Frank Furness (1839-1912), a prolific and acclaimed architect who embraced the materials and vocabulary of the Industrial Age, designed hundreds of buildings in the Philadelphia region. Many of those structures have since been demolished, though Furness’s legacy endures, most notably with his designs for the University of Pennsylvania Fisher Fine Arts Library, the Pennsylvania Academy of the Fine Arts, and the First Unitarian Church of Philadelphia. His legacy also endures because of the influence he wielded over a young Louis Sullivan. Learning from Frank Furness: Louis Sullivan in 1873, an exhibition at the Philadelphia Museum of Art, chronicles how a 17-year-old Sullivan’s brief stint in Furness’s office had more influence over him than his more formal training at the Massachusetts Institute of Technology and the École des Beaux-Arts, as Sullivan himself later admitted. On display: Sullivan’s early drawings and a desk and bookcase designed by Furness, which, in conjunction, help explore how the young architect adopted Furness’s ornamental style and made it his own. The exhibit, supported by a grant from the William Penn Foundation, is one of a series of events that will celebrate the 100th anniversary of Furness’s death. The exhibit runs Oct. 6 through Dec. 30. • philamuseum.org