Catalog E of October 1911 is the second known catalog of the Chelsea Clock Company. Catalog A of 1906, the first catalog, has recently been discovered and is displayed on this website. Catalogs B, C, and D are unknown to present day collectors, and evidence exists that indicates that these letters were not issued to full size catalogs but were issued to supplemental catalogs for autoclocks, etc.. If you know of one of these catalogs please contact the Chelsea Clock Museum.