Auction introduction: The Impressionist and Modern Art Day Sale in New York offers a curated selection of works featuring paintings and sculptures by the leading artists of the late 19th and 20th centuries. Highlights include works by Marc Chagall, Henri Le Sidaner, Fernand Léger and Edouard Vuillard, as well as sculptures by Auguste Rodin, Hans Arp, Henry Moore and Alberto Giacometti.