 x of 240 km. For the original recording in the scale of 1:50 000 a piece in 16 sections (each 17.5 x 12 km) was divided. For the scale of 1:25 000, each section was further divided into four parts ( 6 km x 8.75 ).

Reproduction and publication

The topographic Bureau delivered the original recordings were controlled by Dufour personally. Was followed by the final drawing (reduction) in the publication scale of 1:100 000 and the transmission by an engraver break on the copper plate. With Sticheln the map image was engraved on copper. After completion of the stitch successes of the copper pressure. The landforms were represented by Schattenschraffen to convey a plastic impression of space. The publication of the map series in 25 sheets ( each 70 x 48 cm) at a scale of 1:100 000 was performed between 1845 and 1865. Until 1939 published revised editions of these leaves. Maps at a scale of the original recordings were issued in 1870 under the name " Siegfried map».

Findings and Awards

The work of Dufour and his colleagues established the international reputation of Swiss cartography and was honored with several international awards.

The contemporary geographer August Petermann assessed the Dufour Map in his communications:

" The Dufour'sche map in 25 sheets combines an accurate shot with masterful nature in accordance to drawings and beautiful tasteful stitch in such an excellent manner, in such a harmonious whole, and are so close to nature image of the imposing Alps nature that we necessarily as the most excellent card See the world. "

Historians have analyzed and described the political- cultural-historical dimension of the Dufour Map: The map series represents the first geometrically correct and aesthetically beautiful image of the young federal state in 1848, a picture of both national unity and the cantonal diversity.