Abstract The Moyer Delwyn Thomas papers (1914-1976) contain colleague files, personal and professional correspondence, financial records, travel information, a bibliography, research files, charts, diagrams, reports, lecture notes, and monographs concerning air pollution. It also contains programs, musical songbooks, and meeting materials for the Gwyn Gnarfu, an American Welsh association. Thomas (1894-1975) was a research chemist for the American Smelting and Refining Company, and senior research...