The Rotten Rock

Jules Marcou was born in Salins, in the Jura, and by 1864 he had made his name as a geologist in America. He had published one of the first geological maps of the United States and helped the naturalist Louis Agassiz build up his new museum at Harvard. He asked Courbet to paint a spot he knew well, the Roche Pourrie, or rotten rock, on the hillside below Fort Belin. It was a local geological curiosity, a fault where a crushed yellow limestone meets a white one. Marcou had noticed that Courbet, who laid on thick paint with a palette knife, could render layers of stone with real accuracy. The fort and its bridge are tiny at the top left. The geologist is in the picture too, a small dark figure bent before the rock, so hard to make out that you have to search the boulders for him. The canvas is dated 1864, and in 1928 it was bequeathed to the town of Salins.