J. G. Lehmann's system of slope hachures - an investigation on the quality of relief representation at the beginning of the 19th century

摘要

J. G. Lehmann (1765- 1 811) created a mathematically well founded slop hachure system that undoubtedly had a paradigmatic effect on the theory of cartographic relief presentation. Lehmann was providing an optimal solution for the typical relief conditions in central Germany. Advantages and disadvantages are clearly visible on visual inspection and ca rtometric measurement of Lehmann's original maps. In addition to the Saxon hachured maps, the (first) French map sheets with Lehmann hachures are included. As with the Saxon maps, the French maps accurately represent the slope in 5° zones. The representation of the character of the landscape is cartographically correct. The representation of individual features (mountains, hills, valleys, etc.) is oversimplified in some cases.