01. How to paint a boulder
A boulder seems to belong to the category of forms without design. It lacks the regularity of a building, the symmetry of a constructed object or the geometric clarity of an artefact. It appears as the outcome of a series of events: pressures, fractures, erosions, impacts, transports. Its form seems to derive from time alone.
In 1891, for the six-hundredth anniversary of the Confederation, Ferdinand Wagner painted the Battle of Morgarten on the façade of the Town Hall in Schwyz. Sources on that clash of 1315 are scarce and partly modelled on biblical tales; the boulders rolled down onto the knights belong more to tradition than to documented history. Morgarten has above all become a founding myth.
This is precisely what makes the fresco interesting. At the centre of the image there are no men. There are boulders. They are not in the background. They do not complete the scene. They fall. They halt the advance. They have weight and direction.
To achieve this effect, Wagner has to solve a technical problem before a narrative one: how to paint a boulder so that the viewer recognises it as such.
Irregularity does not seem to be enough. An irregular patch is not yet a stone.
Perhaps a succession of planes is needed, sharp edges, angles that are never right angles. The form, motionless on the wall, must give the impression that it could roll.
To make chance believable, the painter has in some way to construct it: to decide how many planes, at what inclination, in what relationship.
Decades later, in Giornico, Apollonio Pessina tackles the same problem in sculpture, with a granite boulder. With Erratico accidentale Cavenago tries another strategy: a simple rule, repeated eight times, leaves the final form to chance.
The Schwyz fresco suggests that the boulder, before being a thing, is also a visual convention: something we recognise because someone has established how to represent it.
And if the boulder is a convention, can it then be built?
Translation: Archivio Umberto Cavenago
Ferdinand Wagner the Younger, La Battaglia di Morgarten, 1891, fresco on the façade of the Town Hall (Rathaus), Schwyz
Survey of the profiles of six falling boulders, superimposed on the fresco. In none of them do two planes meet at a right angle.
Tracings: Archivio Umberto Cavenago, 2026
Tracings: Archivio Umberto Cavenago, 2026
Schwyz, Rathaus (Town Hall). The central panel of the façade shows the Battle of Morgarten (1315), a fresco painted by Ferdinand Wagner the Younger in 1891, one of the best-known commemorative cycles celebrating the birth of the Swiss Confederation.