Items of particular significance in the collection are copies of letters that Downer sent to Mount Holyoke peers and faculty members, including Mildred Allen. These letters chiefly describe Downer's life and work in China from 1920-1951, reflecting her activities at West China Union University (Hua xi da xue), where she was a physics professor; they frequently include comments on political and world events. Later letters describe her physics work in the Chung Chi College in Hong Kong, 1955-1962, and her activities in retirement. Downer's close relationship with Mount Holyoke's president is reflected by two scrapbooks of clippings, notes and tributes that she complied between 1918 and 1955. Downer's papers also include two physics laboratory manuals in Chinese that she wrote in 1930, and her informational brochure about the West China Union University. Rounding out the collection is biographical information and photographs documenting her life and achievements in China.