 Even in Dearinger's excellent compendium of the National Academy of Design, Irwin's studies under Carolus-Duran are erroneously listed as 1867–1869.This comes from the Catalogue of Mark Hopkins Institute, published in 1902, after Irwin's death.The Catalogue of The Southern Exposition in Louisville, published in 1884, while Irwin was still alive, correctly lists his years of study under Carolus-Duran as 1877–1878.