Encyclopedia of Marks on American, English, and European Earthenware, Ironstone, and Stoneware: 1780-1980 by Arnold A. Kowalsky and Dorothy E. Kowalsky Very big and heavy book. 640 pages. Good condition. The book is a reference work for collectors of pottery. It identifies thousands of marks from American, English, and European potters. The encyclopedia covers marks and patterns from 1780 to 1980. It focuses on various types of pottery, including blue and white, historic blue, flow blue, mulberry, romantic transferware, tea leaf, and white ironstone. The marks are presented alphabetically by the potter. Each entry provides a brief company history, location, and the years the firm was in operation. The book also includes information on ware types and patterns, a glossary of pottery terms, and an extensive bibliography.