The artist worked at his lithographs [on stone!] on the easel, the stone placed like a canvas. He manipulated his crayons like brushes and never sharpened them. He remained standing, walking backwards and forwards every other minute to judge his effects. Usually he covered the whole stone with a uniform gray tone and then removed with a scraper those parts which were to appear light: here a head, a figure; there a horse, a bull. Next, the crayon was again employed to strengthen the shadows, the accents, or to indicate the figures and give them movement..