Pottery - Observations On The Materials And Manufacture Of Terra-Cotta, Stone-Ware, Fire-Brick, Porcelain, Earthen-Ware, Brick, Majolica And Encaustic Tiles - International Exhibition, London, 1871 (Paperback)

THE INTERNATIONAL EXHIBITION, LONDON 1871 - POTTERY. I OBSERVATIOSS OK THE NATERIALS AND IIAKUFACTURE OP TEliIL-COlTA, STOYE-WARE, FIRE-BKICK, gurkeXsi, Garfk tx-Wnre, rich, MAJOLICA, AND ENCAUSTIC TILES, WITH REJIARKS ON THE PRODUCTS EXHIBITED - 1872 - PREFACE - IN making a brief report upon tlie Pottery clisl lnyecl in tlle Esliihition, relating to objects of use aud ornai ieatin evcq-house ancl family, the opportunity presentecl itself to esamii et he processes of nlanufacture employecl in the principal 1 rnnchcs of tlie ceramic art. In describing these, I have endeavored to add to the enul icratiola n d treatnient of the mztterials einl lo-ccl a, su iinar o y f their different qualities for their respective uses, together with a lalysis drawl fro111 reliable sources, and a sligllt sketch of the origin and progress of these great inilastrics. To rencler the snl jectm ore intelligil le I, founcl it iinpossiljie not to enter somenl at into technical details, nllich I 1 ope will not proye wholly without interest - INTRODUCTION - THE International Exhibition, held this year in London, contains a very complete collection of Pottery in all its branches. The machinery employed in its manufacture is also exhibited, but only to the extent of a small portion of the various machines employed. The following pages contain a notice of the principal objects of interest in each department, and a summary of the various processes of manufacture, with the differences between them. The composition of almost every kind of Pottery is frequently guarded as a trade secret, but of late years, with indifferent success. The materials available in each locality, which form the basis of local manufactures, differ in their chemical element, and especially in the mdde of their aggregation. In Pottery, the mode of aggregation or grouping of the chemical elements, exerts an all-important influence see Fire-brick, and even when the exact composition of a ware is known, it cannot be reproduced by merely bringing together in correct proportion, the right chemical elements. To use the different available materials, direct experiment with them must be made from the start and as the substances extracted from the earth vary from year t, o year, these experiments must be repeated subsequently, in order to maintain the quality of the products. In the presence of modern chemical analysis and microscopical research, it avails little to keep secret the composition of wares. Analysis reveals the proportion of the primary elements the microscope goes far to determine their mode of grouping and as to the choice of natural materials, this is inevitably, even when the composition is known, the subject of direct experiment. POTTERY WARES. Before proceeding further it may be well to recall that the term Pottery is comprehensive, including all things fashioned of earth and hardened by heat, from the rough baked clay in the shape of bricks and massive articles, to the fine china clay worked up to the lightest and most transparent porcelain. The term Pottery, as distinguished from Porcelain, is sometimes used to indicate only opaque earthen-ware, but the variation in the degree of transparency of semi-vitreous substances is so gradual that the boundary line determining where the one ends and the other begins cannot be well traced. All pottery wares may be divided into unylaxed and uncitr ed ware, which isabsorbent and permeable to water, and glazed and pu tly vitrijied ware, which is non-absorbent and impervious...