La famiglia Monet nel loro giardino ad Argenteuil

That spring, Monet, Renoir and about 30 other painters had put on their own exhibition in Nadar's old photography studio on the boulevard des Capucines, the show that earned them the name Impressionists. Manet, older and far better known than any of them, declined to take part. He still wanted the official Salon.

Then in the summer of 1874 he rented a house at Gennevilliers, across the Seine from Monet at Argenteuil, and painted Monet's wife Camille and their son on the grass, with Monet himself tending the garden at the left edge.

Renoir turned up while the work was under way, borrowed paint, brushes and a canvas, and set up alongside to paint the same woman, the same boy, the same rooster. His version is in Washington. Monet meanwhile painted Manet at his easel, and nobody now knows where that canvas is.