Daphne Barbour, senior conservator, department of object conservation, National Gallery of Art; Lisha Glinsman, conservation scientist, scientific research department, National Gallery of Art. The Simpson Collection at the National Gallery of Art is one of the few remaining private collections assembled with the participation of artist Auguste Rodin (1840-1917). Most of Rodin's sculpture is sand cast, the main method used in Paris since the mid-19th century, and he usually worked with the foundry established by Alexis Rudier. Jean Limet, a painter by trade, became the appointed patinator of Rodin's bronzes and photographer of his work. In a joint presentation recorded on February 23, 2015, senior conservator Daphne Barbour and conservation scientist Lisha Glinsman focus on seven bronze sculptures cast during Rodin's lifetime and gifted by Mrs. John W. Simpson (1869-1943), including the notable works A Burgher of Calais, The Kiss, The Thinker, and The Walking Man. Barbour and Glinsman discuss their ongoing research focusing on Rodin's intrinsic aesthetic realized by his trusted practitioners and preserved in these lifetime casts.