The topographic map of the canton of Solothurn by Urs Josef Walker
Cartographica Helvetica 11 (1995) 11–17
Urs Josef Walker (1800–1855) from Solothurn, a talented mathematician, studied in Zurich, Munich and later on in Thun where he completed military courses. He was appointed as an officer and surveyor by the future general Guillaume Henri Dufour.
Walker's military career as a captain and head of the cantonal military school was only partly successful. It was Dufour personally, favouring him in the beginning, who eventually gave him poor qualifications. As an approved surveyor, Walker was quickly introduced to an illustrious circle of naturalists and scientists. In the company of the famous geologist Franz Josef Hugi and the artist Martin Disteli, he undertook several scientific expeditions to the then still virgin Swiss Alps.
In 1828 the government of Solothurn commissioned him to survey the entire canton and draw a map. Some existing results of earlier triangulations and topographic manuscript maps, surveyed by Johann Baptist Altermatt and Antoine-Joseph Buchwalder, were useful to his initial work.
His manusoript map was engraved in stone by the renowned lithographic printers Engelmann & Co. in Paris and published in 1832. The large-sized (94 x 80 cm) monochrome map in the 1:60,000 scale was used in parts as a base for the subsequent topographic map series 1:100,000 of Switzerland (known as 'Dufour map').
Another of Walker's achievements is the height map of Switzerland (Höhenkarte der Schweiz), published in 1841. He constructed these height profiles by using the results of trigonometric surveys done by Weiss, d'Ostervald, Buchwalder, Eschmann, and Berchtold, and barometric measurements taken by Saussure, Kasthofer, Merian, Hugi, and Frei.