The royal saltworks of Chaux (Salines de Chaux) balanced the utopian with the pragmatic. Salt was taxed, and this tax provided a prominent source of income for the cash-starved ancien regime. The site was chosen between Arc and Senans for its proximity to the immense royal forest at Chaux – the wood was necessary to boil the water for evaporation. The salt comes from boiling the natural briny water from springs in the Franche-Comte.

As a royal project and prerogative, court chose architect Claude-Nicolas Ledoux (1736-1806), a prominent Parisian society architect, to carry out scheme. Built between 1775 and 1779, the plan of the project expresses an ideal order found more often in the “higher” orders of architecture such as palaces, with buildings disposed according to a rational geometry and a hierarchical relation between parts. The plan places the director’s house in the center of the site, flanked by the boiler houses. A radial arc contains workshops and the housing for the workers. The plan’s shape resembles nothing more than a “theater of work.”

The language of the architecture expresses the idea of man’s capacity to transform matter. Stone is transposed into fully plastic expression of other materials, expressive power of man’s ability to transform material existence. The buildings use the language of classicism in a general sense but depart from classical tradition in its specific effect, with the classical orders treated as kit of parts for theatrical use. For example the columns are Doric in articulation but not in proportion, more squat than a classical 1:8 column ratio, and spaced tightly together. They lack a base, and their capital is thinly compressed. The stone coursing is heavy and emphatic. A random “rubble” wall juxtaposes nature and order at entryway. The buildings are stark, emphatic, and severe. Out of the walls issue petrified fountains, stone urns “pouring” briny water, a celebrating a dynamic transformation of matter. These elements become signs declaring the function of the saltworks– an approach that would be called “architecture parlante” or literally speaking architecture.