The art Primers of the Pennsylvania Museum and School of Indus trial Art are designed to furnish, in a compact form, for the use of collectors, students and artisans, the most reliable information, based on the latest discoveries, relating to the various industrial arts. Each monograph, complete in itself, contains a historical sketch, a review of processes, descriptions of characteristic examples of the best produc tions, and all available data that will serve to facilitate the identification of specimens. In other words, these booklets are intended to serve as authoritative and permanent reference works on the various subjects treated. The illustrations employed, unless otherwise stated, are reproductions of examples in the Pennsylvania Museum collections. In these reviews of the several branches of ceramics the geographical arrangement used by other writers has given place to the natural or technical classification to permit the grouping of similar wares of all countries and times, whereby pottery, or opaque ware, is classified according to glaze, its most distinctive feature, while, on the other hand, porcelain, or translucent ware, is grouped according to body, or paste. In the preparation of a Primer on Salt Glazed Stoneware the, author has consulted the principal authorities on the subject, and he is particu larly indebted, for many of the facts presented, to The Art of the Old English Potter and The Art Stoneware of the Low Countries and Germany, by M. L. Solon English Earthenware and Stoneware, by William Burton the South Kensington Handbook on English Earthenware, by Prof. A. H. Church, and Early English Pottery, Named, Dated and Inscribed, by John Eliot Hodgkin and Edith Hodgkin. The infor mation contained in these pages will serve to clear up certain disputed points and correct some of the long accepted traditions of ceramic writers which have been found to be erroneous.