Clemenceau remembers Monet painting the haystack series with a range of easels set up in the fields.  Monet would trot from one to the other as the conditions and light changed, achieving different effects with each easel.  "One day I saw that my light had changed.  I said to my stepdaughter: 'Go to the house, if you don't mind, and bring me another canvas!'"

Haystacks Near Giverny
Claude Monet, 1840-1926, French
The Hermitage, St. Petersburg, Russia