In one pastel, Degas evoked the thrilling height of the suspended figure with sketchy indications of the building's iron framework in vivid blue, as in the painting, but he experimented briefly with the position of the feet, pushing the front leg and the pointed foot, in its decorative boot, forward to create an emphatic vertical gesture in the lower part of the image.
WSJ: A Dizzying Artistic Feat | Edgar Degas | Miss La La at the Cirque Fernando | By Karen Wilkin